Internship Report on 'Power Generation, Utilization and Communication System of Marine Vessel

International University of Business Agriculture & Technology

Internship Report:

Power Generation, Utilization and

Communication System of Marine Vessel

Submitted

To

Professor Md. Alimullah Miyan

Vice-Chancellor, IUBAT

By

Mohammad Abu Kawsar Stud Id: 08305058

Bachelor of Science in Electrical and Electronics Engineering

Due date: 10th

August, 2012

Power generation, utilization and communication system of marine vessel M. A. Kawsar (08305058)

page 2

Power Generation, Utilization and Communication System of Marine Vessel

Fig1. showing a cargo vessel, M.V. Kallol anchored in the Chittagong sea port,

where Mr Kawsar is taking his on board training (Source: photo taken with permission from BSC, 2012)

Fig 2. showing M.V. Banglar Urmi anchored in the sea,

the place Mr Kawsar is taking his practical training

(Source: Shipspotting, 2012)


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Request for the Report

10th

August, 2012

Engr. Md. Abul Bashar, Faculty and Course Coordinator,

Department of Electrical and Electronics Engineering,

CEAT, IUBAT, 4 Embankment Drive Road, Sector-10, Uttara Model Town,

Dhaka-1230, Bangladesh

Subject: Request for the report.

Dear Sir,

With due respect I would like to submit my report on Power Generation, Utilization and

Communication System of Marine Vessel as partial fulfillment of Bachelor of Science in

Electrical and Electronics Engineering program. It was excellent opportunity for me to work

with marine electrical equipments to gain theoretical and practical knowledge as well as

useful experience in this area. I would like to have my report to be assessed.

I hope you would be kind enough to evaluate my performance by assessing this report.

Sincerely Yours,

Mohammad Abu Kawsar

ID # 08305058

Program: BSEEE


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Letter of Transmittal

10th

August, 2012

Engr. Md. Abul Bashar, Faculty and Course Coordinator,

Department of Electrical and Electronics Engineering,

CEAT, IUBAT, 4 Embankment Drive Road, Sector-10, Uttara Model Town,

Dhaka-1230, Bangladesh

Subject: Letter of Transmittal of the Practicum Report.

Dear Sir,

I am pleased to submit my practicum report on ‘Power Generation, Utilization and

Communication System of Marine Vessel’. As part of the requirement of the program, I

worked with marine vessel electric and electronic equipments under Bangladesh Shipping

Corporation. It was a challenging work, because in our country Bangladesh Shipping

Corporation is the only government shipping organization which has several ocean going

cargo vessels transporting import and export business world-wide. A lot of marine nautical

and engineering experts are involved in the global transport activities. It was certainly a great

opportunity for me to work on this area to gain theory and practice of the electrical and

electronics appliances required in every life of the marine vessel.

Although, many interruptions have been confronted while working I managed to overcome

all sorts of problem in conducting data and information for this project. I put best of my effort

to achieve my goal to make a pragmatic and useful research report. Thank you.

Sincerely Yours,

Mohammad Abu Kawsar

ID # 08305058

Program: BSEEE


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To Whom It May Concern

This is to certify that Mohammad Abu Kawsar, student of IUBAT has been continuing his

internship program with us from 13th

May, 2012 to till today. The subject matter of the

internship program is “Power Generation, Utilization and Communication System of

Marine Vessel”.

During his internship he has been following instructions according to the satisfaction of the

management. He was very keen to learn the lessons and enthusiastic in completing any

assignment given to him time to time.

I wish your every success with your career.

____________________

Engr. Md. Ahasan-ul-Karim

Asst. General Manager (Marine Workshop)

Bangladesh Shipping Corporation

PABX: +88-031-716330-2, Ext.-104. E-mail: [email protected]


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Student's Declaration

This is to inform that the Practicum Report on Power Generation, Utilization and

Communication System of Marine Vessel has only been prepared as a partial fulfillment of the

Bachelor of Science in Electrical and Electronics Engineering (BSEEE) Program. I hereby

declare that the project embodied in this report in the result of my own handwork and has not

been submitted for another degree to another university.

(Mohammad Abu Kawsar)

ID # 08305058

Program: BSEEE


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Acknowledgement

I would like to thank Professor Md. Alimullah Miyan, the honorable Vice Chancellor for

giving me the opportunity to prepare my research report on the globally important shipping

area. I am highly grateful to my faculty specialist Engr. Md. Abul Bashar, Course

Coordinator of EEE department, Dr. Md. Aziz-ul-Huq, Faculty of EEE department, Engr.

Sadia Sultana Likhan for their valuable guidance and inspiration for the development of this

project.

My special appreciation to Engr. Md. Ahasan-ul-Karim, AGM (Marine Workshop) of

Bangladesh Shipping Corporation, Md. Mazidul Hoque, Chief Engineer and Md. Abdul

Hakim, 4th

Engr. of M.V. BANGLAR URMI for guiding me at workplace, my special

gratitude to Capt. M. A. Rahim, master mariner for his generous recommendation for the on-

board internship for this project.


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Table of Contents

Sl. No. Name Page

1. Introductory Part:

1.1 Origin of the report……….….…...........................................................................12

1.2 Objective………………….….…...........................................................................12

1.3 Scope…………….….….........................................................................................12

1.4 Background………………….................................................................................13

1.5 Methodology…………….….….............................................................................13

1.6 Limitations………………….….…........................................................................14

2. Organizational Overview:

2.1 Profile of BSC…………………………………………….………………..……15

2.2 Mission of BSC…………………………………………………….……...…….15

2.3 Vision of BSC…………………………………….…………………………......15

2.4 Objective of BSC………………………………………………………………..16

2.5 Future Plane of BSC…………………………………………………………….16

2.6 Fleet Profile of BSC…………………………………………….……………….17

2.7 Services of BSC……………………………………………….…...…………….18

3. Hierarchy Level of Onboard Ship’s Personnel:

3.1 Onboard Ship’s organogram …………………………………………………...20

3.2 Hierarchy Level of Deck Department of Onboard Ship…………….……….…21

2.3 Hierarchy Level of Engine Department of Onboard Ship…………….………..23

3.4 Hierarchy Level of Electrical Department of Onboard Ship………….……..….25

4. Overview of Ship’s Electric Power System:

4.1 Introduction……………………………………………………………..………27

4.2 Electric Power Generation System of Onboard Ships………………….…….…28

4.3 Automatic Voltage regulator……………………………………………………34

4.4 How to Synchronize Generators of Onboard Ship? ..............................................37

4.5 Why are Transformer and Alternator Ratings in kVA on Ships? .........................40

4.6 Parallel Operation of Two Generators……………………………………..……41

4.7 Principles of Power Factor………………………………………………….......43

4.8 Automatic Power Factor Improvement Controller (APFIC)……………….…..47

4.9 Emergency Power System of Onboard Ship………………………………..…...51

4.10 Power Distribution System of Onboard Ship……………………….……….….52

5. Overview of Ship’s Power Utilization:


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5.1 Battery Charging System of Onboard Ship………………………….…..….….53

5.2 Navigational Lights Used Onboard Ships…………………………….……......56

5.3 Different Types of Alarms of Onboard Ships……………………………….....58

5.4 Single Phasing in Electrical Motors: Causes, effects, & protection methods.....60

5.5 Maintenance of Electrical Relay on Ships Electrical Circuit……………...…...63

5.6 How to Install Electronic Circuits on Ship? ........................................................65

5.7 Procedure for Starting Emergency Steering System of Ship………………......68

5.8 General Overview of Types of Pumps on Ship………………………….…….70

5.9 The Basics of Air Compressor of Onboard Ship………………………..…….72

5.10 Construction and Working of Ships Refrigeration Plant……………………..74

5.11 How to Find an Earth Fault On board Ships?.....................................................76

5.12 How to Minimize the Risks of an Electrical Shock of Onboard Ship?.............79

6. Overview of Ship’s Communication System:

6.1 Overview of Radar………………………………………………….……...….80

6.2 Overview of LRIT…………………………………….……….…….………..85

6.3 Electronics Navigation..............................................................................……..88

6.4 AIS Transponders......................................................................................…….89

6.5 Marine VHF Radio…………………………………………………….……...89

6.6 Ship’s Voyage Data Recorders (SVDR)…………………………………..…..90

7. Conclusions:

8. Recommendations………………………………………………………………......91

9. References ………………………………………………………………………….92

9.1 Online resources………………………………………………………………92

9.2 Bibliography…..………………………………………………………………92

10. Appendix………………………………………………………………………….94

10.1 List of acronyms……………………………………………………………....94

10.2. Glossary……………………………………………………………………….97

10.3 Photo/pictures/videos………………………………………………………….100

List of Figures

Fig No. Figures page

Fig 1. Photo of Banglar Kallol 2

Fig 2. Photo of Banglar Urmi 2

Fig 3. Organogram of Onboard Ship’s Personnel 19

Fig. A Ship Master/Captain on navigational operation 22

Fig. A Ship Chief Officer on navigational operation 23

Fig. A Chief Engineer working on ship’s control board 25

Fig. A switchboard, fault detected in Banglar Urmi by a trainee E/Engineer 25

Fig. 850 KVA Generator operated by a trainee Electrical Engineer in Banglar Urmi 28

Fig. Magnetization of the rotor winding, Left: Brushed;

Right: Brush-less magnetization 30

Fig. Two Types of Rotor Construction:


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(a) Cylindrical Type Rotor and (b) Salient Type Rotor 33

Fig. Over all Circuit of AVR for the Diesel Engine Type Synchronous Generator 35

Fig. AVR Design for the Diesel Engine Type Synchronous Generator 36

Fig. Circuit Diagram of Synchroscope Method 37

Fig. Circuit Diagram of Emergency Synchronizing Lamps Method 38

Fig. Two Generators Set in M.V. Banglar Kallol 41

Fig. Circuit Diagram of Generators Set in MV Banglar Kallol 42

Fig. Vector Diagram of Parallel Operation,

Fig-4.6.2 Generators Governor Characteristic

Fig-5.5.2 Location of Installation, where installed PCB,

Fig-5.7.1 Steering Motor,

Fig-5.7.2 Procedure of Steering Operation,

Fig-5.8.1 Positive Displacement Pump,

Fig-5.8.2 Dynamic pressure pumps,

Fig-5.9.1 Main air compressor

Fig-5.10.1 Refrigeration Plant

Fig-5.11.1 Finding Earth Fault on 440V circuit, Ref. ABB Marine

Fig-5.11.2 Earth Fault Detecting on 440V circuit, Ref. ABB Marine

Fig-6.1.1 Commercial marine radar antenna, Ref. M.V. BANGLAR URMI

Fig-6.1.2 An Electrical Engineer is operating the radar (Left), Display of Radar Screen (Right)

Fig-6.1.3 Over all connection diagram of radar signal processing

Fig-6.2.1 Data exchange system of LRIT, Ref. ABB Marine

Fig-6.3.1 Eleectronics Navigation

Fig-6.6.1 Location of SVDR

List of Table

No. Table page

Table 1 A fleet profile of BSC 17

Table 2 Results of field voltage and field current when the input voltage fluctuation occurred 36


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Executive Summary

Ship power supply system consists of ship power plants and auxiliary systems. In accordance

with the most popular classification, power plants can be classified by source of energy (coal,

diesel, petrol, natural gas, hydropower, geothermal, solar, wind and nuclear, etc) or

operational principle (steam, turbine, etc).

The most commonly encountered type is diesel power plant. It is used in 90% of ships. In

addition to high power, it has relatively small dimension which is very important at sea.

Other plants (gas and steam turbine or nuclear plant) also have their own strong points and

are used on various ships. Altogether, selection of optimum ship power plant depends on

type, dimensions, proposed characteristics and conditions of operation of a vessel.

Each system studied employed rotating machines that were built using HTS (high

temperature superconductor) wires. The software enabled modeling of electrical systems with

full transient details to study the dynamic response of the electric system over a wide

frequency range. The default models and standard features available in online served all the

requirements. A number of fault and load scenarios were studied. The goal of this simulation

work was to develop a model for studying the dynamic behavior of the ships electrical

system. This goal was successfully achieved.

Recent advances in the development of all electric ships for the U.S. Navy indicate that the

total power requirements on large surface ships could approach 100 MW. New technologies

and techniques are emerging that manage the generation and utilization of the anticipated

power level. As the power level and the number of critical electrical components on the ship

increase, so does the complexity of analyzing the system. Traditionally, naval ships had

relatively low electric power and simple electric systems, which could be analyzed using

simple calculations. As a result, the experience in the application of advanced dynamic tools

to analyze power systems of large combatant electric ships is limited. This report shows how

a power system simulation tool could be used to study the ship electrical system dynamics.


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1. Introductory Part

1.1 Origin of the Report

This report on “Power Generation, Utilization and Communication System of Marine

Vessel” is prepared by Mohammad Abu Kawsar for the Bachelor of Science in Electrical

and Electronics Engineering program for the department of Electrical & Electronics

Engineering under IUBAT (International University of Business Agriculture and

Technology) as an integral part of the internship. He has done this practicum report based on

onboard ships of Bangladesh Shipping Corporation, under the supervision of Engr. Md.

Ahasan-ul-Karim, Assistant General Manager (BSC Marine Workshop), Saltgola,

Chittagong.

1.2 Objectives

Broad Objective

The broad objective of the report has been made on Power Generation, Utilization and

Communication System of onboard ships of Bangladesh Shipping Corporation.

Specific Objectives

The specific objectives of this report include:

Studying on power generation system of marine vessels,

Identifying the different types of problem which arise for power generation and

utilizations, and

Studying on communication system and electronic navigation of marine vessels.

1.3 Scope

Electrical installations are present in any ship for empowering of communication and

navigation equipment, alarm and monitoring system, running of motors for pumps, fans or

winches, high power installation for electric propulsion.

Electric propulsion is an emerging area where various competence areas meet. Successful

solutions for vessels with electric propulsion are found in environments where naval


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architects, hydrodynamic and propulsion engineers, and electrical engineering expertise

cooperate under constructional, operational, and economical considerations.

1.4 Background

The concept of electric propulsion is not new; the idea originated more than 100 years ago.

However, with the possibility to control electrical motors with variable speed in a large

power range with compact, reliable and cost competitive solutions, the use of electrical

propulsion has been emerged in new application areas.

