S u b m i t t e d b y B a t c h D , I I T M a d r a s

2012

COCHIN SHIPYARD

LIMITED

Industrial Training Report

Batch D: December 3rd – December 28th 2012

NA10B015 Katuri Anvesh

NA10B017 Mahesh Meena

NA10B043 Kalidasu Girish Kumar

NA10B010 Kaki Leela Krishna

NA10B047 Rinshad K

NA10B048 Sibananda Sahoo

NA10B040 Anurag Mishra

NA10B051 Ambetkar Vighnesh Vidyadhar

NA10B007 Chandan Biswas

NA10B053 Koppula Mouney

NA10B054 Ladongnuklu Jamir

NA10B057 Sayanth V

NA10B059 Kimudu Kurma Chandra

ACKNOWLEDGEMENT

First of all we would like thank Prof. P. Krishnankutty, Ocean

Engineering Department, IIT Madras for providing us this great

opportunity of industrial training under the guidance of Cochin

Shipyard Limited, Kochi as well as for his special lecture during

the training session

We would like to thank Mr P Sukumaran, GM Training and

Mr M. P. Ramadas, DM Training for allowing us to train under

their experienced staff.

We would like to thank all the managers, deputy managers,

chief managers and the supporting staff from different

departments for sharing their experience and guiding us with

knowledge of practical importance.

Cochin Shipyard Limited

Introduction

Cochin Shipyard Limited (CSL) is the largest ship building and maintenance facility in India. It is part of a line of maritime related facilities in the port-city of Kochi, in the state of Kerala, India.

Cochin Shipyard was incorporated in 1972 as a Government of India company, with the first phase of facilities coming online in 1982. The yard has facilities to build vessels up to 1.1 Million tons and repair vessels up to 1.25 Million tons, the largest such facilities in India.

The shipyard also trains graduate engineers in marine engineering. Around hundred students are trained each year.

Services offered by CSL

Ship Building Ship Repair Developing Marine Engineers

Facilities Overview

Steel Stockyard Area: 13000 m2 Covered Shops Area: 65000 m2 Steel Fabrication: 2500 tons/month Dry Docks:

o Building Dock:

Dimensions: 255m × 43m × 9m Lifting dock gates o Repair Dock:

Dimensions: 274m × 43m × 11.5m Flap dock gate Quays: 3 nos.

Q1 (290m), Q2 (208m), Q3 Two Gantry cranes one with a capacity of 300 tons, other with a capacity of

150 tons A transporter with a capacity of 150 tons, many cranes with smaller capacity

the assembly shop has a telescopic roof which moves over it to facilitate the operation of the gantry cranes.

Integrated Management System (IMS)

It is a combined Management System implemented in CSL. It consists of following certifications:

a) IMS 9001:2008

It is a Quality Management System (QMS). This certification stands for quality management in productivity and work output of CSL.

b) OHSAS 18001:2007 This is an environmental management system. This certification stands for fulfillment of environmental policy by CSL.

c) ISO 14001:2004 This certification stands for personnel safety in all working conditions of employees.

The basic procedure followed by the shipyard starting from obtaining the contract to delivering the vessel is shown. The design department deals with the key plans, yard plans, trial / testing and MLFs.

Division Department Section

Ship Building

Hull BD SBOC/S & C Outfit Planning SSD-Operations IQC

Ship Repair

Hull/ACR MR D & P EE & I SRP & M SRC

Services

Materials U & M Civil Design

Hull Structural Design Hull Outfit Design Accommodation Outfit Design Machinery Outfit Design Electrical Outfit Design

Projects

Supporting

HRD Finance ISD S & F Training/METI/FFTC

Design One of the services provided by CSL is DESIGN. Prior to the construction of a vessel, detailed drawings concerning the engineering as well as the architectural aspects of it are to be created. This task is accomplished by the Design Department.

Design of ship is completed in three stages.

1. Basic Design

It is the first step of designing a vessel. It depicts the basic hull form and is created from lines plan. It concentrates on the stability of the vessel, its hydrostatic and hydrodynamic particulars and mechanical properties like section modulus, strength etc.

Any basic design has to undergo various tests to practically calculate its efficiency and a design is deemed acceptable or not based on the results.

Wooden models are created as per the design and are tested for properties like resistance in a towing tank. This process requires many facilities and trained people which as of now are not available in CSL.

In CSL, basic design is available only for tugs of DWT 35-55 tons. So for other vessels like PSVs, FPVs basic design is purchased from companies like Rolls-Royce Marine and STX Europe. They have fixed designs (proven) for particular vessels like PSVs which are modified as per owner’s requirements. Basic Design package consists of key plans, one line diagram. This Design is a proven design i.e. economically feasible and meeting owner’s requirements. For a purchased design, parameters such as hull form, cargo capacity, speed etc. are fixed.

Stages of Design

Basic Design Preliminary

Design Detailed Design

Basic Design is approved by any of the classification societies as specified by owner.

2. Preliminary Design(Key Plan)

Key plans consist of drawings like SHELL EXPANSION TRANSVERSE SECTIONS AFT/FORE END DRAWINGS LONGITUDINAL DECKS SUPER STRUCTURE PIPING AND INSTRUMENT DRAWING WIRING DIAGRAM GENERAL ARRANGEMENT

They give an idea about the various systems, machines in the ship, various sections and their dimensions. Steel to be used for construction is to be of Ship Building Quality (SBQ).

3. Detailed Design (Yard Plan) The ship is divided into blocks/units to increase ease of design and production. They are constructed individually, simultaneously and are welded together during the Grand Assembly. Each unit has its own yard plan. Criteria employed for this division are - crane carrying capacity of the yard - strength of each unit

Yard plan consists of

DETAILED KEY PLAN NESTING PLAN FITTING PLAN MATERIAL LIST OF FITTINGS (MLF)

The detailed key plan consists of each measurement and the name of each part in a unit. Systematic naming of all the parts is a very important part in the design. The name indicates various aspects of the position of the part.

e.g.

03KNMDKW3P 03 - Unit number KN - Knuckling MDK - Main deck W - Plate 3 - Plate no. P - Port side

The Nesting plan is a drawing showing how to fabricate the parts required out of a steel plate. It is made in a manner to reduce wastage and increase production rate.

The fitting plan shows

The positions of parts to be fitted in various views. (the coordinates of positions are mentioned, i.e. the distance from nearest frame)

Orientation of the fittings. The type of welding to be used.

The MLF is very important part of the yard plan. It has details of all the parts which are to be used while building the unit. The officer in charge can use it as a checklist of sorts to confirm that all the parts have been accounted for before outfitting or fabricating. This helps in reducing time taken for production as it can be ensured that work doesn't stop due to shortage/absence of material required.

COMPUTERISATION

Before the development of computers, the designing was done manually on paper using drafters. All the drawings were done in full scale. It was a tedious and time consuming process.

But since the introduction of computers, the designing process has become much easier. Many softwares have been introduced to produce 2-D drawings.

In CSL, recently TRIBON has been introduced.

TRIBON is a family of programs that create and refer to a common set of databases containing the design details of the ship. Together, these databases are used to depict a 3D model of the ship, with embedded information for all of the parts of the design, from ship structural elements to pipe segments to equipment. Many common ship design elements, especially equipment, can be downloaded from databases. The software brings about an increased degree of inter department cooperation, as each department modifies the same model and we can observe any collisions and route pipes and cables accordingly.