Electric propulsion with gas turbine or diesel engine driven power generation is used in

hundreds of ships of various types and in a large variety of configurations. Installed electric

propulsion power in merchant marine vessels was the range of 6-7 GW (Giga Watt) in 2002,

in addition to a substantial installation in both submarine and surface war ship applications.

At present, electric propulsion is applied mainly in following type of ships: Cruise vessels,

ferries, DP drilling vessels, thruster assisted moored floating production facilities, shuttle

tankers, cable layers, pipe layers, icebreakers and other ice going vessels, supply vessels, and

war ships. There is also a significant on-going research and evaluation of using electric

propulsion in new vessel designs for existing and new application areas.

1.5 Methodology

Both primary and secondary data has been collected for the purpose of this report that is

concentrated to on-board Ships of Bangladesh Shipping Corporation.

Primary Data

Primary data are collected from the ships while working on-board, books about marine power

generation, the user manual handbook of Electrical equipment and personal meet to the host

supervisor, Electricians of BSC Marine Workshop and engine room operation manuals.

Secondary Data

Secondary data has been collected from the online resources.


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1.6 Limitations

This report is also having some limitations as I didn’t get a soft copy of datum or help from

on-board mariners. I have seen that most marine officers and marine engineers are very

overconfident and stubborn. They don’t want to provide any information to internship

candidates, like me, while working on-board ships. I had little chance to take photos and

other information because the engine and control room is a restricted and sensitive area. As I

was very new there, they didn’t allow me the spontaneous access to all of the equipment and

which prevents me from collecting sufficient information as I desired to.

2. Organizational Overview

2.1 Profile of Bangladesh Shipping Corporation

The Bangladesh Shipping Corporation, a state owned and managed public sector

Corporation, is the largest ship owner in Bangladesh. It was established on 5th February 1972

under President’s Order No. 10 of 1972 with the objectives of providing efficient, safe,

reliable and economic shipping services to the local exporters, importers and business houses,

to develop sustainable shipping and ancillary infrastructures in a sovereign nation which just

became independent on 16th December 1971 after a nine month long liberation war and

thereby reducing dependence on foreign flag vessels to stop drainage of hard earned foreign

exchange from the national exchequer.

BSC is managed by the managing director, directors, a secretary, a general manager, an

assistant general manager and office staff headed by the shipping minister as ex officio

chairman. The corporation did not have any ship at the beginning when it started working as

agents for other shipping company.

The Board of Directors for BSC is formed by the Hon'ble Minister for Shipping as its ex

officio Chairman, Secretary, Joint Secretary, Finance Division, Ministry of Finance,

Managing Director, Executive Director (Finance), Executive Director (Commercial) and

Executive Director (Technical) of BSC as members.


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The head office of BSC is situated in Chittagong, Bangladesh with branch offices in Dhaka

and Khulna. All of its offices are dealing in marketing and chartering ships. The marketing

department takes care of maintaining the corporation's ships and the chartering department

looks after the chartering ships, maintaining public relations and recruiting officers and staff.

It maintains offices in Singapore and London.

The corporation owned its first ship Banglar Doot in 1974. By 2001 it had 13 ships,

including 2 oil tankers. It charters out its container ships and tankers and also charters in

ships from other companies.

The BSC has been playing a significant role in exporting and importing oil products,

readymade garments, machinery and food stuff. The biggest vessel is considered to be

Banglar Doot (carrying capacity 16,771MT) and Banglar Kakali (carrying capacity

16,764MT). The corporation has two dockyards one at Khulna and other at Chittagong where

its ships are being maintained regularly.

2.2 Mission of BSC

To provide safe and efficient shipping services on international routes and to carry out all

forms of activities connected with or ancillary to shipping as national flag carrier and thereby

contributing to the national economy.

2.3 Vision of BSC

We want to emerge as a respectable competitor in all the sectors of shipping industry in

which we compete. We are optimistic that accomplishment of our corporate goals and

objectives will be founded on our absolute dedication, integrity, and sincerity to serve up to

the satisfaction of our clients, associates and partners through constant innovation,

operational excellence, cost effectiveness and the talents of our people.

2.4 Objectives of Bangladesh Shipping Corporation

To acquire, charter, hold or dispose of ships or crafts,

To provide safe, reliable, efficient and economic shipping services,


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To promote any organization, in or outside Bangladesh, for the purpose of engaging

in any activity falling within the function of the Corporation, or to associate with any

such organization,

To undertake the repairs, overhaul construction, reconditioning or assembly of ships,

vessels and other vehicles,

To assemble, manufacture, recondition, overhaul and repair machines, parts,

accessories and instruments pertaining to ships, vessels and other vehicles,

To establish institutes or make other arrangements for the instruction and training of

persons engaged or likely to be engaged in any activities connected with or ancillary

to shipping,

To acquire, hold or dispose of any property, whether moveable or immovable,

To be a profitable and commercially viable organization and contribute to the national

economy by securing a reasonable share of the country’s total export and import

through sea.

2.5 Future Plan of Bangladesh Shipping Corporation

Bangladesh Shipping Corporation has been relentlessly trying for balancing and modernizing

the national fleet under replacement and expansion scheme. With this in mind, a fleet

planning study was conducted. A strategic plan was sketched to build up a mixed fleet of 24

vessels with an aim of acquiring 15 ships (1 second hand mother tanker, 8 second hand / new

full cellular container vessels and 6 second hand multipurpose cargo vessels) gradually

during the time scale started from the fiscal year 1996-97 to 2004-2005. Unfortunately due to

non-availability of fund BSC could not procure any ship according to the plan. Nevertheless,

in accordance with present trend of the shipping trade BSC has been trying to acquire

container vessels on priority basis.

2.6 Fleet Profile of Bangladesh Shipping Corporation

Table1. The fleet profile of BSC

Sl.

No

Name of Vessels Year of

Built

Country of

Built

DWT GRT Class Date of

Acquisition

1 M.V. Banglar Kakoli 1979 Japan 17234 12521 BV 18-12-1979

2 M.V. Banglar Kallol 1980 Japan 17222 12521 BV 24-01-1980

3 M.V. Banglar Mamata 1980 Japan 15877 11764 BV 04-06-1980

4 M.V. Banglar Maya 1980 Japan 15833 11764 BV 10-09-1980

5 M.V. Banglar Robi 1981 East

Germany

12720 10383 BV 07-01-1983

http://www.bsc.gov.bd/index.php?cPath=BANGLAR%20KALLOL

http://www.bsc.gov.bd/index.php?cPath=BANGLAR%20MAMATA

http://www.bsc.gov.bd/index.php?cPath=BANGLAR%20MAYA

http://www.bsc.gov.bd/index.php?cPath=BANGLAR%20ROBI


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6 M.V. Banglar Gourab 1983 France 13934 9782 BV 21-01-1983

7 M.V. Banglar Moni 1983 East

Germany

12680 10383 BV 09-09-1983

8 M.T. Banglar Jyoti 1987 Denmark 14541 8672 BV 15-05-1987

9 M.V. Banglar Urmi 1984 Spain 15552 9840 BV 14-07-1987

10 M.T. Banglar Shourabh 1987 Denmark 14541 8672 BV 14-10-1988

11 M.V. Banglar Doot 1988 China 16771 13125 BV 12-12-1988

12 M.V. Banglar Mookh 1989 China 16769 13125 BV 12-10-1989

13 M.V. Banglar Shikha 1991 China 12945 9927 BV 16-07-1991

2.7 Services of Bangladesh Shipping Corporation

2.7.1 Bangladesh-Pakistan-West Asia Gulf Liner Service

From 1980 BSC is regularly operating vessels in the Bangladesh-Pakistan-West Asia Gulf

Liner route. BSC offers monthly sailing in this route.

2.7.2 Bangladesh/UK-Continent/Africa Liner Service

Since inception BSC has been operating liner service in the Bangladesh/UK-Continent/Africa

route on regular basis.

Due to rapid containerization of break bulk cargoes, the pattern of sea borne trade has been

changed radically over the last one decade and as such the traditional liner service of break-

bulk cargo vessels between Bangladesh/UK-Continent and African routes became

economically non-viable. Besides due to the increasing number of regulations enacted by

IMO the regulatory bodies in the European Union ratified their shipping policies and set a

very high standard for the vessels calling European ports. It has become a rigorous task for

the ship owners to maintain an aged traditional liner vessel up to such a high standard. Under

the circumstances BSC had to suspend its regular liner service between Bangladesh/UK-

Continent ports and the Africa service since year 2000. However, procurement of new vessels

may open opportunities in future to reopen the liner service subject to the inducement of

sufficient cargo.

2.7.3 Bangladesh/Far East/Japan Liner Service

BSC started its regular liner service in the Bangladesh/Far East/Japan route from 1980. But

due to scarcity of export cargo from Bangladesh to Far East BSC's service in Bangladesh/Far

East/Japan route was suspended since 1998. In order to retain the membership of Benjap

http://www.bsc.gov.bd/index.php?cPath=BANGLAR%20GOURAB

http://www.bsc.gov.bd/index.php?cPath=BANGLAR%20MONI

http://www.bsc.gov.bd/index.php?cPath=BANGLAR%20JYOTI

http://www.bsc.gov.bd/index.php?cPath=BANGLAR%20URMI

http://www.bsc.gov.bd/index.php?cPath=BANGLAR%20SHOURABH

http://www.bsc.gov.bd/index.php?cPath=BANGLAR%20DOOT

http://www.bsc.gov.bd/index.php?cPath=BANGLAR%20MOOKH


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Conference BSC’s sailing right has been sublet to an active Benjap Conference member

Everett Orient Line.

2.7.4 Chartering & Tramping Service

BSC engages its vessels both on time and voyage charter. At present most of the vessels are

under time charter to various local and foreign companies. With these vessels charterers are

operating tramp services in the ports of South America to East/West Africa and Sub-

Continent to Middle East/Gulf region.

2.7.4 Crude Oil Lightening

BSC provides crude oil lightening service to BPC (Bangladesh Petroleum Corporation) for

carrying crude oil from the mother vessels anchored at Kutubdia outer anchorage to ERL

(Eastern Refinery Limited) shore tank as their lighterage contractor with the two purposes

built lighter vessels M.T. Banglar Jyoti and M.T. Banglar Shourabh.

2.7.5 Food Grain Carrying

Bangladesh Shipping Corporation provides Ministry of Food a total transportation solution

for carriage of food grain from Australia and Canada. It organizes to carry wheat in bulk from

Australia and Canada once a year by hiring mother vessels.

2.7.5 Food Grain Lightening

BSC as lighterage contractor provides food grain lightening service to Food Department

under Ministry of Food of Bangladesh Government for carrying bulk wheat from the mother

vessel anchored at Kutubdia or outer anchorage of Chittagong Port to Grain Silo Jetty at

Chittagong or Khulna.

2.7.6 Ship Repair

BSC has its own marine workshop situated on the bank of the river Kharnaphully to carry out

maintenance and repair of BSC vessels during vessel’s stay at Chittagong. The workshop is

well equipped and situated in a very good strategic place to provide repair service to the


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vessels calling Chittagong. BSC Marine Workshop not only provides repairing service to

BSC vessels but also to local private vessels.

3. Hierarchy Level of Onboard Ship’s Personnel

3.1 Onboard Ship’s Organogram

Basically crew on ship is divided into two departments; Deck and Engine Department. For a

safe and perfect sailing these department play vital role.

Fig 3. Organogram of Onboard Ship’s Personnel


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3.2 Hierarchy Level of Deck Department of Onboard Ship

Introduction

The deck department is concerned with the effective management of vessel crew; maintaining

proper watches; maintaining vessel logs for company and customer; maneuvering vessel in

port at various docks and offshore at various offshore facilities; general navigation of vessel

and overseeing the enforcement of and adherence to all company policies and procedures on

board as described under SEACOR's Safety Management System (SMS) manual.

Duties of Captain/Master

Fig 4. showing the Ship Captain on navigational operation

(Ref. marineinsight.com)

The captain is in overall command of a Merchant Ship and is responsible for the safety,

efficiency and commercial feasibility of his ship. His duties are navigational at sea. While in

ports he is responsible for cargo operations. He maintains orderliness and discipline in the

ship. He ensures safety of officer’s crew and the cargo and assigns organizational duties for

ship's operation, navigation and maintenance of the ship. He acts as the ship owner's

representative with all outside parties. He implements the company's policies for operations

and safety and the commercial instructions that may be given by the owners time to time. He

is also the legal head of the ship.


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Duties of Chief Officer

The Chief Officer as he is often called is second in position to the Captain. He is in charge of

the deck department and also the deck crew. He oversees all the cargo operations including

its handling and stability. He is also responsible for training the deck crew in safety and

rescue operations besides other emergency procedures. He is also given the duty as ship

security officer in most of the ships.

Fig 5. showing a Chief Officer on navigational operation

(Ref. marineineinsight.com)

Duties of Second Officer

The Second Officer is responsible for all the navigation and holds his rank below the Chief

Officer. A second officer has the responsibility of maintaining the charts and also plots the

routes for navigation. Although on various oil tankers a second mate may assist the chief

officer for tank cleaning and maintenance as well. A second officer keeps the 12:00-04:00 at

night and 12:00- 16:00 watch in the evening.

Duties of Third Officer

The Third Officer is responsible for all the safety related operations onboard which include

regular maintenance of all the firefighting equipment and lifeboats. He is the most junior

officer of the deck department and also keeps the 08:00-12:00 and 20:00-12:00 evening

watch.


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Duties of Deck Cadet

A deck cadet is more of a marine graduate who works directly under the chief officer on the

ship. Normally a deck cadet has to complete one full year of training on board under the

senior ranks.

3.3 Hierarchy Level of Engine Department of Onboard Ship

Introduction

Engine Department is most important equipment of ship organization for safe and economic

sealing in sea. Marine engineers are responsible for maintenance of the engine room. The

chief engineer and ship engineer are responsible for ensuring that all planned mechanical and

electrical maintenance takes place and Co-ordinates operations with shore-side port engineer.

With the supervision of chief engineer whole department performs all technical aspect which

is required for perfect and smooth running of the ship.

Duties of Chief Engineer

The chief engineer is head of engine department which is responsible for the entire technical

operations of the vessel including engineering electrical and mechanical divisions. The whole

engine department is worked under the supervision and command of chief engineer.

Fig 6 showing a Chief Engineer working on ship’s control board

(marineinsight.com, 2012)

Duties of the chief engineer in both general and emergency conditions on the ship are:


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Chief engineer ensures that all the ship’s machinery and equipment are working in

efficient manner in order to support safe navigation of the ship.

Frequent inspections of equipment dealing with ship and personal safety must be

carried out by him at regular interval of time.

Duties of Second Engineer

The second engineer performs daily maintenance and operations of the engineering and

technical aspect of ship in the command of Chief Engineer and in some cases 1st Engineer.

Second engineer is known as a watch keeping engineer who watches and assign repair and

maintenance duties to crew in engine room.

Duties of Third Engineer

The third engineer is responsible for maintenance and repair of engines and its relative

equipments in ship. All the engine crews work under the guidance of Third Engineer.

Duties of Fourth Engineer

The fourth engineer should take a thorough round of the engine department with the signing

off engineer and do a proper taking over of the duties. He should check general condition of

machinery and special procedure for operation. Condition and layout of bunkering system

including valve operation, tanks and sounding pipe location should be checked. Daily

consumption of lube oil, fuel oil, marine diesel or gas oil and cylinder oil for daily record

keeping in sounding log is to be maintained.

After completion of the engine room round together, the 4th

Engineer shall report the details

to the 2nd

engineer and notify discrepancies observed, if any.

Duties of Engine Cadet

Stands engine room watch, assist engine cadet with control room operations and maintain the

shipboard propulsion equipment and auxiliary machinery. He should check Inventory and

location of pumps spares and tools.


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3.4 Hierarchy Level of Electrical Department of Onboard Ship

Introduction

All the machinery onboard ship is a combination of mechanical and electrical systems. The

modern day shipping is more reliable on automations and electronics whose knowledge and

maintenance can only be handled by an engineer expert in the electrical field. Marine

electrical engineers are perfect for such jobs and for this they hold an important role on board

and in offshore industry.

Duties of Electrical Engineer on board Ship

Electrical Engineer is one of the most vital positions in the technical hierarchy of a ship and

an engineer is responsible for his assigned work under the command of Chief Engineer.

Fig. 7 showing a switchboard, fault detected in M. V. BANGLAR URMI by a trainee Electrical Engineer

(Photo was taken while Mr. Kawsar working on board)


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The general duties of electrical engineer are:

He is responsible for maintenance of all the electrical motors on ship i.e. in engine

room and on deck,

He is in charge of maintenance of all switchboard including main switchboard and

emergency switchboard,

He is responsible for maintenance of fire detectors and fire alarm system,

He has to maintain all the ship’s alarm system,

He is responsible for the electronic system fitted onboard ship,

He is responsible for the ship’s navigational lights and other navigational equipments,

He is responsible for all the batteries that are connected to machineries onboard. It

includes:

- Emergency batteries for alarm and lights,

- Batteries for emergency generator,

- Other batteries fitted onboard.

He is responsible for maintaining refrigeration unit in the engine room,

He has to take care of air conditioning unit of the vessel,

Electrical officer is responsible for maintaining refrigerated containers carried on

container ship,

He is responsible for cargo and engine room cranes electrical system.

He has to carry out routine maintenance for main engine alarms and trips along with

the chief engineer,

During the time of maneuvering, he has to be present in the engine room along with

other engineers to tackle any kind of electrical and other emergencies,

Electrical officer can assist in watch keeping routines at desired time by the chief

engineer,

He has to assist ship’s engineer and deck officer in all kind of electrical problems.


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4. Overview of Ship’s Electric Power System

4.1 Introduction

The main difference between the marine and a land-based electrical power system is the fact

that the marine power system is an isolated system with short distances from the generated

power to the consumers, in contrast to what is normal in land-based systems where there can

be hundreds of kilometers between the power generation and the load, with long transmission

lines and several voltage transformations between them. The amount of installed power in

vessels may be high and this gives special challenges for the engineering of such systems.

High short circuit levels and forces must be dealt with in a safe manner. The control system

in a land-based electrical power system is divided in several separated sub-systems, while in

a vessel; there are possibilities for much tighter integration and coordination.

The design of power, propulsion and control systems for a vessel have undergone significant

changes and advances over a relatively recent period of time. Because of the rapidly

expanding capabilities of computers, microprocessors and communications networks, the

integration of systems which were traditionally separate, stand alone systems is now not only

feasible, but fast becoming industry standards. The increasing demand for redundant

propulsion and Dynamic Positioning (DP) class 2 and class 3 vessels requires system

redundancy with physical separation. The interconnections of the diverse systems on a vessel

have become increasingly complex, making the design, engineering and building of a vessel a

more integrated effort.

Merchant Ships use three phase power generated and distributed in an ungrounded delta

configuration. Ungrounded systems are used to ensure continued operation of the electrical

system despite the presence of a single phase ground. The voltages are generated at levels of

450 volts a.c. at 60 hertz. The most popular topology used in Marine electrical system is a

ring configuration of the generators which provides more flexibility in terms of generation

connection and system configuration. In this type of topology, any generator can provide

power to any load. This feature is of great importance in order to ensure supply of power to

vital loads if failure of an operating generating unit occurs.


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4.2 Electric Power Generation System of Onboard Ships

A ship is like a floating city with all the privileges enjoyed by any normal land city. Just like

a conventional city, the ship also requires all the basic amenities to sustain life on board; the

chief among them is power or electricity. In this article we will learn as to how power is

generated and supplied on board a ship. Shipboard power is generated using a prime mover

and an alternator working together. For this an alternating current generator is used on board.

The generator works on the principle that when a magnetic field around a conductor varies, a

current is induced in the conductor.

Fig. 8 showing the 850 KVA Generator operated by an Electrical Engineer in M. V. BANGLAR URMI

(Photo was taken while Mr Kawsar working on board)

The generator consists of a stationary set of conductors wound in coils on an iron core. This

is known as the stator. A rotating magnet called the rotor turns inside this stator producing

magnetic field. This field cuts across the conductor, generating an induced EMF or electro-

magnetic force as the mechanical input causes the rotor to turn.


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The magnetic field is generated by induction (in a brushless alternator) and by a rotor

winding energized by DC current through slip rings and brushes. Few points to be noted

about power on board are:

AC, 3 phase power is preferred over DC as it gives more power for the same size.

3 phases is preferred over single phase as it draws more power and in the event of

failure of one phase, other 2 can still work.

Prime Mover

The source for power is most often a generator set driven by a combustion engine which is

fueled with diesel or heavy fuel oil. Occasionally one can find gas engines and also gas

turbines, steam turbines or combined cycle turbines, especially for higher power levels, in

light high-speed vessels, or where gas is a cheap alternative (e.g., waste product in oil

production, boil-off in LNG carriers, etc.).

In a diesel-electric propulsion system, the diesel engines are normally medium to high-speed

engines, with lower weight and costs than similar rated low speed engines that are used for

direct mechanical propulsion. Availability to the power plant is of high concern and in a

diesel electric system with a number of diesel engines in a redundant network; this means

high reliability but also sophisticated diagnostics and short repair times.

The combustion engines are continuously being developed for higher efficiency and reduced

emissions, and at present, a medium speed diesel engine has a fuel consumption of less than

200g per produced kWh at the optimum operation point.

Moreover, the efficiency drops fast as the load becomes lower than 50% of MCR (Max

Continuous Rating). At this working condition, the combustion is inefficient and with a high

degree of soothing which increases the need for maintenance. In a diesel electric system with

several diesel engines it is hence an aim to keep the diesel engines loaded at their optimum

operating conditions by starting and stopping generator sets dependent on the load with an

aim to keep the average loading of each diesel engine closest possible to its optimum load

point.


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Generators

The majority of new buildings and all commercial vessels have an AC power generation plant

with AC distribution. The generators are synchronous machines, with a magnetizing winding

on the rotor carrying a DC current and a three-phase stator winding where the magnetic field

from the rotor current induces a three-phase sinusoidal voltage when the rotor is rotated by

the prime mover. The frequency f [Hz] of the induced voltages is proportional to the

rotational speed n [RPM] and the pole number p in the synchronous machine:

A two-pole generator will give 60 Hz at 3600 RPM, a four-pole at 1800 RPM, and a six-pole

at 1200 RPM, etc. 50 Hz is obtained at 3000 RPM, 1500 RPM, and 1000 RPM for two-pole,

four-pole, and six-pole machines. A large medium speed engine will normally work at 720

RPM for 60 Hz network (10 pole generator) or 750 RPM for 50 Hz networks (8 pole

generator).

The DC current was earlier transferred to the magnetizing windings on the rotor by brushes

and slip rings. Modern generators are equipped with brushless excitation for reduced

maintenance and downtime, Fig. 4.2. The brush-less excitation machine is an inverse

synchronous machine with DC magnetization of the stator and rotating three-phase windings

and a rotating diode rectifier. The rectified current is then feeding the magnetization

windings.

Fig - 9 Magnetization of the rotor winding, Left: Brushed; Right: Brush-less magnetization.


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The excitation is controlled by an automatic voltage regulator (AVR), which senses the

terminal voltage of the generator and compares it with a reference value. Simplified, the

controller has PID characteristics, with stationary limited integration effect that gives a

voltage drop depending on the load of the generator. The voltage drop ensures equal

distribution of reactive power in parallel-connected generators. According to most applicable

regulations, the stationary voltage variation on the generator terminals shall not exceed

±2.5% of nominal voltage. Also, the largest transient load variation shall not give voltage

variation exceeding -15% or +20% of the nominal voltage unless other has been specified and

accounted for in the overall system design. In order to obtain this transient requirement, the

AVR is normally also equipped with a feed-forward control function based on measuring the

stator current.

In addition to the magnetizing winding, the rotor is also equipped with a damper winding

which consists of axial copper bars threaded through the outer periphery of the rotor poles,

and short circuited by a copper ring in both ends. The main purpose of this winding is to

introduce an electromagnetic damping to the stator and rotor dynamics. A synchronous

machine without damper winding is inherently without damping and would give large

oscillations in frequency and load sharing for any variation in the load.

The stationary, transient and sub-transient models are known from the theory of synchronous

machines. Simplified one could say that the flux linkages in the damper winding, which are

“trapped” and resist changes due to being short-circuited, characterize the sub-transient

interval.

This is observed as an apparent lower inductance in the generator, which gives a stiffer

electric performance during quick load variations, and helps to reduce transient voltage

variations and the voltage variations due to harmonic distortion in load currents. This effect is

only contributing for dynamic variations faster than characterized by the sub-transient time

constant such as the first period of motor start transients and transformer inrush, and for

harmonic distorted load currents.

Often, the generators are connected to a propulsion engine’s shaft, i.e. a shaft generator. The

shaft generators are in some applications made for two-directional power flow, which means

that it can be run as motor.


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This principle may be called a PTI-PTO concept (Power take-in – Power take out). Shaft

generators have the disadvantage of forcing the main propeller to work at fixed speed if the

generator output shall have constant frequency. This will reduce the efficiency of the

propeller in low load applications. Static converters may be installed to keep fixed frequency

for variable speed.

Synchronous Alternator

Synchronous alternators are the main machines used for the generation of electrical energy.

They are intended to supply electrical power to the final loads through transmission and

distribution systems. Besides, without going into technical details, by acting on the excitation

of alternators, it is possible to vary the value of the generated voltage and consequently to

regulate the injections of reactive power into the network, so that the voltage profiles of the

system can be improved and the losses due to joule effect along the lines can be reduced.

Principles of Synchronous Generator

The operation of a generator is based on Faraday’s law of electromagnetic induction. If a coil

or winding is linked to a varying magnetic field, then electromotive force or voltage is

induced across the coil. Thus, a generator has two essential parts: one that creates a magnetic

field and the other where the energy is induced. The magnetic field is typically generated by

electromagnets.

These windings are called field winding or field circuits. The coils where the electro motive

force energies are induced are called armature windings or armature circuits. With rare

exceptions, the armature winding of a synchronous machine is on the stator, and the field

winding is on the rotor. The field winding is excited by direct current conducted to it by

means of carbon brushes bearing on slip rings or collector rings.

The rotor of the synchronous generator may be cylindrical or salient construction. The

cylindrical type of rotor has one distributed winding and a uniform air gap.

These generators are driven by steam turbines and are designed for high speed 3000 or 1500

rpm (revolution per minute, two and four pole machines respectively) operation. The rotor of


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these generators has a relatively large axial length and small diameter to limit the centrifugal

forces.

The salient type of rotor has concentrated windings on the poles and non-uniform air gaps. It

has a relatively large numbers of poles, short axial length, and large diameters. The

generators in hydroelectric power stations are driven by hydraulic turbines and they have

salient pole rotor construction. The cylindrical and salient type rotors are shown in Figure (1).

The rotor is also equipped with one or more short-circuited windings known as damper

windings. The damper windings provide an additional stabilizing force for the machine

during certain periods of operation. When a synchronous generator supplies electric power to

a load, the armature current creates a magnetic flux wave in the air gap which rotates at

synchronous speed. This flux reacts with the flux created by the field current, and

electromagnetic torque results from the tendency of these two magnetic fields to align. In a

generator this torque opposes rotation and mechanical torque must be applied from the prime

mover to sustain rotation. As long as the stator field rotates at the same speed as the rotor and

no current is induced in the damper windings. However, when the speed of the stator field

and the rotor become different, currents are induced in the damper windings. Currents

generated in the damper windings provide a counter torque. In this way the damper windings

can keep the two speeds. Two types of rotor has been displayed in the following.

Fig 10. Two Types of Rotor Construction: (a) Cylindrical Type Rotor and (b) Salient Type Rotor

(Ref. marineinsight.com, 2012)

4.3 Automatic Voltage regulator

A voltage regulator is defined as a device for varying the voltage of a circuit or for

automatically maintaining it at or near a prescribed value. From this, it would appear that the


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term automatic voltage regulator covers the apparatus used in the methods of obtaining a

constant voltage.

A voltage regulator is designed to automatically maintain a constant voltage level. A voltage

regulator may be a simple "feed-forward" design or may include negative feedback control

loops. It may use an electromechanical mechanism, or electronic components. Depending on

the design, it may be used to regulate one or more AC or DC voltages.