SECTIONS IN DESIGN DEPARTMENT

The design of a vessel is divided into five sections, with a team of people focusing on one particular section. The advantages of doing so are in its convenience, greater detail in designing and increasing the overall efficiency.

Design Department of CSL consists of five sections:

• Hull Structural Design(HSD) • Hull Outfit Design(HOD) • Accommodation Outfit Design(AOD) • Electrical Outfit Design(EOD) • Machinery Outfit Design(MOD)

Hull Structural Design (HSD) This section deals with Basic hull form of the vessel Framing system- either transverse or longitudinal Scantlings of Stiffeners

They develop the basic design to suit the requirements of the contractor i.e. the ship dimensions, number of decks, number and types of cargo tanks etc. The main focus if this section is on the stability and strength of the vessel.

Hull Outfit Design (HOD) This section deals with the outfitting in all the areas except the engine room and the accommodation. The main aspects of hull outfit department are:

Piping, access items and machinery seats of following systems: Base Oil system Fuel Oil system Lube Oil system Fresh Water system

Ballast Water system Sea Water system

Compressed Air system Sewage system Exhaust system Tank washing system Fire fighting system Tank sounding system Water Mist system Hydrophore system Quick closing valve system Bulk handling system Drain system and other systems based on the cargo.

Bollard Capston Anchors Ventilators Cargo pumps

All these various systems have piping which comes under outfitting. The seats of machinery, ladders, anchor design, the mooring bollards, the chocks etc all come under outfitting and they are designed under this section.

CSL follows the IHOP system for outfitting. Integrated Hull Outfit and Painting is a system which reduces production time and increases ease of access while outfitting. Each of the units is outfitted with pipes and other parts before the grand assembly to the maximum extent possible. This is possible because of the accuracy of design plans generated by TRIBON. All the parts of each unit are joined together by various means after the grand assembly. But the major setback being faced currently while following this system, is the availability of all the outfit parts required.

Accommodation outfit Design (AOD)

This section in design is responsible for all the outfitting in the accommodation section of the ship like piping system, sanitary system, water supply, discharge, drain system, fire fighting system, rescue boats, HVAC, the navigation and communication systems etc.

Insulation

Insulation is another major aspect. The decks above the main deck are used for accommodation purposes and as per regulations; they are required to be insulated from sound, heat and fire.

Types of insulations:

Fire Thermal and sounding

AOD

Piping Structures:

Ladders,Equipment Seats,Masts

Accomodation: Insulation,Panelling,Deck

Covering,HVAC system

Fire Insulation

According to SOLAS rules by IMO “A” class Divisions and “B” class divisions are defined as follows:

‘‘A’’ class divisions are those divisions formed by bulkheads and decks which comply with the following criteria:

they are constructed of steel or other equivalent material they are suitably stiffened they are insulated with approved non-combustible materials such that the

average temperature of the unexposed side will not rise more than 140⁰C above the original temperature, nor will the temperature, at any one point, including any joint, rise more than 180⁰C above the original temperature, within the time listed below:

Class ‘‘A-60’’:60 min

Class ‘‘A-30’’:30 min

Class ‘‘A-15’’:15 min

Class ‘‘A-0’’ :0 min

they are so constructed as to be capable of preventing the passage of smoke and flame to the end of the one-hour standard fire test

The Administration required a test of a prototype bulkhead or deck in accordance with the Fire Test Procedures Code to ensure that it meets the above requirements for integrity and temperature rise.

‘‘B’’ class divisions are those divisions formed by bulkheads, decks, ceilings or linings which comply with the following criteria:

they are constructed of approved non-combustible materials and all materials used in the construction and erection of ‘‘B’’ class divisions are non-combustible, with the exception that combustible veneers may be permitted provided they meet other appropriate requirements of this chapter

they have an insulation value such that the average temperature of the unexposed side will not rise more than 140⁰C above the original temperature, nor will the temperature at any one point, including any joint, rise more than 225⁰C above the original temperature, within the time listed below:

Class ‘‘B-15’’:15 min

Class ‘‘B-0’’ :0 min

they are so constructed as to be capable of preventing the passage of flame to the end of the first half hour of the standard fire test

The Administration required a test of a prototype division in accordance with the Fire Test Procedures Code to ensure that it meets the above requirements for integrity and temperature rise.

Thermal and Sounding insulation

Main purpose is comfort of people onboard. For comfort regulation there is a class COMFV3. According to this regulation, sound level in accommodation area should be less than 60dB. In CSL, for PSVs Floating Floor insulation has been implemented.

Doors are classified as follows:

1. Internal: “A” class, “B” class 2. External: Watertight, Weather tight, Spray tight

Further doors can be Left Hinged or Right Hinged.

HVAC (Heating Ventilation Air Conditioning) System (Key plan)

Typical system details are listed as follows

System Fan Capacity Duct Ventilation Opening

Typical Accommodation plan consists of following:

Passage Space Storage space Living Space

Cabins are prefabricated with optimum space use (Modular systems). Components of cabin are as follows:

i. Wall Panel ii. Ceiling Panel

iii. Marine Door iv. Unit toilet v. Interior Furnishing

Fire and Safety Equipment plan is to comply with the requirements as per SOLAS.

Electrical Outfit Design (EOD)

The EOD team is responsible for the design of all the electrical equipment present in the entire ship as well as for all the cabling in the ship. They take care of the wiring, distribution boards, circuit boards etc.

It consists of following sections:

Power - Generation - Transmission - Distribution

Lighting Fire Alarm and Detection Navigation, Radio Communication Control and Monitoring

e.g.

C-BA 14

C- Navigation, Radio Communication

BA- Bridge Alarm

14- Component No.

For routing of cables “wiring diagram” is followed. It represents complete system. For termination of cables “connection diagram” is followed. For laying of cables “cable schedule” is followed.

EOD has to play a coordinated role with the other design departments. The EOD designs the location and position of the cable trays. The cable trays contain the all the cables attached to it by a tightening band. The cable trays are designed to minimize the usage of cables. There is a main cable tray which runs from the forward to the aft of the ship. This has some trays which branch out and reach all the necessary areas. The cabling schedule is done manually by the EOD team. The scheduling decides how much length of wire has to be drawn from cylinder and for which connection. This is done keeping in mind, the aim to have minimum wastage of cable.

Machinery Outfit Design (MOD)

This section is responsible for machinery and piping in the Engine room. Along with the preliminary design, the firms like STX also provide the engine and the type of propulsion used. These are provided in the schematics or the key plans. The MOD team models all the piping and equipment in the engine room.

There are two basic types of design for transmission of power.

Diesel Mechanical - power transmitted through shaft Diesel Electric - mechanical power converted to electric using

generators.

Propellers, bow thrusters also come under this section. Companies like BMW, MAC, Rolls Royce and Caterpillar provide the engines, generators etc.