Electronic voltage regulators are found in devices such as computer power supplies where

they stabilize the DC voltages used by the processor and other elements. In automobile

alternators and central power station generator plants, voltage regulators control the output of

the plant. In an electric power distribution system, voltage regulators may be installed at a

substation or along distribution lines so that all customers receive steady voltage independent

of how much power is drawn from the line.

Circuit Design of the AVR for the Synchronous Generator

The circuit arrangement of the field control circuit of the synchronous generator is shown in

Fig.7. In this system, the output voltage of the generator is sampled through the transformer

and is rectified by simple circuit and the bridge rectifier. In the initial state condition, the

output of the generator may be 25V or 30V which depends on the electromagnetic field in the

machine, at the time, the 12V relay is normally close position. At the time, the gate voltage is

fed to the synchronous generator field coil until the output voltage is 230V. Now, 12V relay

is normally open position.

When the mains supply voltage falls, Q2 produce negative current to the bridge circuit and

the bridge circuit supplies positive current to the gate of SCR and the required current is fed

to the field coil and the output voltage of the synchronous generator is increased.

When the output is 230V, the output positive current of the bridge is balanced with the output

negative current of the Q1.

When the main supply voltage raises, Q2 will give a little current is fed to the gate of SCR

and the required field current is fed to the field coil and absorbs the required reactive power

from the supply line.


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Fig 11. Over all Circuit of AVR for the Diesel Engine Type Synchronous Generator



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Fig 12. AVR Design for the Diesel Engine Type Synchronous Generator

Tests and Results

These results are obtained by feeding the variable over or under input voltage to the

electronic control circuit, and 100 watts bulb is used as a field coil. The output of the

generator voltage must be stable although the various input voltage pass through electronic

control circuit.

Table 2

Results of field voltage and field current when the input voltage fluctuation occurred


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4.4 How to Synchronize Generators of Onboard Ship?

Synchronizing of an incoming generator or alternator is very important before paralleling it

with another generator. The synchronizing of the generator is done with the help of

synchroscope or with three bulb method in case of emergency. It is of utmost importance that

before paralleling the generators the frequency and voltage of the generators need to be

matched. In this article we will describe the method for synchronizing generators on a ship.

There are two methods to synchronize generators on a ship – one is the normal and other is

the emergency method.

Synchroscope Method

Fig 13. Circuit Diagram of Synchroscope Method


The synchroscope consists of a small motor with coils on the two poles connected

across two phases. Let’s say it is connected in red and yellow phases of the

incoming machine and armature windings supplied from red and yellow phases

from the switchboard bus bars.


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The bus bar circuit consists of an inductance and resistance connected in parallel.

The inductor circuit has the delaying current effect by 90 degrees relative to

current in resistance.

These dual currents are fed into the synchroscope with the help of slip rings to the

armature windings which produces a rotating magnetic field.

The polarity of the poles will change alternatively in north/south direction with

changes in red and yellow phases of the incoming machine.

The rotating field will react with the poles by turning the rotor either in clockwise

or anticlockwise direction.

If the rotor is moving in clockwise direction this means that the incoming machine

is running faster than the bus bar and slower when running in anticlockwise

direction.

Generally, it is preferred to adjust the alternator speed slightly higher, which will

move the pointer on synchroscope is in clockwise direction.

The breaker is closed just before the pointer reaches 12 o clock position, at which

the incoming machine is in phase with the bus bar.

Emergency Synchronizing Lamps Method

This method is generally used when there is a failure of synchroscope. In case of failure a

standby method should be available to synchronize the alternator, and thus the emergency

lamp method is used.

Three lamps should be connected between three phases of the bus bar and the incoming

generator should be connected as shown in the diagram:


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Fig-4.4.2 Circuit Diagram of Emergency Synchronizing Lamps Method,


The lamps are connected only in this manner because if they are connected across,

the same phase lamps will go on and off together when the incoming machine is

out of phase with the switchboard.

In this method as per the diagram the two lamps will be bright and one lamp will

be dark when incoming machine is coming in phase with the bus bar.

The movement of these bright and dark lamps indicates whether the incoming

machine is running faster or slower.

For e.g. there is a moment when lamp A will be dark and lamp B & C will be

bright, similarly there will be instance when B is dark and others are bright and C

is dark and other two are bright. This example indicates that machine is running

fast and the movement of the lamps from dark and bright gives an clockwise

movement

Clockwise movement indicates fast and anti clockwise direction indicates slow

running of incoming generator.


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4.5 Why are Transformer and Alternator Ratings in kVA on Ships?

On ships, not only transformers, but also generators, protection devices etc., are mostly rated

in kVA. A motor does mechanical work and thus has mechanical output expressed in kW. A

transformer is a static device, which does not perform any mechanical work. But the main

functions are stepping down and stepping up of voltage ratings. Invariably, while stepping

up/down the voltage, it also steps down/up the current inversely. Thus the rating of a

transformer can only be expressed as a product of Volts and Amp. (V x I)

Amps Rating

The current flowing through the transformer can vary in power factor, from zero PF lead

(pure capacitive load) to zero PF lag (Pure inductive load) and is decided by the load

connected to the secondary. The conductor of the transformer winding is rated for a particular

current beyond which it will exceed the temperature for which its insulation is rated

irrespective of the load power factor.

Voltage Rating

The maximum voltage which the primary winding can be subjected to has also a maximum

limit. If the applied voltage to the primary winding exceeds the maximum rated value, then

this will cause magnetic saturation of the core leading to distorted output with higher iron

losses.

Thus considering both the above ratings, it is usual for transformers to be rated in VA. It can

further be understood as product of voltage & Current. But this does not mean that one can

apply a lower voltage and pass a higher current through the transformer contributing to the

rated VA value. The VA value is bounded individually by the rated voltage and rated current.

All electrical equipments in connection with generation, transmission, distribution of a.c.

power such as alternators, transformers, switchgear, cables etc are rated on k VA basis. We

know that, Cos φ = kW / k VA, or kVA = kW / Cos φ.

It is evident from the above equation that the larger the Power factor, the smaller is the k VA

requirement of the machinery. Therefore at low power factors, the K VA rating of the


page 40

equipment has to be made more, making the equipment larger and expensive. Thus kVA

rating is so important and it is assigned at the design stage itself.

4.6 Parallel Operation of Two Generators

When two synchronous generators are connected in parallel, they have an inherent tendency

to remain in step, on account of the changes produced in their armature currents by a

divergence of phase. Consider identical machines 1 and 2, Fig. 4.5.1 in parallel and working

on to the same load. With respect to the load, their emfs (electromotive forces) are normally

in phase: with respect to the local circuit formed by the two armature windings, however,

their emfs are in phase-opposition.

Suppose there to be no external load. If machine 1 for some reason accelerates, its e.m.f. will

draw ahead of that of machine 2. The resulting phase difference 2δ causes e.m.fs to lose

phase-opposition in the local circuit so that there is in effect a local e.m.f Es which will

circulate a current Is in the local circuit of the two armatures. The current Is flows in the

synchronous impedance of the two machines together, so that it lags by θ = arc tan(xs/r) ≈

90◦ on Es on account of the preponderance of reactance in ZsIs therefore flows out of

machine 1 nearly in phase with the e.m.f., and enters 2 in opposition to the e.m.f.

Consequently machine 1 produces a power Ps ≈ E1Is as a generator, and supplies it (I²R

losses excepted) to 2 as a synchronous motor. The synchronizing power Ps tends to retard the

faster machine 1 and accelerate the slower 2, pulling the two back into step. Within the limits

of maximum power, therefore, it is not possible to destroy the synchronous running of two

synchronous generators in parallel, for a divergence of their angular positions results in the

production of synchronizing power, which loads the forward machine and accelerates the

backward machine to return the two to synchronous running.

The development of synchronizing power depends on the fact that the armature impedance is

preponderating reactive. If it were not, the machines could not operate stably in parallel: for

the circulating current Is would be almost in phase quadrature with the generated e.m.f.’s,

and would not contribute any power to slow the faster or speed up the slower machine.


page 41

When both machines are equally loaded pn to an external circuit, the synchronizing power is

developed in the same way as on no load, the effect being to reduce the load of the slower

machine at the same time as that of the faster machine is increased.

The conditions are shown in Fig. 35, where I1, I2 are the equal load currents of the two

machines before the occurrence of phase displacement, and I′1, I′2 are the currents as

changed by the circulation of the synchronizing current Is.

Fig 15. Two Generators Set, Ref. M.V. BAGLAR KALLOL Fig 16. Circuit Diagram of Generators Set


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Fig-4.6.2 Vector Diagram of Parallel Operation, Ref. IIT, Madras, India

Fig-4.6.2 Generators Governor Characteristic

The argument above has been applied to identical machines. Actually, it is not essential for

them to be identical, nor to have neither equal excitations nor power supplies. In general, the

machines will have different synchronous impedance Zs1, Zs2; different e.m.f.’s E1 and E2

and different speed regulations.

The governors of prime movers are usually arranged so that a reduction of the speed of the

prime mover is necessary for the increase of the power developed. Unless the governor

speed/load characteristics are identical the machines can never share the total load in


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accordance with their ratings. The governor characteristics take the form shown in Fig. 4.5.2.

If the two are not the same, the load will be shared in accordance with the relative load values

at the running speed, for synchronous machines must necessarily run at identical speeds.

4.7 Principles of Power Factor

Definition of Power Factor

The cosine of angle between voltage and current in an a.c. circuit is known as Power Factor.

Power factor (PF) can be represented by the power triangle to show the relationship between

real powers in kilowatts (A), reactive power in kilovolt-amps reactive (B) and apparent power

in kilovolt-amps (C):

Fig-4.7.1 Power Triangle

(Ref. Books and Hand Work)

Real power performs actual work such as heating a burner element or illuminating an

incandescent bulb. Reactive power does not perform work but energizes magnetic fields in

motor windings or power supplies which create inductive loads. Apparent power is the result

of combining real power and reactive power. It measures the true load of an electrical

distribution system.

If real power and reactive power exist simultaneously, why can't we just add them together to

get apparent power? The reason is that purely reactive current (inductive load) is ninety

degrees out of phase with real current (resistive load). Thus, we use the power triangle

vectors to graphically represent this 90 degree relationship.


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Another way to look at this relationship is to compare the sine waves, or oscillograms, of

voltage and current for resistive and inductive loads. In a purely resistive load the current sine

wave and voltage sine wave are in sync with one another. The PF in this case is 100 percent

or unity.

Fig-4.7.2 Sine wave of Real Power & Reactive Power


In a purely inductive load the current sine wave lags 90 degrees behind the voltage sine wave.

The PF in this case would be zero.

In the real world there are no purely inductive loads because there is always some amount of

work being done by the device even if it is only the generation of heat. On the other hand,

purely resistive loads do exist in the real world such as a burner element or incandescent

bulb. When energized they have a PF of unity.

Impact of Low Power Factor

Low PF causes an inefficient utilization of electric power. In other words, you are using

more current to do the same amount of work when the PF is low. If we take the basic

equation for single phase power: Power = Voltage x Current x Power Factor

And solve for current we get: Current = Power__

Volts x PF

Voltage is assumed to remain constant in this example. If power is to be maintained, current

must go up when PF decreases. This increased requirement for current is where the electrical

inefficiency occurs.


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Let’s look at it graphically with two power triangles:

Fig-4.7.3 Low Power Factor Affective Triangle


In the example on the left the PF was measured at 70 percent. If our goal is to produce 100

kilowatts of real power we find that 141 KVA are required.

The power triangle on the right shows a PF of 95 percent. In this instance only 105 KVA are

required to produce the same amount of real power. Since voltage remains constant, the

current must increase by 35 percent to deliver the desired power when the PF is at 70 percent.

Power Factor Correction

Is there a way to correct this inefficient use of current? The answer is yes, by using power

factor correction capacitors. These capacitors are wired in parallel with the load. They may be

installed at the service entrance of the building or be dedicated to a specific device with a low

power factor.

PF correction capacitors are sized by the amount of KVAR they are able to correct. To

determine proper sizing, the PF for the building or the device must be measured under normal

operating conditions. A target PF such as 95 percent is selected. Using the Pythagorean

Theorem we can calculate the proper amount of correction as shown here:


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Fig-4.7.4 Power Factor Correction Triangle


If your home energy metering system can measure PF, take advantage of this information.

Check the PF on the larger motors in your home such as HVAC compressors and fans or a

pool pump if you have one. If it is below 80 percent you may want to consider power factor

correction capacitors for these motors.

Limit correction to only your larger motors as power factor correction capacitors can

introduce additional harmonic currents into your electrical system.

Harmonics can interfere with power line carrier communications which may affect your

home energy monitor system. Click here for more information about how PF and harmonics

interrelate.

Running motors with a higher PF has its benefits. Using more efficient power can lower

operating temperatures which extends bearing and motor life. It also reduces the load on your

transformer and decreases the amount of reactive currents circulating in your household

wiring although you probably won't see any direct savings on your electric bill.

This is because most residential utility rates only charge for kilowatt-hours (KWh), not

kilovolt-amp hours (KVAh) nor do they apply a specific penalty for low power factor. Check

the fine print on your power bill to be sure. This may change in the future as residential

customers add more inductive loads with electronic power supplies and home automation

equipment.

http://www.home-energy-metering.com/harmonics.html


page 47

4.8 Automatic Power Factor Improvement Controller (APFIC)

Introduction

The power factor controller is used for compensation of the reactive power of power systems.

The magnitude of the reactive power Q in the power system can be calculated from the

apparent power S and the active power P.

The power factor cosϕ is defined as the ratio between the active power and the apparent

power:

Consequently, the power factor controller must permanently monitor the value of the power

factor, which is used for calculating the reactive power component of the apparent power.

The power factor and the reactive power can be continuously calculated from the system

voltages and currents. Based on the need for compensation at any given time, one to four

capacitor banks can be switched on or off by the controller.


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Construction Diagram

Fig-4.8.1 Connection Diagram of PFI Controller

(Ref. Hand Drawing)

The automatic power factor controller connection diagram is shown in Fig-4.7.1. The

automatic power factor controller is consisting by capacitor bank, fuse, magnetic contactor,

module case circuit breaker and power factor controlling Metter.


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Operation

The power factor controller features a manual and an automatic operation mode. At manual

operation each capacitor bank can be switched on and off using the defined inputs of the

function block. This means that pulse-type signals are to be used for switching on and off,

which has to be considered in the configuration of the complete controller scheme. If a

capacitor bank is switched on, a logical signal 1 will appear on the associated output. When

this signal is switched off, the output will show a logical signal 0. To ensure that the

controller is always informed of the switch status of the capacitor banks a check-back signal

confirming the switch position must be fed back via the binary inputs. Fig-4.7.2 shows a

configuration example for a power factor controller managing five capacitor banks.

Fig-4.8.2. The photo was taken from BSC marine workshop while changing damaged fuse


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Compensation of reactive power is only required when the power system is in its operational

state. Therefore, the operability of the power factor controller can be made dependent on the

level of the system voltage. For this reason, the power factor controller should always include

an over voltage and under voltage function for monitoring the system voltage. If one of the

voltage limit pick-up values, either over voltage or under voltage, is exceeded and the

respective time delay has expired, all active capacitor banks will be switched off

immediately.

Time Setting

When the auxiliary supply is switched on, the power factor controller is blocked for the

initialization period and will not start operating until the initialization time has expired. The

same initialization time starts when the system voltage is recovering after a power system

fault, e.g. when the under voltage signal has been reset and the binary input DISCONNECT

is inactive. The initialization time is preferably given a value longer than the set blocking

time for the capacitor banks to discharge.

If, during an ongoing power factor control sequence, a capacitor bank is switched on to

compensate for the reactive power, transient phenomena will generally occur. This is why the

calculation of the power factor control must be delayed until most of the transient phenomena

have subsided. A dead time must be set for the power factor controller to bridge the transient

condition of the system. Further switching of the capacitor group will not be enabled until the

dead time has expired. However, a prerequisite for enabling switching of the capacitor group

is that the concerned capacitor bank is fully discharged.

Setting Example

Two capacitor banks of 6.36 µF each shall be applied to compensate the reactive power in a

10 kV power system. Consequently, each capacitor bank is able to compensate a reactive

power of , which equals the capacity of the smallest capacitor bank.

The maximum number of switching cycles shall be limited to 10,000, which is given by the

CB ratings provided by the manufacturer of the circuit breaker. The related setting parameter

can be seen in Fig-4.7.2.


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4.9 Emergency Power System of Onboard Ship

In case of the failure of the main power generation system on the ship, an emergency power

system or a standby system is also present. The emergency power supply ensures that the

essential machinery and system continues to operate the ship. Emergency power can be

supplied by batteries or an emergency generator or even both systems can be used.

Fig-4.9.1. Emergency Generator

(Ref. ABB Marine, 2012)

Rating of the emergency power supply should be made in such a way that it provides supply

to the essential systems of the ship such as

a) Steering gear system

b) Emergency bilge and fire p/p

c) Watertight doors.

d) Fire fighting system.

e) Ships navigation lights and emergency lights.

f) Communication and alarm system.

Emergency generator is normally located outside the machinery space of the ship. This is

done mainly to avoid those emergency situations wherein access to the engine room is not


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possible. A switch board in the emergency generator room supplies power to different

essential machinery.

4.10 Power Distribution System of Onboard Ship

The Power Distributed on board a ship needs to be supplied efficiently throughout the ship.

For this the power distribution system of the ship is used.

Fig-4.10. Power Distribution Board

(Ref. photo taken while working on board in M.V. Banglar Urmi)

A shipboard distribution system consists of different component for distribution and safe

operation of the system. They are:

Ship Generator consisting of prime mover and alternator. Main switch board which is

a metal enclosure taking power from the diesel generator and supplying it to different

machinery.

Bus Bars which acts as a carrier and allow transfer of load from one point to another.

Circuit breakers which act as a switch and in unsafe condition can be tripped to avoid

breakdown and accidents. Fuses as safety device for machinery.

Transformers to step up or step down the voltage. When supply is to be given to the

lighting system a step down transformer is used in the distribution system.

In a power distribution system, the voltage at which the system works is usually 440v.

There are some large installations where the voltage is as high as 6600v.


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For smaller supply fuse and miniature circuit breakers are used.

The distribution system is three wires and can be neutrally insulated or earthed.

5. Overview of Ship’s Power Utilization

5.1 Battery Charging System of Onboard Ship

Batteries are one of the energy sources available onboard vessels which are used in case of

blackout and emergency situations on board a ship. These batteries are used for low voltage

dc system like bridge navigational instruments and thus need to be kept charged to be used in

case of any need of temporary power.

Also, arrangement should be available on board to charge the batteries again after the use.

Moreover, the arrangement should be such that the batteries are able to be fully charged as

they gradually lose charge over the time.

The batteries can be charged with the help of dc power supply; however presently there are

no ships working on dc supply system and thus it is required to change the ac power into dc

to charge the batteries.

Fig-5.1.1 A trainee Engineer is changing the acid mix water in battery room in the ship

(Ref. The photo was taken from battery room while changing acid mix water)


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A simple circuit used for battery charging is shown below:-

Fig-5.1.2 Circuit Diagram of Bridge Rectifier

(Ref. Online Source)

For converting ac into dc several components are required as shown in the circuit diagram

above. First of all the ac is stepped down to the required voltage and then the AC is converted

to DC with the help of rectifier system which changes sinusoidal wave of ac to dc system.

The only problem in the above circuit is that there is no arrangement provided for

maintaining the charge, and the usage of same circuit will lead to overcharging and reduction

of the battery life. In order to avoid this, a slight modification is done in the same circuit and

an arrangement is provided to maintain the charges at the terminals. Also an arrangement to

connect automatically to low voltage dc system is provided in case of a power failure.

Fig-5.1.3 Connection diagram among battery, load and source

(Ref. Hand work)


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In normal circumstances the battery is charged using the full charge circuit and once the

battery is fully charged, the charges on the battery are maintained by the trickle charge

circuit.

Fig-5.1.4 Charging board while fault detection

(Ref. Photo was taken while Mr Kawsar is working in M.V. Banglar Urmi)

As it can be seen in the diagram, the batteries are in standby mode with the charging switches

C closed and the load switches L open. The positions of these switches are held with the help

of an electromagnetic coil against the spring tension. The electromagnetic coil gets its supply

from the main power source available on the ship. As soon as there is a loss of main power,

the electromagnetic coil loses its power and the batteries are connected to load switch L

which gets disconnected from the charging switch C.


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Once the power is available from the main system, the batteries are connected back to the

charging circuit again manually. Also there is a test switch provided to test the system as a

part of the routine checks.

5.2 Navigational Lights Used Onboard Ships

According to international navigational laws, navigation lights are the most important lights

fitted onboard a ship. They help in safe manoeuvring of the ship, preventing accidents and

collisions. As there are no signals or road-signs in the open sea, the navigational laws of ships

are demonstrated using these navigational lights, which are strategically arranged on ship.

They are differentiated on the basis of colours, visibility, range, angle and locations. The type

of navigational lights used depends on the size and type of the vessel and rules specified by

international conventions also known as rules of the road.

Types of Navigational Lights

Five separate specially designed navigational lights are fitted at different positions on the ship

as per the navigational rules. This gives easy identification of ships size, direction of travel,

anchorage of the ship. Following are the different colours and positions where these

navigation lights are fitted:

1. Foremast - Bright White

The foremast light has a horizontal arc range of 225 degrees.

2. Mainmast - Bright White

The mainmast light which is also known as all-round light has a horizontal arc visibility of

360 degrees.

3. Port side - Bright Red

The port side light horizontal arc visibility is 112.5 degrees.

4. Starboard side - Bright Green

The starboard side light horizontal arc visibility is 112.5 degrees

5. Stern of the ship - Bright White


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The aft or stern light horizontal arc visibility is 135 degrees.

Fig-5.2.1 Location of navigation lights, Ref. M.V. BANGLAR KALLOL (Left side photo)

Apart from these five mandatory navigation lights, two anchor lights are fitted forward and

aft and are bright white in colour. These lights are operated from the navigational bridge of

the ship.

The power for the navigational lights is supplied from a separate distribution board which has

no other supplies attached to it. This is done so that they cannot be put off by inadvertent

operation of a wrong switch.

For vessels of length more than 50 m, the visibility range of the mast head lights is 6 N.M

and all the other lights should be visible from a distance of 3 N.M. To achieve such visibility

special incandescent filament lamps are used and the normal power rating is of 65 KW. In

some cases 60 KW and 40 KW rating lamps are also permitted.

Due to the critical nature and essential safety requirement of navigational lights, they are

fitted in duplex manner at each position. Two separate lamps or a lamp holder with dual

fitting can also be used.

It is also to be noted that each light is separately supplied, switched, fused and monitored

from the navigational wheel house. The supply is usually of 220 V and is fed from essential

service section of main switch board and from emergency switch when there is a power


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failure. A changeover switch on the navigation light panel in wheel house selects the main or

standby power supply.

5.3 Different Types of Alarms of Onboard Ships

An emergency does not come with an alarm but an alarm can definitely help us to tackle an

emergency or to avoid an emergency situation efficiently and in the right way. Alarm systems

are installed all over the ship’s systems and machinery to notify the crew on board about the

dangerous situation that can arise on the ship.

Alarm on board ships are audible as well as visual to ensure that a person can at least listen to

the audible alarm when working in a area where seeing a visual alarm is not possible and vice

versa.

It is a normal practice in the international maritime industry to have alarm signal for a

particular warning similar in all the ships, no matter in which seas they are sailing or to which

company they belongs to. This commonness clearly helps the seafarer to know and

understand the type of warning or emergency well and help to tackle the situation faster.

The main alarms that are installed in the ship to give audio-visual warnings are as follows:

1) General Alarm: The general alarm on the ship is recognized by 7 short ringing of bell

followed by a long ring or 7 short blasts on the ship’s horn followed by one long blast. The

general alarm is sounded to make aware the crew on board that an emergency has occurred.

Fig-5.3.1 Device of Alarm

(Ref. marineinsight.com)


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2) Fire Alarm: A fire alarm is sounded as continuous ringing of ship’s electrical bell or

continuous sounding of ship’s horn.

3) Man Overboard Alarm: When a man falls overboard, the ship internal alarm bell

sounds 3 long rings and ship whistle will blow 3 long blasts to notify the crew on board and

the other ships in nearby vicinity.

4) Navigational Alarm: In the navigation bridge, most of the navigational equipments

and navigation lights are fitted with failure alarm. If any of these malfunctions, an alarm will

be sounded in an alarm panel displaying which system is malfunctioning.

5) Machinery Space Alarm: The machinery in the engine room has various safety

devices and alarms fitted for safe operation. If any one of these malfunctions, a common

engine room alarm is operated and the problem can be seen in the engine control room

control panel which will display the alarm.

6) Machinery Space CO2 Alarm: The machinery space is fitted with CO2 fixed with fire

extinguishing system whose audible and visual alarm is entirely different from machinery

space alarm and other alarm for easy reorganization.

7) Cargo Space CO2 Alarm: The cargo spaces of the ship are also fitted with fixed fire

fighting system which has a different alarm when operated.

8) Abandon Ship Alarm: When the emergency situation on board ship goes out of hands

and ship is no longer safe for crew on board ship. The master of the ship can give a verbal

Abandon ship order, but this alarm is never given in ship’s bell or whistle. The general alarm

is sounded and every body comes to the emergency muster station where the master or his

substitute (chief Officer) gives a verbal order to abandon ship.

9) Ship Security Alarm System: Most of the ocean going vessels are fitted with security

alert alarm system, which is a silent alarm system sounded in a pirate attack emergency. This

signal is connected with different coastal authorities all over the world via a global satellite

system to inform about the piracy.


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5.4 Single Phasing in Electrical Motors: Causes, Effects, and Protection Methods

For proper working of any 3 phase induction motor it must be connected to a 3 phase

alternating current (ac) power supply of rated voltage and load. Once these three phase

motors are started they will continue to run even if one of the three phase supply lines gets

disconnected. The loss of current through one of these phase supply is described as single

phasing.

Effect of Single Phasing

The following are the effects of single phasing:

1) Due to single phasing the current in the remaining two phases increase and it is

approximately 2.4 times the normal current value.

2) Single Phasing reduces the speed of the motor.

3) The motor becomes noisy and starts vibrating due to uneven torque produced in the motor.

4) If the motor is arranged for standby and automatic starting then the motor will not start,

and if the overload relay provided fails to function then the motor may burn.

5) The windings will melt due to overheating and can give a fatal shock to the personnel.

6) It may cause overloading of the generator.

Causes of Single Phasing

Fig-5.4.1 Circuit of Single Phasing (Ref. Online Source)


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Single Phasing is usually caused when:-

1) One of the three back up fuses blows (or fuse wire melts).

2) One of the contactor for motor is open circuited.

3) Single phasing might also be caused due to wrong setting of the protection devices

provided on the motor.

4) Contactors are coated due to oxidation hence not conducting.

5) Relay contacts may be damage or broken.

How to Protect Motor from Damage Due to Single Phasing?

All motors above 500 KW are to be provided with protection devices or equipments to

prevent any damage due to single phasing.

The rule stated above does not apply to motors of the steering gear system installed on the

ship. Only on the detection of the single phasing an alarm will be sounded; however, the

motor will not stop as it is essential for safety or propulsion of the ship.

The most commonly used protection devices for single phasing are:-

1) Electromagnetic Overload Device

Fig-5.4.2 Electromagnetic Overload Device (Ref. Online source)


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In this device all the three phases of the motor are fitted with an overload relay. If there is any

increase in the value of the current then this relay activates automatically and the motor trips.

This device works on the principle of electromagnetic effect produced due to the current.

As the current value increases, the electromagnet in the coil also increases which pulls the

relay and activates the trip relay and the motor is stopped.

The time delay is provided in this system because during starting the motor draws a lot of

current which can trip the motor.

2) Thermistors

Fig-5.4.3 Photo of Thermistor (Ref. Online source)

Thermistors are small thermal devices which are used together with an electromagnetic

overload relay. The thermistors are inserted in the three windings of the motor. Any increase

in the current will cause heating in the windings, which is detected by the thermistors that

send signals to the amplifier.