Typical List of systems in PSV under MOD:

Bulk Handling System

Fuel Oil Cargo System Fresh Water Cargo System Brine System Base Oil System Methanol-Special Product System Liquid Mud System Cargo Tank Washing System Low pressure hyd. System Wheel House Window Flushing System HVAC GA including Gas Zones Hydrophore System Sanitary Supply System Fuel Oil System Remote Control Quick Closing Valves Lubricating Oil System Sea Water Cooling System Fresh Water Cooling Systems Compressed Air System Exhaust Pipe System Ballast Water System Bilge Fire System Drain Pipe System External Fire Fighting System Vent Pipe System Tank Sounding System

Ship Building-Hull Ship building-Hull can be divided into four sections

• Preparation

• Sub assembly

• Assembly

• Hull Erection and Grand Assembly

The layout of Hull Shop of Cochin Shipyard Limited is shown below

Preparation

The preparation section is situated next to the steel stock yard. Since the preparation section uses steel plates and frames as the raw materials, it works along with the material department of the yard. The location of this section is in accordance with availability of cranes and other such facilities for easy handling of plates.

The plates and frames procured by the yard is stored in the steel yard which is then taken into the preparation section for mangling, blasting, painting, marking, cutting and forming as per the requirements of the design section.

Plate preparation

The steel plates from the stockyard are taken into the preparation section using electromagnetic cranes. Maximum lifting capacity of cranes is 50 tons. A semi-automatic roller conveyer system is used for moving the plates through the machineries.

The following processes are involved in plate preparation.

Mangling: The steel plates are first fed into the mangling machine for straightening the plates. During the mangling process the internal stresses of the steel plates are relieved. For mangling process altogether five rollers are used as shown in the figure below.

Plates with thickness between 6-30 mm can be treated this way. For plates with thickness greater than 30mm mangling is not necessary and for plates with thickness less than 6mm additional stiffeners are welded along the length. The gap

between upper and lower rollers will be 1 or 2mm less than that the thickness of the plate. The speed of the machine is 6000 mm/min.

Blasting: After mangling; the steel plates are fed into blasting machine to remove the rust, dirt on the surface and also for roughening of the surface. While plates pass through the blasting machine small pellets of iron (approximate diameter 2mm) are shot from guns situated inside the upper and lower side of the blasting machine. Capacity of plate blasting machine:

Size: Width= 900 mm to 3500 mm

Length= 2500mm to 13000 mm

Thickness= 6mm to 50 mm

Blasting Speed= 3-4 m/min

There are different standards of blasting such as SA212 depending on the

requirement.

Painting: After blasting, the plate is fed into painting and drying machine, where zinc primer coat of approximate 100 micron thickness is sprayed on to the plates by the four spraying units inside the painting machine with a pressure of 2 kg/cm2 by a pneumatic pump and compressor. The heat generated here dries the paint there itself.

Drying: Most of the paint dries as soon as it is sprayed, and the plates are passed through a dryer which completes the drying and absorbs the paint fumes from the plates.

Cutting

The plates are then taken for the cutting and marking. Plasma cutting and gas cutting are the two types of cuttings used in the shop. Plasma cutting is four times faster than the gas cutting however the maximum thickness of plate that can be cut by the plasma machine is much less compared to gas cutting.

Gas cutting: In gas cutting, high pressure oxygen is pumped at high temperature which oxidizes the region to be cut. For maintaining the temperature acetylene and CO2 are used. Marking of the plate for cutting is done by burning zinc powder which leaves a mark on the plate without an impression. The program (generated by

TRIBON) for cutting the plate, is then fed into the machine and the tip is accordingly positioned over the plate. Once the cutting is done the parts are marked manually and carried by cranes to the sub assembly section.

CNC Gas cutting Machine:

Cutting Speed: 1000 mm/min (max)

Marking Speed: 12000 mm/min (max)

Width of plate: 8000 mm (max)

Plasma cutting: In plasma cutting, tungsten electrode is used as the filament. When high electric potential is provided between electrode tip and nozzle tip, it ionizes oxygen atoms around it which collides with each other to release heat. The high temperature melts the steel and removes it along a thin region where the marking is made and thus cutting it. Nitrogen gas is provided as a shield in plasma cutting. Marking is done using zinc powder as in gas cutting. Program is then fed into the machine and initial coordinates set to perform the cutting.

CNC plasma cutting Machine:

Cutting Speed: 6000 mm/min (max)

Marking speed: 24000 mm/min (max)

Width of plate: 3500 mm (max)

Shear cutting: Shear cutting is the simplest form of cutting. Its action is similar to a scissors. The metal piece is properly positioned along the high carbon steel and manually using legs the other half of the blade is lowered to cut the plate. The method is faster and pollution free but needs more effort with limited cutting possibilities.

Once the cutting is over the plates is taken for forming.

Forming

In forming, roller bending and hydraulic bending are used.

In roller bending, plate is rolled over two rollers with a third one on top arranged in accordance with the radius of curvature required. Plates are passed through the

rollers in such a way that the line drawn on the plate is parallel to it as shown in the figure below.

Once the bending is done, the plate is checked using the wooden templates provided by the mould loft section based on the design.

SECTION PREPARATION

In section preparation, various parts such as stiffeners, angles, bulb bars, frames etc. are prepared according to the nesting plan provided from the design section. First these sections are straightened using the frame bending machine. Cutting of these frames is done to desired lengths using gas cutting along with which bevelling is done. Then these sections are bent as per the requirement using Inverse line bending technique.

Inverse Line Technique: In inverse line bending technique, first the section is straightened with the help of beam bender. Then a line, known as the inverse line, is drawn manually on the section according to the data given by the design section. Then this frame is fed into the frame bending machine. Once the bending is done, the inverse line is checked. When the bend is right the line becomes straight.

MOULD LOFT

It is here, the templates for the forming section are made. From design section, film containing the shape of section of the plate is given in a 1: 10 scaled ratio. This is then projected to actual size and the templates are made accordingly using wood. In sheet bending and frame bending, these templates are used for checking the accuracy of the bend. Minimum number of templates required to define the shape of a plate arr provided by mould loft .For complicated 3d shapes such as bulbous bow, complete template is made.

SUB ASSEMBLY

In sub assembly, welding of the frames are done according to the requirements of the design section. For plates only tack welding is performed. Most of the welding and grindings are carried out in the sub assembly shop itself. Grinding is where excess weld is removed. The welding methods used are mainly manual arc welding, CO2 arc welding and submerged arc welding. For welding, if the thickness is more than 8mm then edge preparation is done. Bevel cutting is done with bevel angle=30⁰

Manual Arc Welding: Manual welding is the most common welding method where different graded welding rods are used and it uses a welding power supply to create an electric arc between an electrode and the base material to melt the metals at the welding point.

Gas welding: In gas welding LPG, oxygen and compressed air is used .LPG gas welding can be used only for ferrous materials. For the shielding either CO2 or argon gas or mixture of both is used. A welding torch is used to weld metals. Welded metal results when two pieces are heated to a temperature that produces a shared pool of molten metal. The molten pool is generally supplied with additional metal called filler.

Submerged Arc Welding: Submerged arc welding is an automatic process in which the welding metal and arc are completely immersed in flux. When molten, the flux becomes conductive; it provides a current path between the electrode and the work. This thick layer of flux completely covers the molten metal thus preventing spatter and sparks as well as suppressing the intense ultraviolet radiation and fumes.

Submerged arc welding is the strongest followed by CO2 gas welding and manual.