The amplifier is connected to electromagnetic relay. As soon as a signal is received from

thermistor about overheating, this amplifier increases the current value in the coil of

electromagnetic relay which activates the trip and the motor stops or trips.


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3) Bi-metal strip

Fig-5.4.4 Photo of Bi-metal strip (Ref. Online source)

In this method the bi metallic strip is placed in such a way that it detects the overheating in

the circuit. As soon as overheating is detected, this bimetallic strip tries to expand due to two

different metal used and because they have different coefficient of expansion. The strip tries

to bend towards the metal having high coefficient of expansion and finally completes the trip

circuit and the motor trips.

5.5 Maintenance of Electrical Relay on Ships Electrical Circuit

A relay is an important electromechanical safety device in ship’s electrical circuit and is

normally used to open the faulty circuit from the main supply when any kind of electrical

fault occurs. A relay is fitted in the Main and Emergency switch board of the ship as a

protective device.

Relay has to be kept operational and healthy at all times, else at the time of fault if it relay

does not operate properly, the whole system may suffer loss of power or damage. The most

common application of relays is for overload and short circuit protection.


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Fig-5.5.1 Photo of Electrical Rely (Ref. Online source)

A ship engineer or electrical officer has to make sure that relay is efficiently in operation and

all the maintenance is carried out on the same as per schedule or as per continuous

monitoring.

If during inspection, the relay is found out to be defective it must be replaced immediately

with a spare one.

A simple electromagnetic Relay is shown in the below diagram and it will get activated when

the magnetic effect of the iron core is sufficiently increased by the excess or high current in

the coil which will attract the iron armature held against the spring force to trip the circuit.

Fig-5.5.2 Circuit Diagram of Electrical Rely (Ref. Online source)


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A brief maintenance for relay is given as follows-

Checks to be carried out on relay contacts for damage due to arcing.

Polish the contact with emery paper to remove rust and deposits.

Check the closing linkage for free movement.

Check the continuity of the contacts with multimeter.

There are arc chutes provided to quench the arcing. Check for burnout of the same.

Check the tension of the spring.

Open circuit and short circuit test to be performed on the coil by multimeter.

Check the continuity of the trip circuit by multimeter.

Check tightness of the supply terminals.

5.6 How to Install Electronic Circuits on Ship?

With increase in modern technology and automation in ship’s machinery and operations,

electronic circuits like printed circuit board or PCB along with signal transducer and

transmission system are popularly used onboard. Since these are very small and vital circuits

they require proper location and precaution for their installation.

What is Printed Circuit Board (PCB)?

In ships, electronic system PCB plate or board is commonly used as it is compact in size and

easy to replace.

PCB is an electrical interconnection of different electronic components using tracks, signal

traces, conductive pathways etc., and the whole circuit is supported mechanically on a small

board.


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Fig-5.5.1 A Printed Circuit Board (Ref. Online source)

It is very important to properly locate the installation of electronic components as they are

prone to damage if there is excessive change in the surroundings.

Important points to be kept in mind while installing electronic system:

The electronic circuits get affected by change in temperature or heat so component

like transmitter should be installed in a place with good ventilation and with no gas or

steam leakage.

Cable connecting the electronic component must be installed over perforated plates

for good ventilation and should not lie on the hot surface.

The cable used must have proper insulation.

Circuits like PCB have more chance of getting damaged when exposed to high

temperature. Therefore, they are installed in Engine control room (ECR) and air

conditioning is provided in the control room to maintain the temperature of electronic

and electrical components.


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Fig-5.5.2 Location of Installation, where installed PCB (Ref. Online source)

While installing the electronic component, drier or silica gel packets are used in the

control box to avoid condensation of moisture over the circuit.

With moisture over the circuit due to humidity in the atmosphere, the electronic

component will behave erratic.

The box or cabinet used to install electronic circuit must be properly secured with the

surroundings to avoid vibration.

Vibration will cause loose or breaking of contacts.

All the components are to be tightly fitted in the cabinet as else loose fitting may lead

to vibration and hence breaking of contacts and components.

Electronic circuit’s component cable should not be in the vicinity of 440 v high

tension cable.

440 v cable produce electromagnetic field which will interact with the signal of the

electronic circuit and lead to wrong input or output.


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5.7 Procedure for Starting Emergency Steering System of Ship

What is Emergency Steering?

A ship consists of electromechanical steering gear unit which steers the vessel from one port

to other. Normally steering gear unit is 2 or 4 ram electro-hydraulically operated unit with

two or more hydraulic motor for the ram movement.

Fig-5.7.1 Steering Motor (Ref. marineinsight.com)

A situation can occur in which the remote control operation may fail to work and their can be

a sudden loss of steering control from the bridge. This can be due to sudden power failure,

any electrical fault in the system or the control system which includes faulty tele-motor or

servo motor which is used for transferring the signal from bridge to the steering unit.

To have control the steering of the ship at such emergency situation with manual measure

from within the steering gear room, an emergency steering system is used.


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Fig-5.7.2 Procedure of Steering Operation (Ref. marineinsight.com)

Procedure for Emergency Steering Operation

The following points should be followed for emergency steering operation.

- The procedure and diagram for operating emergency steering should be displayed in

steering gear room and bridge.

- Even in emergency situation we cannot turn the massive rudder by hand or any other

means, and that’s why a hydraulic motor is given a supply from the emergency generator

directly through emergency switch board (SOLAS regulation). It should also be displayed in

the steering room.

- Ensure a clear communication for emergency operation via VHF or ships telephone

system.

- Normally a switch is given in the power supply panel of steering gear for tele motor; switch

off the supply from the panel.

- Change the mode of operation by selecting the switch for the motor which is supplied

emergency power.

- There is a safety pin at the manual operation helms wheel so that during normal operation

the manual operation always remains in cut-off mode. Remove that pin.


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5.8 General Overview of Types of Pumps on Ship

A ship consists of various types of fluids moving inside different machinery and systems for

the purpose of cooling, heating, lubrication, and as fuels. These liquids are circulated by

different types of pumps, which can be independently driven by ship power supply or

attached to the machinery itself. All the systems on board ship require proper operational and

compatible pump and pumping system so that ship can run on its voyage smoothly.

The selection of a type of pump for a system depends on the characteristics of the fluid to be

pumped or circulated. Characteristics such as viscosity, density, surface tension and

compressibility, along with characteristics of the system such as require rate of fluid, head to

which the fluid is to be pumped, temperature encountered in the system, and pressure tackled

by the fluid in the system, are taken into account.

Types of Pumps

The pumps used on board are broadly classified into two types: (a) Positive Displacement

Pump and (b) Dynamic pressure pumps

(a) Positive Displacement Pump

Fig-5.8.1 Positive Displacement Pump (Ref. marineinsight.com)

Positive displacement pumps are self priming pumps and are normally used as priming

devices.


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They consist of one or more chamber, depending upon the construction, and the

chambers are alternatively filled and emptied.

The positive displacement pumps are normally used where the discharge rate is small

to medium.

They are popularly used where the viscosity of the fluid is high.

They are generally used to produce high pressure in the pumping system.

(b) Dynamic pressure pumps:

Fig-5.8.2 Dynamic pressure pumps (Ref. marineinsight.com)

Dynamic pressure pump functions are:

In dynamic pressure pump, during pumping action, tangential force is imparted which

accelerates the fluid normally by rotation of impeller.

Some systems which contain dynamic pump may require positive displacement pump

for priming.

They are normally used for moderate to high discharge rate.

The pressure differential range for this type of pumps is in a range of low to moderate.

They are popularly used in a system where low viscosity fluids are used.

These broad classification of pumps are further differentiates by their constructional

properties and popularity of usage onboard ship;


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Positive Displacement pump:

Reciprocating Pump

Screw pump

Gear pump

Piston pump

Ram type pump

Vane pump

Dynamic pressure pumps:

Centrifugal pumps

Axial flow pumps

Submersible pump

Centrifugal-axial (mixed) pump.

5.9 The Basics of Air Compressor of Onboard Ship

Compressor is one such device which is used for several purposes on a ship. As the main aim

of the compressor, as the name suggests, is to compress air or any fluid in order to reduce its

volume. Some of the main applications of compressors are main air compressor, deck air

compressor, AC compressor and refrigeration compressor. In this article we will learn about

air compressors and its types.

Types of Air Compressors

There are mainly four types of compressors:

1) Centrifugal compressor; 2) Rotary vane compressor

3) Rotary screw compressor; 4) Reciprocating air compressor.


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Uses of Air Compressor on Ship:

On board a ship, compressed air is used for several purposes. On the basis of application,

different air compressors are kept for a particular usage. Normally, air compressors on board

ships are:

-main air compressor,

-topping up compressor

-deck air compressor

-Emergency air compressor

Main air compressor

Fig-5.9.1 Main air compressor (Ref. marineinsight.com)

Main air compressor is used for supplying high pressurised air for starting of main and

auxiliary engines. The pressurised air generated by the air compressor is stored in air storage

bottle. These are high capacity compressors and the air pressure that is required from these

compressors to start the main engine is 30 bars.

Control air is also supplied from air bottle through a pressure reducing valve and a control air

filter. Normally they are twice in number and can be more than that for redundancy.


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Topping up compressor

Topping up compressor takes up the lead to cover up for the leakage in the system. This

means that as soon as the air pressure in the system goes below a particular level, the topping

up compressor replenished the system with pressurized air.

Deck air compressor

Deck air compressor is used for deck use and as service air compressor and might have a

separate service air bottle for the same. These are lower capacity pressure compressors as

pressure required for service air is in between the range of 6 to 8 bar.

Emergency air compressor

Emergency air compressor is used for starting auxiliary engine at the time of an emergency or

when the main air compressor has failed for filling up the main air receiver. This type of

compressor can be motor driven or engine driven. If motor driven, it should be supplied from

emergency source of power.

5.10 Construction and Working of Ships Refrigeration Plant

The refrigeration plants on merchant vessels play a vital part in carrying refrigerated cargo

and provisions for the crew on board. In reefer ships, the temperature of the perishable or

temperature sensitive cargo such as food, chemical, or liquefied gas, is controlled by the

refrigeration plant of the ship. The same plant or a smaller unit can be used for maintaining

the temperature of different provision rooms carrying food stuffs for crew members.

Main Components of Refrigeration plants

Any refrigeration unit works with different components inline to each other in series. The

main components are:

1. Compressor: Reciprocating single or two stage compressor is commonly used for

compressing and supplying the refrigerant to the system.


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2. Condenser: Shell and tube type condenser is used to cool down the refrigerant in the

system.

3. Receiver: The cooled refrigerant is supplied to the receiver, which is also used to drain out

the refrigerant from the system for maintenance purpose.

4. Drier: The drier connected in the system consists of silica gel to remove any moisture

from the refrigerant

5. Solenoids: Different solenoid valves are used to control the flow of refrigerant into the

hold or room. Master solenoid is provided in the main line and other solenoid is present in all

individual cargo hold or rooms.

6. Expansion valve: An Expansion valve regulates the refrigerants to maintain the correct

hold or room temperature.

7. Evaporator unit: The evaporator unit act as a heat exchanger to cool down the hold or

room area by transferring heat to the refrigerant.

8. Control unit: The control unit consist of different safety and operating circuits for safe

operation of the refer plant.

Working of Ship’s Refrigeration Plant

Fig-5.10.1 Refrigeration Plant (Ref. marineinsight.com)


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The compressor acting as a circulation pump for refrigerant has two safety cut-outs- Low

pressure (LP) and High Pressure (HP) cut outs. When the pressure on the suction side drops

below the set valve, the control unit stops the compressor and when the pressure on the

discharge side shoots up, the compressor trips.

LP or low pressure cut out is controlled automatically i.e. when the suction pressure drops,

the compressor stops and when the suction pressure rises again, the control system starts the

compressor. HP or high pressure cut out is provided with manually re-set

The hot compressed liquid is passed to a receiver through a condenser to cool it down. The

receiver can be used to collect the refrigerant when any major repair work has to be

performed.

The master solenoid is fitted after the receiver, which is controlled by the control unit. In case

of sudden stoppage of compressor, the master solenoid also closes, avoiding the flooding of

evaporator with refrigerant liquid.

The room or hold solenoid and thermostatic valve regulate the flow of the refrigerant in to the

room to maintain the temperature of the room. For this, the expansion valve is controlled by a

diaphragm movement due to the pressure variation which is operated by the bulb sensor filled

with expandable fluid fitted at the evaporator outlet.

The thermostatic expansion valve supplies the correct amount of refrigerants to evaporators

where the refrigerants takes up the heat from the room and boils off into vapours resulting in

temperature drop for that room.

This is how temperature is maintained in the refrigeration plant of the ship.

5.11 How to Find an Earth Fault On board Ships?

Earth fault is considered very critical on board a ship. Some ships which operate at 440 V do

not have any trip devices attached for a single earth fault. However when the operating

voltage exceeds 3000V, it is mandatory to have a protection system which isolates when a

machinery suffers an earth fault.


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How to find out an Earth Fault?

The seriousness of the action to be taken on an Earth Fault depends on the part of the

electrical system it affects. Conventional ships which operate on 3 Phase, 440V, have earth

fault indicators installed on all three phases. Any earth fault on a 440V system is considered

to be a serious trouble and immediate action is required to identify the faulty circuit. Any

earth fault on 220V or any low voltage lighting circuit can be considered as important but

need not require immediate attention. However, attention should be paid at the next earliest

opportunity.

Fig-5.11.1 Finding Earth Fault on 440V circuit (Ref. ABB Marine)

Whenever there is an earth fault alarm, immediately inform to electrical officer (if he is on

board). First action is to check the trueness of the alarm. Usually there will be a test button

which when pressed, resets the alarm and rechecks the condition of the earth fault.

If the ship is having IAS (Integrated Automation System), check on the computer in the list

of events after which the alarm has activated. If IAS facility is not available, there is only one

option of isolating each and every machinery in the 440 V circuit and check whether the earth

fault indication returns back to normal.


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Fig-5.11.2 Earth Fault Detecting on 440V circuit (Ref. ABB Marine)

Isolation of all machinery, which operates on 440V, is not always possible. Certain critical

equipment like steering gear and lubricating oil pumps cannot be isolated for when the ship is

underway. However changeover can be done from running machinery to the standby one and

thus the earth fault can be found.