General Welding Defects

• Lack of fusion

o Possible Causes

Incorrect arc power

Welding speed too high

Welding vertical down

Asymmetrical aiming of the arc

o Corrective Action

Increase arc power

Adjust welding speed

Weld vertical up

Change the arc angle

• Porosity

o Possible Causes

Shielding gas moisture

Contaminated material

Weld through primer thickness

o Corrective Action

Check gas type and coverage

Ensure weld piece and filler is dry

Check parent material and joint face

Check manufacturer’s specifications

• Slag inclusions

o Possible Causes

Arc power too low

Arc length too long

Poor joint preparation

Slag flooding ahead of weld pool

o Corrective Action

Increase arc power

Shorten arc length

Prepare and clean joint

Aim arc towards molten pool

• Undercut

o Possible Causes

Arc length too long

Voltage too high

Arc power too high

Excessive weaving of the electrode

o Corrective Action

Reduce arc length/voltage

Adjust arc power

Change/tighten technique

• Excessive Asymmetry of fillet weld

o Possible Causes

Incorrect electrode angle

Weld pool too large

Magnetic arc blow

Arc length too long

o Corrective Action

Use correct electrode angles

Reduce deposition rate

Reposition the earth clamp/cable

Shorten arc length

• Excess Weld Metal

o Possible Causes

Too much filler metal in relation to the cooling speed

Electrode diameter too large

o Corrective Action

Increase travel speed or reduce the amount of filler metal

Select proper electrode diameter

• Excessive penetration

o Possible Causes

Heat input to joint is high

Root gap too large

Root face too small

o Corrective Action

Reduce welding power

Adjust root gap

Enlarge root face

• Lack of penetration

o Possible Causes

Point joint design

Welding power too low

Excessively long arc length

Welding travel speed too fast

o Corrective Action

Increase root opening or decrease root face

Increase power

Reduce arc length

Decrease welding speed

• Linear misalignment

o Possible Causes

Poor component fit up before welding

Tacks break during welding

o Corrective Action

Ensure correct joint alignment

Use correct welding sequence

Improve tack welding quality and positioning

• Crater crack and Crater pipe

o Possible Causes

Weld pool shrinkage during solidification

Welding power level reduced too quickly

o Corrective Action

Backstep slightly at end of weld

Reduce welding power progressively

• Spatter

o Possible Causes

Incorrect welding parameter

Incorrect welding polarity

Poor quality filler materials shielding gas coverage and type

o Corrective Action

Adjust welding parameters

Change polarity

Change filler materials and storage conditions

Check gas coverage and type

• Cracks e.g. hot cracks

o Possible Causes

Width to depth ratio of weld too low

High stress due to thermal expansion

Incorrect filler metal, base metal combination

Root gap too large

o Corrective Action

Ensure correct ratio

Control heating and cooling cycle

Match filler materials correctly

Adjust root penetration

Welding tests:

Non destructive testing (NDT) of welds

These are test methods to examine an object, material or system without impairing its future usefulness. Non-destructive testing is often required to verify the quality of a product or a system. Commonly used techniques are

• AET - Acoustic Emission Testing

• ART - Acoustic Resonance Testing

• ET - Electromagnetic Testing

• IRT - Infrared Testing

• LT - Leak Testing

• MT - Magnetic Particle Testing

• PT - Dye Penetrant Testing

• RT - Radiographic Testing

• UT - Ultrasonic Testing

• VT - Visual Testing (VI - Visual Inspection)

AET - Acoustic Emission Testing

Acoustic Emission Testing takes advantage of the sharp sound that PCCP emits when it breaks or slips to identify areas of active distress within a construction. AET can be used to verify the structural integrity of pressure vessels, spheres, high temperature reactors and piping, coke drums, above ground storage tanks,

cryogenic storage tanks and more. The inspection is executed externally and shut-down of the process may often not be necessary.

ART - Acoustic Resonance Testing

After an impact a specimen will vibrate in certain characteristic modes and frequencies that can be measured by a microphone or laser vibrometer. Acoustic sonic and ultrasonic resonance analysis is a non-destructive testing technique that allows testing of a wide range of test objects. Typical detecting faults are cracks, cavities, detached layers, material inconsistencies, hardness deviation in materials.

ET - Electromagnetic Testing

Electromagnetic testing is the process of inducing electric currents and/or magnetic fields inside a test object and observing the response. A defect in the test object may be detected where electromagnetic interference creates a measurable response.

IRT - Infrared Testing

Infrared testing is a technique that uses thermography, an infrared imaging and measurement camera, to see and measure infrared energy emitted from an object. It Can be used to heat development, lack of insulation, thin walls in constructions and more.

LT - Leak Testing

Techniques used to detect and locate leaks in pressure containment parts, pressure vessels, and structures. Leaks can be detected by using liquid and gas penetrant techniques, electronic listening devices, pressure gauge measurements or soap-bubble tests.

MT - Magnetic Particle Testing

Magnetic particle testing is accomplished by inducing a magnetic field in a ferromagnetic material and then dusting the surface with iron particles. The surface will produce magnetic poles and distort the magnetic field in such a way that the iron particles are attracted and concentrated making defects on the surface of the material visible.

PT - Dye Penetrant Testing

The dye penetrant testing can be used to locate discontinuities on material surfaces. A highly penetrating dye on the surface will enter discontinuities after a sufficient penetration time, and after removing the excess dye with a developing agent, the defects on the surface will be visible.

RT - Radiographic Testing

Radiographic testing can be used to detect internal defects in castings, welds or forgings by exposure the construction to x-ray or gamma ray radiation. Defects are detected by differences in radiation absorption in the material as seen on a shadow graph displayed on photographic film or a fluorescent screen.

UT - Ultrasonic Testing

Ultrasonic testing uses high frequency sound energy to conduct examinations and make measurements. Ultrasonic inspection can be used for flaw detection/evaluation, dimensional measurements, material characterization, and more.

VT - Visual Testing (VI - Visual Inspection)

Visual testing or inspection offers a wide range of options to secure proper system or product quality.

Destructive Testing of Welds

Destructive weld testing, as the name suggests, involves the physical destruction of the completed weld in order to evaluate its characteristics. This method of testing is used frequently for a number of applications. Some of these applications include welding procedure qualification and welder performance qualification testing, sampling inspection of production welds, research inspection, and failure analysis work. A number of destructive weld testing methods are used to determine weld integrity or performance. Typically they involve sectioning and/or breaking the welded component and evaluating various mechanical and/or physical characteristics. We shall briefly examine some of the more common methods of this type of welding inspection. We shall consider the macro etch test, the fillet weld break test, the transverse tension test, and the guided bend test. We shall consider how they are used, and what types of weld characteristics they are designed to determine. We shall examine their advantages over other inspection methods and their limitations.

Macro Etch Testing – This method of testing typically involves the removal of small samples of the welded joint. These samples are polished across their cross-section and then etched using some type of mild acid mixture, dependent on the base material used. The acid etch provides a clear visual appearance of the internal structure of the weld. Particular interest is often shown at the fusion line, this being the transition between the weld and the base material. Such items as depth of penetration, lack of fusion, inadequate root penetration, internal porosity, cracking and inclusions can be detected during inspection of the etched sample. This type of inspection is obviously a snapshot of the overall weld length quality when used for sampling inspection of production welds. This type of testing is often used extremely successfully to pinpoint welding problems such as crack initiation, when used for failure analyses.

Fillet Weld Break Test – This type of testing involves breaking a sample fillet weld that is welded on one side only. The sample has load applied to its unwelded side, transverse to the weld and directed to its unwelded side (typically in a press). The load is increased until the weld has failed. The failed sample is then inspected to establish the presence and extent of any welding discontinuities. This test will provide a good indication as to the extent of discontinuities within the entire length of weld tested (normally 6 to 12 inches) rather that a cross-sectional snapspot like the macro etch test. This type of weld inspection can detect such items as lack of fusion, internal porosity and slag inclusions. This testing method is often used in conjunction with the macro etch test. These two testing methods complement each other by providing information on similar characteristics in different detail and in different ways.

Transverse Tension Test – Since a large proportion of design is based on tensile properties of the welded joint, it is important that the tensile properties of the base metal, the weld metal, the bond between the base and the weld, and the heat-affected zone conform to the design requirements. Tensile strength of the welded joint is obtained by pulling specimens to failure. Tensile strength is determined by dividing the maximum load required during testing by the cross-sectional area. The result will be in units of tension per cross-sectional area. This test is nearly always required as part of the mechanical testing when qualifying welding procedure specifications for groove welds.

Guided Bend Test – This is a test method in which a specimen is bent to a specified bend radius. Various types of bend tests are used to evaluate the ductility and

soundness of welded joints. Guided bend tests are usually taken transverse to the weld axis and may be bent in plunger type test machines or in wrap-around bend test jigs. Face bend tests are made with the weld face in tension, and root bend tests are made with the weld root in tension. When bend testing thick plates, side bend test specimens are usually cut from the welded joint and bent with the weld cross section in tension. The guided bend test is most commonly used in welding procedure and welder performance qualification tests. This type of testing is particularly good at finding liner fusion defects, which will often open up in the plate surface during the testing procedure

ASSEMBLY

In assembly shop; the materials are received from the sub assembly as well as the preparation section. The units are combined through welding in the assembly shop to form the blocks.

GRAND ASSEMBLY

In grand assembly; the blocks fabricated in the assembly shop are combined by welding. They are first positioned using cranes. Weight of each block is less than 50 tons which is maximum lifting capacity of cranes.

PAINTING

The huge blocks are then painted according to the paint scheme, which includes blasting, primer, coal tar, tie coat, anti-fouling etc.

HULL ERECTION

After painting the Grand assembly units are placed one by one in the dry dock according to the dry dock plan provided by the design section. Grand assembly units are thus welded to finish the hull of the ship.

Certain units are manufactured by subcontractors assigned by CSL because of lack of manpower.

In dock, CL, half breadth, ford end are aligned with the help of crane, hydraulic push pull jacks. Maximum allowance is 2 mm.

Staging is placed in dock. It consists of scaffoldings of width=1.5m

After alignment, welding of blocks is performed. It includes welding of deck, bottom, side shell, stiffeners, brackets etc.

Quality Control ensures rectification of defects before welding

After welding, various tests are performed to ensure quality of welding in presence of owner and classification society surveyor.

After all tests, painting of blocks is performed.

At last, staging is removed and vessel is ready for launching and further outfitting.

Ship Outfitting Ship outfitting involves fitting of pipes, machinery,carpentary and electrical equipments etc. on to the ship hull as per the design. The entire structure is divided into smaller units, blocks and bigger grand assemblies for organizing the outfitting work.

Outfitting is carried out in the following steps -

1. Block Stage Outfitting (IHOP – Integrated Hull Outfit and Painting). A big part of the outfitting is carried out in the block stage itself. It is tried to outfit all the necessary components and prepare spaces for machinery outfitting.Outfit items to be fitted at block stage are as follows:

• Ladder • Man Hole Cover • Bilge Well Cover • Pocket for Lashing Eye • Ring Plate for Lashing Eye • Bottom Plug • Anode • Hand Grip • Step

2. Unit Assembly (Modular Outfitting) 3. On Board Outfitting

Final touch to the outfitting work takes place. Disjoint units are joined and machines are outfitted accordingly as per the design. Electrical outfit and accommodation outfit are major works in this stage.

Each unit to be outfitted has an associated MLF (Material List of Fittings). An MLF is a list indicating the item number, description like diameter, schedule, material, pallet, availability and quantity etc. CAD drawings are passed n to the Pipe Shop and the Sheet Metal Shop and they prepare the pipes, ducts, supports and other outfits accordingly.

Ship outfitting process can be sub classified as –

1) ERO – Engine Room Outfitting 2) DHO – Deck and Hull Outfitting 3) Machinery Outfitting 4) Accommodation Outfitting

PIPE SHOP

The pipe shop receives the CAD drawings for manufacturing the different kinds of pipes required for outfitting process. The pipe shop has the capability to bend, cut, weld and paint pipes to get to the desired structure. Galvanisation of pipes is outsourced. There are semi-automatic and fully automatic CNC bending and cutting machines. Welding facilities include Tungsten Inert Gas welding, Metal Inert Gas welding, Metal Active Gas welding, Manual Metal Arc welding, CO2 welding and Submerged Welding. Submerged welding is not used these days.

Main processes in the pipe shop –

1) Cutting 2) Bending 3) Fabrication and, 4) Pickling

Blasting/Derusting and painting.

Two main characteristics to define a pipe :-

a) NB (Nominal Bore) – Denotes outer diameter of pipe used frequently in shipyard as unit (50 NB = 60.3 mm).

b) SCH (Schedule) – For thickness of the pipe.

PIPE CUTTING

PLASMA PIPE CUTTING MACHINE Non-ferrous,Cupro-nickel & stainless steel pipes can be cut by plasma cutting

machine. Oxygen & Acetylene gases are used in cutting. In this process, an inert gas is blown at high speed out of a nozzle; at the same

time an electrical arc is formed through that gas from the nozzle to the surface being cut, turning some of that gas to plasma.

The plasma is sufficiently hot to melt the metal being cut and moves sufficiently fast to blow molten metal away from the cut.

Nozzle is of Tungsten which can allow high current (45 A-135 A). Plasma arcs are extremely hot and are in the range of 16,500 °C - 25,000 °C. Max.thickness of pipe that can be cut is 30-40 mm & speed of cutting is

4000m/min. Air,oxygen,Argon,Argon/oxygen mixture or Ar/H2/N2 mixture can be used as

gases for cutting. Water is used as coolant inside the cutting machine. For mild steel pipes we can use gas systems for cutting.

Abrasive cutting machine (3000 rpm)

PIPE BENDING

The pipe bending machine consists of the following parts:- MANDRIL – it’s used to avoid ovality and wrinkling in the inner circle when its

bending is being done. DYE-Various types of dyes are available like 2D,3D(2D-2*diameter of pipe). We

can get different diameter of bending by using different diameter dies. Clamp Pressure Dye

Normal pipe bending machine can be used for 10mm-50 mm thickness pipes. Large pipe bending machine can be used for 50 mm -150 mm thickness pipes. Higher the diameter of the bend, lesser the resistance to the flow and thus lesser

the damage to the flow. Bending can be done upto 2000. Pipes up to 150 NB can be bent at CSL. The bending machines are hydraulic powered. Slant Rule is used to measure the slant angle/check the correctness of bending.

FABRICATION

Materials used in the pipe – 1) Stainless steel (for exhaust pipes) 2) Carbon steel 3) Cupronickel – Navy Fire Line

Copper – sea water pipes, accommodation, fresh water.

Usually 900 elbow bend or 450 elbow bend is commonly available. For other type of elbows, we cut using elbow cutting machine.