Finding Earth Fault on 220V Circuit

Finding an Earth Fault on a 220V circuit is comparatively difficult than a 440V circuit. The

main reason being the lighting circuits found all round the vessel. However, any earth fault

alarm with respect to a 220V circuit is usually treated as important but not an emergency.

When a 220V earth fault alarm sounds, as said earlier, the trueness of the alarm is checked by

pressing the test button and then investigation can be started on each and every 220V circuit.


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5.12 How to Minimize the Risks of an Electrical Shock of Onboard Ship?

If you are new to a ship, the first few days might leave you confused, lost, and extremely

apprehensive as to how are you going to spend the rest of your days of your contract on the

ship safely without confronting any accidents. The huge matrix of pipes, the complex

machinery, and the massive bunch of wires which runs without any restrictions in different

directions might leave you a bit messed up in your mind. It is during this vulnerable mindset,

you can come across the worst accident that has happened to you.

When we talk about accidents on a ship, an electrical shock is the worst of all kinds.

Electrical wires and connections are present everywhere on a ship and it is important to

escape them to prevent yourself and others from getting a major electrical shock. Moreover, it

is said that a person on board a ship gets an electrical shock mainly due to its negligence and

unawareness. In this article we will learn as to how you can save yourself and others from an

electrical shock on board a ship. Also find out what all precautions you should take to

minimize the risk of an electrical shock on board.

Steps to Minimize the Risk of an Electrical Shock On board

1) Start with the first round of the day; check all electrical motors, wiring, and switches,

for abnormal sounds, variation in temperatures, and loose connections.

2) Ensure that all electrical connections are inside the panel box so that no one can touch

them accidently.

3) In accommodation area multiple socket plugs shouldn’t be used.

4) Turn off the breaker before starting any work on an electrical system.

5) Use ply card and notice board as much as possible to inform others about the ongoing

work to avoid accidental starts.

6) Double check the electrical tools like portable drills for any loose wires before

attempting any job.


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6. Overview of Ship’s Communication System

6.1 Overview of Radar

Historical Background of Radar

As early as 1886, Heinrich Hertz showed that radio waves could be reflected from solid

objects. In 1895, Alexander Popov, a physics instructor at the Imperial Russian Navy School

in Kronstadt, developed an apparatus using a coherer tube for detecting distant lightning

strikes. The next year, he added a spark-gap transmitter. In 1897, while testing this equipment

for communicating between two ships in the Baltic Sea, he took note of an interference beat

caused by the passage of a third vessel. In his report, Popov wrote that this phenomenon

might be used for detecting objects, but he did nothing more with this observation.

The German Christian Huelsmeyer was the first to use radio waves to detect "the presence of

distant metallic objects". In 1904 he demonstrated the feasibility of detecting a ship in dense

fog, but not its distance from the transmitter. He obtained a patent for his detection device in

April 1904 and later a patent for a related amendment for determining the distance to the

ship. He also got a British patent on September 23, 1904 for the first full radar application,

which he called Telemobiloscope.

Definition of Radar

Radar is an object-detection system which uses radio waves to determine the range, altitude,

direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided

missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits

pulses of radio waves or microwaves which bounce off any object in their path. The object

returns a tiny part of the wave's energy to a dish or antenna which is usually located at the

same site as the transmitter.

Radar was secretly developed by several nations before and during World War II. The term

RADAR was coined in 1941 by the United States Navy as an acronym for Radio Detection

And Ranging. The term radar has since entered English and other languages as the common

noun radar, losing all capitalization.


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Applications of Radar

Fig-6.1.1 Commercial marine radar antenna (Ref. M.V. BANGLAR URMI)

Marine radars are used to measure the bearing and distance of ships to prevent collision with

other ships, to navigate, and to fix their position at sea when within range of shore or other

fixed references such as islands, buoys, and lightships. In port or in harbour, vessel traffic

service radar systems are used to monitor and regulate ship movements in busy waters. Police

forces use radar guns to monitor vehicle speeds on the roads.

Principles of Radar

A radar system has a transmitter that emits radio waves called radar signals in

predetermined directions. When these come into contact with an object they are usually

reflected or scattered in many directions. Radar signals are reflected especially well by

materials of considerable electrical conductivity especially by most metals, by seawater, by

wet land, and by wetlands. Some of these make the use of radar altimeters possible. The radar

signals that are reflected back towards the transmitter are the desirable ones that make radar

work. If the object is moving either toward or away from the transmitter, there is a slight

equivalent change in the frequency of the radio waves, caused by the Doppler Effect.


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Operation of the Marine Radar

Fig-6.1.2 An Electrical Engineer is operating a radar (Left), Display of Radar Screen (Right)

(Ref. The photo was taken during operation in the ship)

The ship radar has a screen that displays all the objects that are present in the immediate

range of the radar. Since all the objects are clearly visible on the screen, navigating and

monitoring the position of the ship becomes really feasible

The operation of the marine radars can be explained as follows:

There is an antenna on the top of the radar that continuously rotates and flashes.

The flashes actually are frequency beams that are transmitted from the radar to find

out whether there any objects present in the path of the ship.

The frequency and the time taken by the flashes to return (reflections) to the radar

receiver of the ship helps to find out whether the route of the boat can be continued

with or not.

On the display screen, the reflections can be seen so that identifying the actual

distance of the objects can be even easier.


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Signal Processing of Radar

Fig-6.1.3 Over all connection diagram of radar signal processing

(Ref. ABB Marine from Online)

One way to measure the distance to an object is to transmit a short pulse of radio signal

(electromagnetic radiation) and measure the time it takes for the reflection to return. The

distance is one-half the product of the round trip time (because the signal has to travel to the

target and then back to the receiver) and the speed of the signal. Since radio waves travel at

the speed of light, accurate distance measurement requires high-performance electronics. In

most cases, the receiver does not detect the return while the signal is being transmitted.

Through the use of a duplexer, the radar switches between transmitting and receiving at a

predetermined rate. A similar effect imposes a maximum range as well. In order to maximize

range, longer times between pulses should be used, referred to as a pulse repetition time, or

its reciprocal, pulse repetition frequency.


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These two effects tend to be at odds with each other, and it is not easy to combine both good

short range and good long range in single radar. This is because the short pulses needed for a

good minimum range broadcast have less total energy, making the returns much smaller and

the target harder to detect. This could be offset by using more pulses, but this would shorten

the maximum range. So, each radar is uses a particular type of signal. Long-range radars tend

to use long pulses with long delays between them, and short range radars use smaller pulses

with less time between them. As electronics have improved many types of radar now can

change their pulse repetition frequency, thereby changing their range. The newest radars fire

two pulses during one cell, one for short range (10 km /6.2 miles) and a separate signal for

longer ranges (100 km /62 miles).

Advantages of Radar

With the help of ship radar, accidents can be prevented in the oceanic area. However, even

while the ships are docked in the port, with the help of these radars, the coast guard and the

other authorities can use them to monitor the traffic in the small radar range.

The most important point about marine radars is that the screens used to view the position of

the objects are either LED screens or monochrome screens. With such perfect screens, the

clarity of the objects is highlighted even further. Also since these screens are water-proof

there is no threat of interruption to the ship radar system in times of rough weather.

The tracking ship system has further been developed to include even boats. This means that

even boat owners can be assured of their vessel’s safety while on the water.

One major advantage of the marine radars is that the power and electricity consumption by

them is far too less. This means that the marine radars are not just user-friendly but also help

the ship owner to regulate the cost of power and electricity.

Radar has been a major instrument to help marine navigation since the past six decades. Over

the years, the radar technology has developed to include not just aircrafts but ships as well.

Marine travel and safety, thus has become very feasible.


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6.2 Overview of LRIT

Definition of LRIT

The Long-Range Identification and Tracking (LRIT) system provides for the global

identification and tracking of ships.

The obligations of ships to transmit LRIT information and the rights and obligations of

SOLAS Contracting Governments and of Search and rescue services to receive LRIT

information are established in regulation V/19-1 of the 1974 SOLAS Convention.

Applications of LRIT

The LRIT system consists of the ship borne, LRIT information transmitting equipment, the

Communication Service Provider(s), the Application Service Provider(s), the LRIT Data

Centre(s), including any related Vessel Monitoring System(s), the LRIT Data Distribution

Plan and the International LRIT Data Exchange. Certain aspects of the performance of the

LRIT system are reviewed or audited by the LRIT Coordinator acting on behalf of all

SOLAS Contracting Governments.

LRIT information is provided to Contracting Governments to the 1974 SOLAS Convention

and Search and rescue services entitled to receive the information, upon request, through a

system of National, Regional and Cooperative LRIT Data Centres using the International

LRIT Data Exchange.

Each Administration should provide to the LRIT Data Centre it has selected, a list of the

ships entitled to fly its flag, which are required to transmit LRIT information, together with

other salient details and should update, without undue delay, such lists as and when changes

occur. Ships should only transmit the LRIT information to the LRIT Data Centre selected by

their Administration.

Principles of LRIT

The LRIT system involves a request and response process, with various components linked

together. Ship LRIT equipment must be capable of being configured to transmit information


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as an Automatic Position Report (APR). The APR includes the identity of the ship, the

position of the ship and the date and time of the position report.

In addition, the equipment must be able to respond to poll requests for an on-demand position

report and be able to immediately respond to instructions to modify the APR interval to a

frequency of a maximum of one report every 15 minutes. The equipment requirement may be

met through existing GMDSS Inmarsat equipment, or it may be necessary to install

equipment designed to be LRIT compliant – testing has been designed to ensure whatever

equipment is used will work within the overall LRIT system. Ship owners should be aware of

the Application Service Provider (ASP) that their flag has recognized or authorized to

undertake testing.

Fig-6.2.1 Data exchange system of LRIT (Ref. ABB Marine)

Operational Concept of LRIT

LRIT is a maritime domain awareness (MDA) initiative to enhance maritime safety, security

and protect the marine environment. LRIT allows Member States to receive position reports


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from vessels operating under their flag, vessels seeking entry to a port within their territory,

or vessels operating in proximity to the State’s coastline. There are two aspects to LRIT:

1) The ‘reporting’ aspect where vessels to which LRIT applies report their identity and

position, with a date/time stamp, every six hours (four times per day).

2) The ‘receiving’ aspect where coastal States can purchase reports when vessels are within

1,000 nautical miles, or where port States can purchase reports when vessels seek entry

to a port at a pre-determined distance or time from that port (up to 96 hours pre-entry).

Put in simple terms, LRIT is a collection and distribution system for basic information on

vessels, and applies to the following ships engaged on international voyages:

All passenger ships including high speed craft;

Cargo ships, including high speed craft of 300 gross tonnage and above; and

Mobile off shore drilling units.

Ships operating exclusively in GMDSS Sea Area A1 and fitted with an Automatic

Identification System (AIS) are exempt from LRIT requirements, while ships operating in

Sea Areas A2, A3 and A4 are required to be fitted with a system to automatically transmit

LRIT information in accordance with SOLAS Regulations1.

Vessels limited to domestic voyages – for example coastal trading vessels that only travel

between Australian ports, do not reflect the definition of ‘International Voyage’ and are not

required to report to LRIT. However, if a vessel that normally does coastal trading proceeds

to an international port for any reason, including dry dock, they will need to either fully

comply with the LRIT requirements or apply for an exemption for the duration of the

international voyage.


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6.3 Electronics Navigation

Fig-6.3.1 Eleectronics Navigation

(Ref. ABB Marine)

The aim is to develop a strategic vision for e-navigation, to integrate existing and new

navigational tools, in particular electronic tools, in an all-embracing system that will

contribute to enhanced navigational safety (with all the positive repercussions this will have

on maritime safety overall and environmental protection) while simultaneously reducing the

burden on the navigator. As the basic technology for such an innovative step is already

available, the challenge lies in ensuring the availability of all the other components of the

system, including electronic navigational charts, and in using it effectively in order to

simplify, to the benefit of the mariner, the display of the occasional local navigational

environment. E-navigation would thus incorporate new technologies in a structured way and

ensure that their use is compliant with the various navigational communication technologies

and services that are already available, providing an overarching, accurate, secure and cost-

effective system with the potential to provide global coverage for ships of all sizes.


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6.4 AIS Transponders

Automatic identification systems (AISs) are designed to be capable of providing information

about the ship to other ships and to coastal authorities automatically.

The AIS shipborne equipment, like any other shipborne transceiver operating in the VHF

maritime band, may cause interference to a ship.s VHF radiotelephone. Because AIS is a

digital system, this interference may occur as a periodic (e.g. every 20 s) soft clicking sound

on a ship.s radiotelephone. This affect may become more noticeable when the VHF

radiotelephone antenna is located near the AIS VHF antenna and when the radiotelephone is

operating on channels near the AIS operating channels (e.g. channels 27, 28 and 86).

Attention should be paid to the location and installation of different antennas in order to

obtain the best possible efficiency. Special attention should be paid to the installation of

mandatory antennas like the AIS antennas.

Location of the mandatory AIS VHF antenna should be carefully considered. Digital

communication is more sensitive than analogue/voice communication to interference created

by reflections in obstructions like masts and booms. It may be necessary to relocate the VHF

radiotelephone antenna to minimize interference effects.

6.5 Marine VHF Radio

Marine VHF radio is used by all large ships and most seagoing small craft to summon rescue

services and communicate with harbors, locks, bridges and marinas. A marine VHF set

combines a transmitter and receiver and only operates on standard, international frequencies

specified for marine use.


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6.6 Ship’s Voyage Data Recorders (SVDR)

Like the black boxes carried on aircraft, VDRs enable accident investigators to review

procedures and instructions in the moments before an incident and help to identify the cause

of any accident.

Fig-6.6.1 Location of SVDR (Ref. marineinsight.com, 2012)

Performance standards for VDRs were adopted in 1997 and give details on data to be

recorded and VDR specifications. They state that the VDR should continuously maintain

sequential records of pre-selected data items relating to status and output of the ship's

equipment and command and control of the ship. The VDR should be installed in a protective

capsule that is brightly coloured and fitted with an appropriate device to aid location. It

should be entirely automatic in normal operation.

Recovery of the VDR information should be undertaken as soon as possible after an accident

in order to best preserve the relevant evidence for use by both the accident investigators and

the ship owner.