Ost-Large thickness pipe, Pst-Low thickness pipe Steps for obtaining a 300 elbow from a 900 long radius elbow is as follows:

• Mark the central lines on both inner & outer side. • Measure the outer length of tube (L1). • Now find (L1/90)*30. Mark that length on other side. • Measure the inner length of tube (L2). • Find (L2/90)*30.Mark that length on inner side. • Put Right Square & mark & cut it using plasma cutting.

Tig welding & X-Ray welding is used to join two cut sections of pipe. While welding a small gap should be given by providing a thin rod there so that

uniform gap will be there throughout the section & welding can be done properly.

To prevent corrosion, following processes are done -: 1) Coating-galvanization 2) Painting-oil line (only outside)

PICKLING

Pickling is a metal surface treatment used to remove impurities, such as stains, inorganic contaminants, rust or scale from ferrous metals, copper, and aluminum alloys.

The pickling process is known as the 7 tank process. The tanks are 1) Derusting- The acids used are sulphuric and hydrochloric acid 2) Water rinsing 3) Derusting (blast chemical) 4) Water rinsing 5) Phosphating- purpose- to smooth the surface. It leaves a black colour coating

on the pipes. 6) Fresh Water rinsing. 7) Deactivating to make the pipes inert.

After dipping in the tanks, the pipes are brush painted.

PALLETISATION

Palletised pipes are finished goods.These pipes will be painted,galvanised,pressure fested,X-Ray fested & after palletisation is done pipes are kept in pallets.

According to MLF & Pallet Specification ,pallets are given. By storing the pipes more speed is obtained in production as pipes are organised. X-Ray is done in laboratory.Galvanisation is ootsourced & is done in Chennai or

Coimbatore.Painting is done in paint shop.

SHEET METAL SHOP

The sheet metal shop is mainly used for fabrication of pipe supports, ladders (vertical and inclined), hatches, bulwark doors, electrical equipment seats, handgrips,handrails, machinery seats, floorings,different tyes of angles,etc.

According to drawings & Bill of Material (BOM),fabrication is done. In every fabrication cutting & joining work is done. Types of cutting-

a. Abrasive cutting (heat) and carborundum blades. b. Oxyacetylene cutting (steel) c. Shearing Cutting-Shearing machine can cut 2.5m wide & 6mm thick MS sheets.It

can cut sheets in 0.65mm-6 mm thick range.Hydraulic shearing machine can cut 3.5m wide & 8mm thick plates.

d. CNC (Computer Numerical Controlling) machine cutting – Brass , Al, SS, MS , ferrous & non-ferrous plates are cut.

e. IK-54 Cutting Machine - Automatic Gas Cutting Machine.Template is fixed. Electromagnet will trace the boundary of template & cut the sheet in the shape of the template.Capacity:3-100 mm.Cutting Speed : 100-1000 mm/min

Types of welding :– a. MMAW – Manual Metal Arc Welding b. MIG – Metal Inert Gas Welding – Argon c. TIG – Tungsten Inert Gas Welding

Sheet-metal shop also manufactures ducts because pipes are not used for ducts. Pipes are not used as ducts because they are heavier, difficult to manufacture and meant for high pressure applications. Whereas ducts are meant for air circulation at normal atmospheric pressure and they allow more volume of air to be passed through them as compared to a circular cross section pipe.

Sheet metal shop also has the following machines:- a. Beam Bender/Press Break - For making clamps, channels, angles. Capacity-

210 T b. Plate Rolling machine –Fabrication of pipes of 300 mm dia to 2 m dia. c. Hydraulic Press – For making clamps , handles, straightening. Capacity: 50 T d. Pedestal Grinder –to remove excessmaterial & smoothening. e. Hand Grinder – for smoothening. f. Upright drilling machine g. Radial drilling machine –Drilling, boring, tapping.

Other stuff manufactured there – hand grips, ladder + steps, grating for sea chest

and bow thrusters . Smoothening of the sharp edges should be done so as to avoid the loss of paint

from that site and thus prevent corrosion – New Safety Requirement.

Platform Supply Vessels

For mooring purposes the mooring rope is pulled using winch and capstan. Incinerator – Burns the solid waste (waste from filters – fuel oil filter and lube oil

filter) , used the fuel oil to burn it. Level indicator of fuel oil in the incinerator is called sight glass.

HMI – Human Machinery Interface – Monitoring the machinery on board. Windlass – Handling the anchor chain handling (like a tugger winch but designed

especially for an anchor) Sea water and fresh water cooling system, the engine is cooled by fresh water

and the sea water cools the fresh water. Boiler – hot water for tank washing Sewage treatment plant- For treating black water. Main switch board room Compressor – needs 30 bar pr. To start the engine For this vessel each engine 916volts Fuel oil separator and lube oil separator separate oil from bilge storage space ICCP – Impressed current cathodic protection to prevent rusting/corrosion Booster Compressor – Methanol will be feed with inert gas (Dinitrogen) (200 bar

pressure) BHS – Bulk Handling System For methanol pumps we can’t use electrical power (inflammability) and use

hydraulic power. VFD – Variable Frequency Drive, glycol is used as coolant

BY89/BY90

Name of BY89 ship : SEA TITUS

Name of BY90 ship : SEA TANTALUS

Owner : SEATANKERS MANAGEMENT, LIMASSOL, CYPRUS

USE : Cargo supply (Fresh Water , methanol ,cement ,mud ,base oil, fuel oil to rig )

The detailed design is given by design department. Various outfitting is done according to the different MLFs. The significant parts in the PSV in the outfitting point of view are-

• PSV has three major bulkheads dividing the ship into bow part, engine room and deck hull part.

• Tugger winch - It is used to move heavy objects along the deck. • Workshop - This consists of lathe machine, drilling machine provided with vices

for emergency purposes. • Control room:- In this room, major controls like ballast level control,

pneumatically and hydraulically operated valves and other parameters like pitch can be monitored and controlled.

• Engine room:- This is present in the forward region of the PSV. There are four generators mainly for propulsion, machinery, HVAC, thrusters and a harbour generator for usage in ports and in case of emergency. There are two starting air compressors to compress air and feed it to the engines. There are instrument air compressors for controlling pneumatically operated valves. Hydrofore system to provide fresh water to hull region. In this 75% of the tank will be water and rest will be compressed air to pump water to top. There are UV sterilizers and Calorifiers to heat. Calorifier or hot water tank is used to supply hot water to kitchen (galley), accommodation area and for bathing. All the leakage water/oil will be collected at the bilge pit which will be then separated by Oily- Bilge Water Separator and pumped out. For cooling purpose there are heat exchangers and box coolers. In heat exchangers sea water and hot fresh water are passed parallelly causing heat transfer. Box coolers are immersed in the sea water and hot water is passed though them. Every engine has two box coolers. This avoids the need for pumping sea water into the ship but it’s maintenance is possible only while dry docking.

• It has an emergency generator , 2 tunnel thrusters of 700- 800 KW capacity, one electric propulsion motor of 1600 KW. Each main generator has a capacity of 1200 KW & has 1800 rpm.Generator produces a voltage of 690 V .It has phase to phase connection & there is no neutral connection.

• It has DP2 system for dynamic positioning. Bow thrusters are provided for this. • There are three fuel oil tanks comprising of two service tanks and a settlement

tank. There is a fuel oil separator to test the purity of oil and similarly for lubricating oil. A flow meter is used to measure the amount of oil used by engine.

• A sewage treatment plant:- the sludge is taken to incinerator which burns (oxidation) the sludge and fumes are let out by exhaust pipes.

• There are turbo chargers attached to the engine which use energy from exhaust gases.

• There are eight mud tanks and six cement tanks. To pump out the cement, hot compressed air is used.

• Caging:- Exhaust pipes from incinerators and emergency generators pass through caging from deck to top.

• Thrusters are used for dynamic positioning while unloading the cargo near the platforms. These are used to arrest the motion in the transverse direction. In emergency conditions swing up thrusters can be used to propel the ship.

• Two azimuthal propellers are present in the aft region. • It has cargo rail from which cargo (fuel, chemicals,brine,mud, fresh

water,cement) is transferred to the rigs. • There is Hydraulic Power Pack to control flow oil,lubricant flow in hydaulic

elements. • Insulation is done by using mineral wool pads & over that Al foil is used as

covering. Types of insulation used are

- Comfort Insulation

- Thermal Insulation- For A/C.Density :32 kg/m3

- Accoustic Insulation- For vibrational sound.Density :62 kg/m3

1) Fire Insulation- Density :100-200 kg/m3 A-60 i.e. it can resist the fire upto 60 minutes

2) A-30 i.e. it can resist the fire upto 30 minutes • Jacket water Pre-heaters are used to pre heat the engine in cold countries. • In cochin shipyard we follow IHOP (integrated hull outfit and painting). This

method simplifies the work by methodically scheduling each process at each stage.

• If the engine temperature raises above a certain level a solenoid valve opens and releases a mixture of water and mist through a nozzle for fighting.

BY86

Dimensions

• Length = 78.7m • Breadth = 16m • Depth = 6m • D.W.T = 3060 Tonnes • Name : S.C.I YAMUNA

• Owner : S.C.I

Specifications

• Maximum Speed = 14.8 Nau miles • Design (hull) is by the company Rolls Royce. • Engine – Caterpillar • Frame spacing = 600mm • Type of Propeller used is Azimuthal Propeller ( i.e. 360 ͦ rotation) • 2 pairs of Bow thrusters in the forward • Main Deck contains the opening to the Mud tanks. In total there are eight

cylindrical shaped mud tanks and there are six cargo tanks, one in between each mud tank.

• The fuel tank comprises of suction and distribution pipes for the purpose of removing and filling the tank resp.

• Engine room is present at the tank top. • Cement tank room or cargo room has fresh water pump • 5 cement tanks are present with compressed air in it. • Engine room

- It consists of control panels i.e. sea water pumps and fresh water cooling systems

- Pump room contains Base oil for lubrication of engine - Mud tank has screw pump with high pressure for the removal of the

solid material. • The sub frames comprises of various rooms. • Paint store • Chemical store • CO2 room • Workshop room : A pipe line from Acetylene room and Oxygen room will be send

to this section for various operations and also for emergency situations like for cutting the anchor rope in case it is stuck.

• Officer’s Mess • Galley room (kitchen) • Tri- provisional room or cold room • Incinirator room • ERRV module – additional room for recovery purpose • Types of Insulation used are

- Comfort or Thermal Insulation - Sound Insulation - Fire Insulation

3) A-60 i.e. it can resist the fire upto 60 minutes 4) A-30 i.e. it can resist the fire upto 30 minutes

IAC (Indigenous Aircraft Carrier)

Dimensions

• Length overall (LOA) = 262.5m • Length between perpendiculars (LBP) = 233.2m • Breadth at waterline = 32.4m • Breadth (max.) at flight deck = 59.2m • Depth (upto deck no. 1) = 25.6m • Draft (max.) = 8.4m • Deep Displacement = 37500 tonnes

Specifications

• Maximum Speed = 28 knots • Cruising speed = 18 knots • Frame Spacing = 1.1m • It can carry 30 aircrafts at a time. • It can withstand nuclear and biological attacks. • Has 5 superstructure decks and 9 decks in the hull (including the flight deck) • Divided into 7 zones. They have biological and nuclear proof partitions. Thus

when one zone is affected, other zones can be functional. • There are two engine rooms- in the forward and aft. The carrier is powered by 4

gas turbines (G-2400). It also has 8 diesel alternators of 3MW capacity each. It has a controllable pitch propeller for propulsion and a rudder for steering.

• The complement of the ship is 1460 people including 300 officers. • The aircrafts are stored in the hangar which is on the 4th deck. It also has 2

turntables and 2 lifts to transport aircrafts from hangar deck to flight deck. • It also has 4 passenger and 5 ammunition lifts. • The first 4 decks from the flight deck are used for accommodation and the decks

below are used for machinery. The 5th deck houses the communication equipment of the vessel.

• As the length of the ship is insufficient to stop an aircraft, therefore an arresting mechanism is used while landing of aircraft. It is a cross-rope with a spring mechanism. For the take-off, the aircraft is kept stationary until enough thrust is produced by the jet engines for take-off in a shorter runway. It has a ski-jump with an inclination of 4 degrees and a length of 10m

• The trials are scheduled for 2015 and endurance test is done for 320 days. • Indian navy has its own standards regarding the construction of the vessel. IMO

regulations are only followed for navigation. • The torpedoes are guided by magnetic, infrared and acoustic signatures. The IAC

has an in-built mechanism to produce a false magnetic field. Magnetic coils cover the entire ship in both transverse and longitudinal directions. Normal exhaust temperature is around 200-300 degree C. Fresh air is added to the exhaust to reduce the temperature of the exhaust so that infrared signature can be fouled.

• FFE- It has 18 fire pumps.

• It has a 640 tonne air conditioning system which uses chilled water to transfer the cooling.

• To prevent corrosion, sacrificial anode. • It has 26 rings namely A-Z. • There are tanks which are three decks deep. • There are two engine rooms one in forward and second in aft. Each engine room

has three diesel alternators. • T2a0SCP0000-500-1- an example of nomenclature of pipe outfitting. Here T2A

represents deck and hull; similarly we have for other departments also. SS represents salvage system. C represents ring name P represents port side. The other digit represents the other specifications.

• It is made up of light weight material but its strength is not compromised. • Aviation fuel tank is surrounded by coffin room.

Ship Repair Dry dock repairs can be split into

• Hull Repair

• Accommodation repair

• Machinery repair

• Electrical repair

• Underwater painting

• Surveys by classification society

DRY DOCKING

A dry dock is a narrow basin or vessel that can be flooded to allow a load to be floated in, and then drained to allow that load to come to rest on a dry platform.

Dry docks are used for the construction, maintenance, and repair of ships, boats, and other watercraft

DOCKING REQUIREMENTS :

Docking Plan.

Block Setting & Marking.

Flooding.

Tugs & Boats.

Mooring crew.

Cranes on both sides.

Capstons

Winches

Hauling carriage

Reference line, Mouse & ropes

Docking plan- it’s a plan issued by the designer, in which the positioning of the blocks is explained. There is more than one docking plan for each ship. Once it is docked according to one docking plan, next time will be docked with another plan. So the places where the blocks were placed at last time will be repaired.