It has recently been reported by some marine incident investigators that some ships’ crews

are not sufficiently well familiarised with the recording system of the VDR, and consequently

the information in some cases was not saved, and was then overwritten or the copy was

damaged.


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7. Conclusions

This report discussed a new automated intelligent reconfiguration/restoration system for

shipboard electrical systems. The system automatically assesses a shipboard power system's

fault conditions for damage, identifies catastrophic failure, localizes the affected cables and

loads, and then reconfigures and restores power to vital loads and as many of the remaining

loads as possible. This new technique makes the system more reliable in providing

continuous electric supply and reduces the manpower required to operate the system under

faulted conditions.

This Report contains the power generation, communication system and Troubleshooting of

different types of equipment in ship’s engine room. During four months of my practicum

session, I have learned practical knowledge about how to power generate in marine vessels

and how to communicate between ship’s and shore.

I am fortunate enough for getting the opportunity of doing my internship in well developed

organization. During the internship period I have got warm co-operation from all personnel

involved from operational, management and administration. Finally I would like to thank all

of them.

8. Recommendations

After enough hard working with ship electrical and electronics systems and adequate research

on this discipline and thorough knowledge of ship electrical and electronics and their

appropriate utilization, the following recommendations can be undertaken with respect to:

There is a great chance for the electrical engineering student to work with marine

vessel. As there are so many sophisticated and modern electrical equipments in the

marine vessel, student can learn a lot and can be an expert in specific area. The

knowledge on marine vessel can help them to get marine associated job.

Power loss of the different motor or generator can be reduced by close inspection in

marine vessel. Fault of the different electrical machine can be identified by testing

them time to time. The knowledge on vessel’s complex electrical system will help a


page 92

person to understand similar electrical system easily. There is a great chance for an

electrical engineer to develop his skill and expertise.

Beside engineering experience, there is an opportunity of learning vessel’s sailing and

international roaming. There is an immense scope of sharing engineering views and

ideas with the engineers of different countries.

There is a great opportunity to strengthen the basic electrical knowledge. Getting a

chance of a trainee electrical engineer, it is possible to gain work in the same field and

can be further improved the skill, knowledge and expertise in this area to expand the

electrical and electronics engineering field in the global context.

9. References

9.1 Online sources

[1]. www.bsc.gov.bd

[2]. www.marineinsight.com

[3]. www.abb.com/marine

[4]. www.imo.org

[5]. www.google.com

[6]. www.answer.com

[7]. www.wikipedia.com

[8]. www.woodward.com/power

[9]. www.iacs.org.uk

[10]. www.hse.gov.uk

[11]. http://www.need.org/needpdf/infobook_activities/PriInfo/SourcesP.pdf

[12]. http://www.shipspotting.com/gallery/photo.php?lid=1282183

[13]. http://www.banglapedia.org/httpdocs/HT/B_0248.HTM

9.2 Bibliography

[1]. Adnanes, A.K (2003), Maritime Electrical Installations and Diesel Electric

Propulsion, Tutorial Report/Textbook, ABB Marine AS, Oslo, Norway

[2]. Adnanes, A.K (2004) Maritime Electrical Installations Lecture Slides, Marine

Control Systems, Marine Cybernetics, Department of Marine Technology,

NTNU, Trondheim, Norway,

http://www.bsc.gov.bd/

http://www.marineinsight.com/

http://www.abb.com/marine

http://www.imo.org/

http://www.google.com/

http://www.answer.com/

http://www.wikipedia.com/

http://www.woodward.com/power

http://www.iacs.org.uk/

http://www.hse.gov.uk/

http://www.need.org/needpdf/infobook_activities/PriInfo/SourcesP.pdf

http://www.shipspotting.com/gallery/photo.php?lid=1282183

http://www.banglapedia.org/httpdocs/HT/B_0248.HTM


page 93

[3]. Adnanes, A.K., Sørensen, A.J and Hackman, T (1997), Essential

Characteristics of Electrical Propulsion and Thruster Drives in DP Vessels,

DYNAMIC POSITIONING CONFERENCE

[4]. Banglapedia – National Encyclopedia of Bangladesh.

[5]. Direct and Alternating Current Machinery- Rosenblatt Friedman

[6]. Daniels, A.R. (1985). Introduction to Electrical Machines. Macmillan.

ISBN 0-333-19627

[7]. Flanagan, W (1993). Handbook of Transformer Design and Applications.

McGraw-Hill. ISBN 0-0702-1291-0.

[8]. Gottlieb, I (1998). Practical Transformer Handbook. Elsevier. ISBN 0-7506-

3992-X.

[9]. Harlow, James (2004). Electric Power Transformer Engineering. CRC Press.

ISBN 0-8493-1704-5.

[10]. Heathcote, M (1998). J & P Transformer Book, Twelfth edition. Newnes.

ISBN 0-7506-1158-8.

[11]. Hindmarsh, J (1977). Electrical Machines and their Applications, 4th edition.

Exeter: Pergammon. ISBN 0-08-030573-3.

[12]. IACS (2004), Requirements Concerning Machinery Installation, International

Association of Classification Societies,

[13]. Introduction to Electrical Engineering- V.K. Mehta

[14]. Kulkarni, S.V. & Khaparde, S.A. (2004). Transformer Engineering: design and

practice. CRC Press. ISBN 0-8247-5653-3.

[15]. Marine Electrical Equipment and Practice- H.D.McGeorge, C.Eng.,F.I.Mar.E.

[16]. May, J.J and Foss H (2000), Power Management System for the "Deepwater

Horizon" a Dynamically Positioned All Weather Semisubmersible, Dynamic

Positioning Conference,

[17]. Practical Marine Electrical Knowledge- D. T. Hall.

[18]. Marine Electrotechnology and Electronics- Vikram Gokhala, N. Nanda.

[19]. Marine Electrical Practice- G.O. Watson

[20]. McLaren, P (1984). Elementary Electric Power and Machines. Ellis Horwood.

ISBN 0-4702-0057-X.

[21]. McLyman, C.W (2004). Transformer and Inductor Design Handbook. CRC.

ISBN 0-8247-5393-3.

[22]. Pansini, A (1999). Electrical Transformers and Power Equipment. CRC Press.

p. 23. ISBN 0-8817-3311-3.

[23]. Power Plant Engineering- G.R. Nagpal

[24]. Principles of Power system- V.K.Mehta, Pohit Mehta.

[25]. Ryan, H.M. (2004). High Voltage Engineering and Testing. CRC Press.

ISBN 0-8529-6775


page 94

[26]. Say, M.G. (1983). Alternating Current Machines, Fifth Edition. London:

Pitman. ISBN 0-273-01969-4.

[27]. Theraja, B.L. and Theraja, A.K (undated). Text Book of Electrical Technology

[28]. Winders, J (2002). Power Transformer Principles and Applications. CRC.

ISBN 0-8247-0766-4,

[29]. Woodward Co (2004), Governing Fundamentals and Power Management.

10. Appendix

10.1 List of Acronyms/Abbreviations used in the report

AC Alternating Current

AIS Automatic Identification System

AMSA Australian Maritime Safety Authority

ASP Application Service Provider

AVR Automatic Voltage Regulator

BMA Bangladesh Marine Academy

BMTI Bangladesh Maritime Training Institute

BSC Bangladesh Shipping Corporation

BSFC Break Specific Fuel Consumption

CSP Communication Service Provider

CT Current Transformer

DB Distribution Board

DC Direct Current

DDP Data Distribution Plan

DP Dynamic Positioning

EFA Elementary First Aid

FAT Factory Acceptance Test

FIRE Find Inform Restricted Extinguish

FPFF Fire Prevention & Fire Fighting

GISIS Global Integrated Shipping Information System


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GMDSS Global Maritime Distress and Safety System

HP Horse Power

HT High Tension

HVAC High Voltage Alternating Current

HVCB High Voltage Circuit Breakers

HVDC High Voltage Direct Current

HVPS High Voltage Power Supply

IAPH International Association of Ports & Harbors

IDC International Data Centre

IDE International Data Exchange

IIMT International Institute of Maritime Technology

IMO International Maritime Organisation

IMSO International Mobile Satellite Organization

IP Internet Protocol

ISM International Safety Management

ISPS International Ship and Port Facility Security

ISSC International Ship Security Certificate

KVA Kilo Volt Ampere

KVAR Kilo Volt Ampere Reactance

KW Kilo Watts

KWH Kilo Watts Hour

LES Land Earth Station

LF Low Frequency

LRIT Long Range Identification and Tracking

LT Low Tension

LVCB Low Voltage Circuit Breakers

MCB Miniature Circuit Breaker

MCCB Molded Case Circuit Breaker

MDB Main Distribution Board

MIST Maritime Institute of Science and Technology


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MMSI Maritime Mobile Service Identity

MV Motor Vessel

MVCB Medium Voltage Circuit Breakers

MW Mega Watts

NMI National Maritime Institution

PF Power Factor

PFIP Power Factor Improvement Plant

PKI Public Key Infrastructure

PLC Programmable Logic Controller

PMMC Permanent Magnet Moving Coil

PMS Power Management System

PSSR Personal Safety & Social Responsibilities

PST Personal Survival Techniques

PT Potential Transformer

RADAR Radio Detection and Ranging

RCA Redundancy and Criticality Assessment

RFP Request for Proposal

RPM Revolution Per Minute

SAR Search and Rescue

SMC Safety Management Certificate

SMS Safety Management System

SOAP Simple Object Access Protocol

SOLAS International Convention for the Safety of Life at Sea

STCW Standard Training of Certification and Watch keeping for Seafarer

SVDR Ship’s Voyage Data Recorder

UPS Uninterruptible Power Supply

VMS Vessel Monitoring System

VPN Virtual Private Network

WS Web Service


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WWW World Wide Web

10.2 Glossary used in the report

KVA - Kilovolt Ampere rating that is a measurement of the output of a transformer without

exceeding a certain temperature.

Load - The quantity of electric power supplied or necessitated at any particular spot in the

system. Also a requirement of the KVA or VA from the transformer; light bulbs are loads.

Magnetic Shielding - This conductive material attenuates stray magnetic fields by its

positioning around a transformer's coils.

Polarity - The direction of the current between two leads. If the directions are the same then

the leads have the same polarity. In electric transformers the polarity is classes as either

additive or subtractive.

Power Factor - Watts divided by volt amps, KW divided by KVA. Power factor: leading and

lagging of voltage versus current caused by inductive or capacitive loads, and harmonic

power

Apparent Power – Apparent Power is the product of the current and voltage of the circuit. it

is the power which is drawn from the power system.

Reactive Load – Reactive Load actually dissipate power which is called reactive power,

depending on the load and power factor of the network, the power factor controller will

switch the necessary blocks of capacitors in steps to make sure the power factor stays above a

selected value (usually demanded by the energy supplier), say 0.9

Filter - A complex system within the transformer that consists of capacitors, inductors, and a

resistor; it provides a relative small opposition to specific frequencies or direct current, as it

blocks or attenuates other frequencies.

Flexible Connector - A conductor that can handle thermal expansion and contraction as well

as reduce noise;

Impedance - That the forces that resist the flow of current in AC circuits like resistance.

Inrush Current - This is when the transformer has a short current surge through it, from

residual flux, occurring at the moment energy is applied to the transformer.


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Rated Power - The total of the Volts and Amps derived from all the secondary windings.

Resonance - A condition of an AC circuit in which capacitive and inductive reactance

interact, resulting in maximum or minimum circuit impedance.

Secondary Winding - On the load or output side, the connected transformer winding;

Sudden Pressure Relay - Pressure switch device which detaches the transformer from line.

Voltage - The measurement of the amount of force on a unit charge because of the

surrounding charges.

Voltage Taps - Supplemental connections to a winding which permit varying voltages from

the same winding; typically utilized on the primary winding to permit the transformer to be

used in different countries with varying line voltages

Distributed Generation Facility - A facility for the generation of electricity with a capacity

of no more than 15 megawatts that is located near the point where the electricity will be used

or is in a location that will support the functioning of the electric power distribution grid.

Distribution Feeder/Line - An electric line from an LDC substation or other supply point to

customers that is operated at 50 kV or less, or as determined by the LDC.

Arc Voltage - The voltage that appears across the contacts of circuit breaker during the

arcing period is known as arc voltage. Its value is low except for the current zero, at current

zero the arc voltage rises rapidly to peak value. It tends to maintain the current flow in the

form of arc.

Restriking Voltage - It’s the transient voltage that appears across the contacts at or near

current zero during arcing Period. This voltage is caused by rapid distribution of energy

between magnetic and electric fields associated with plants and transmission lines of the

system. Current interruption depends on this voltage. If the restriking voltage raises more

rapidly than dielectric strength of medium arc persists for another half cycle else arc will fail

to restrike.

Faradays Law of Electromagnetic Induction - The Revolutionary law so called faradays

lay of electromagnetic induction can be stated as below: Faraday's Law states that the induced


page 99

electromotive force in a closed loop of wire is directly proportional to the time rate of change

of magnetic flux through the loop i.e.,

dt

de

Or dt

dne

Where n is the number of loop. RMS value electromagnetic force depends on the loop. This

law is most significant because based on this law we are now producing electrical power to

run industrial wheel.

Ohm’s Law - The current (I) flowing through a conductor is direct proportional to the

potential difference (V) across its ends provided the physical conditions (Temperature, Strain,

etc) do not change i.e.,

VI

Or RI

VConstant

Where R is a constant of proportionality and is called resistances, which always oppose the

flow of current.

Voltage - Just like mechanical pressure (P) voltage is also called electrical pressure (V). This

pressure is used to move loosely attracted electron to the outermost shell of a conductive

material.

Current - In effect if electric potential (V) the flow of charge in a definite direction of a close

loop is called electric current (I).

Power - The power of an electric appliance is the rate at which electric energy is converted

into other forms of energy (e.g. heat, e.t.c).


page 100

10.3 Charts/Photos/Pictures/Videos

Fig showing M.V. Banglar Urmi anchored in the sea

(Source: Shipspotting, 2012)

Fig showing the ministry of shipping and its associated organizations

(Ref. Mercantile Marine Department, 2012)

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Internship Report on 'Power Generation, Utilization and Communication System of Marine Vessel

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