Block settings and markings- arranging of the blocks on the dock floor based on docking plan. They should not be placed under hull plates where there are no stiffeners. Likewise only docking plan will indicates the block arrangement. If a block placed on a part where there is no stiffener that plate will be buckled and damaged. So it is very important to arrange the blocks as per docking plan. Usually blocks are made by concrete, iron and wood which can adjust their height according to the shape of the ship. Reference lines will be marked on the dock to indicate the exact position of the fore and aft of the ship while docking. Bow line is one of the lines which helps for the positioning of the ship, which is the line at which bow of the ship should be aligned such that the ship will seat exactly on the blocks. Centering point is another marking where the bow of the ship is to be aligned.

REPAIR DOCK FACILITIES

Repair dock size : 274 x 43 x 11.5 mtrs

Quay : Q1(290 m),Q2 (208 m).

Ropes : Head rope, Spring rope, Breast rope, Stern rope, Steel

rope, Heaving line.

Pumps(MDP) : kirloskar Vertical turbine pump BHM-85 (three nos).

Discharge-15200 m3/hr, power-650KW , Rpm-480

Head-10.6 ,Delivery pipe diameter –Φ 1200mm.

: Mud pump(2 nos) Toyo denki.

DP-50:

Discharge -720m3/hr , power -37KW, Rpm -600,

Head -28m, Discharge pipe diameter -Φ 150mm.

DP-75:

Discharge –600m3/hr , power –55KW,

Discharge pipe diameter -Φ200mm.

• Dock gate : Flap gate • Keel blocks : 1.5 x 900 • Bilge blocks :1.20 x 450 • Fabricated Bilge blocks :Dimensions vary depends upon the vessel shape. • Capstons :Capston is thick revolving cylinder with a vertical axis, for

winding ropes, cables etc. This mechanism is used for controlling the ships, But only one rope can be used at a time. Two in the Aft side of port & starboard side of the dock. Steel wired ropes of 32mm diameter is rolled on the capston.

• Hauling carriage : It is a moving trolley inserted the both sides of special type rails permanently fitted at the top of the dock walls ( this trolley will move according to the pulling of the winch).This trolley contains four wheels, a hooks and a pulley. The hook will connect with the winch rope from dock side and the pulley with the help of ‘D’ shackle. We have to connect one steel and one nylon rope from the ship, as ship headline ropes

• Winches : Winch is used to control the ship while docking, centering & seating of the ship in the dock. Two permanent winches are fixed in the FWD end of the dock.

• Pontoon`s : 2 nos 9.5 x 9.5 M • Slave dock : 86 x 18 x 2.7 M • Barges : 17.5 x 7.5 M ( 50 T Fresh water barge) • Boat : MB-53-CP Shyala. Ashok leyland 80hp, Twin screw engine.

Capacity 15 persons without cargo. • Forklifts : 5 ton – 2, 3 ton – 2 • Cranes : OBE (40 ton) in starboard side of dock

TATA (10 ton) in port side of dock Quay2 – CAILLARD (10 ton) Quay1 – BRAITHWAITE (15 ton)

• Staging : As per the requirement, stages are put in the requested area. Before starting the work safety clearance is required. Hence with the availability of staging materials stages are put and when the work is finished, the materials are destaged and these materials are used for future staging activities.

Dock Services

o Putting Gangways o Fresh water lines o Fire lines o Cooling lines o Galley garbage removal o Placing and clearing the pallets from repair vessels.

Storing/disposal of dirty oil

Hull repair

Hull repair is the most extensive of all the ship repair processes. The process includes the following steps:

Survey& Identification

Ship will be taken under different types of surveys like:

• Annual survey- will be done in the interval of one year. It includes examination of ship side shell plating above water line, ballast tanks, openings on free board, water tight bulkhead penetrations etc.

• Special survey-

Special Survey No. I (Age of vessel < 5)

Requirements Annual hull Sy.

Examination of

All tanks including peak tanks

Engine and pump room Bilges

Special Survey No. II (5<Age of vessel < 10)

Requirements of Special sy.I to be complied with

Examination of Chain locker

Special Survey No. III (10<Age of vessel < 15)

Requirements of Special sy.II to be complied with

Wooden sheating areas on steel deck

• Docking survey- will be done in the interval of 2.5 to 3 years.

Identification includes Non-destructive testing (NDTs) like visual inspection, ultrasound thickness gauging, MPI, etc. and Destructive testing like chemical testing.

Preparatory jobs

They include both before and after docking jobs. Before the ship arrives grade of steel is identified, material positioning is done in Co-Ordination with SRM, blasting and priming of steel plates & sections, welding procedure and pre-fabrication. Once the ship arrives and is docked, lofting and scaffolding is to be done.

Blasting is the surface preparing process of spraying solids like copper slag, iron grit, granules, etc. with high pressure, dry air which helps expose the surface and gives it the surface required roughness for painting.

Safety precaution

Liasoning with Safety Dept for obtaining Man Entry & Hot-Work Permits

Deployment of Firewatchmen

Cropping- cutting out the defective plate sections which have been identified. It can be either mechanical or manual.

Preparation of new plate- using the measurements of the requirement, edge preparation according to the crop, plate forming (bending based on maxi loft mock-ups).

Fit up and fairing- based on standards, give temporary support to hold the plates in place and prepare before welding. We have to care about root gap and scallops

Inspection-which is done by the department from CSL and corresponding classes

o by CSL QC

Visual inspection

o by Class

Visual inspection

NDT

Welding- can be done by manual arc welding or CO2 welding.

Dry-Survey

Inspection- first done by CSL QC dept. by visual inspection and NDT.

Review of NDT by concerned Class.

NDT DURING REPAIR

After Welding, the Welding joint and inner defects are tested.

There are different types of testing:

1. Magnetic particle test: In this iron solution is sprayed on the weld joints. Electromagnetic machines magnetize the required part. Various contours are observed if there is any defect. Test is to be done by instrument called yoke, for magnetizing the material. Field indicator is tested before testing the portion as a reference. We can use this for surfaces, subsurface, interior portions etc.

2. X-ray test: Photograph of weld joint (especially pipe junction) is taken with a camera. The photograph is observed in X-ray machine in the dark room. The defects are clearly visible.

3. Ultrasound test: Ultrasound (having frequency more than 2000Hz) is passed through the plate. The echo is observed in receiver meter. The variation in echo shows the depth at which defect is present. The location can be found even in three-dimensional space.

4. Radiography test: In this gamma-rays are passed through material. The gamma-rays are allowed to fall on silver-bromide plated. A photochemical reaction takes place over this plate. If any defect is present, the reaction will be more; means the product (Ag) formed is more than expected. So the location in the plate where it is dark after the reaction corresponds to the defect location after development

ACCOMODATION REPAIR

Accommodation repair is an important part of repair as most of the human interaction takes place here. As such, accommodation safety and aesthetics have to be ensured. Accommodation includes:

Wheel House Cabins Offices Hospital Mess & Galley Game & Lobby

Accommodation repair involves: 1. Insulation 2. Ceiling and panelling 3. Flooring 4. Piping

INSULATION Insulation is important as it

Reduces Heat Transfer Provides Fire Protection Helps in Moisture Condensation

Helps in Noise Reduction There are various classes of insulation 1. A Class (Avg. 140 0C, Point 180 0C) : A-60, A-30, A-15, A-0 2. B Class (Avg. 140 0C, Point 225 0C) : B-15, B-0 3. C Class

Insulation Materials:

MFMB (Mineral Fibre Marine Board)

Glass wool

Rock wool

PUF (Poly Urythene Foam)

Panelling The purpose of panelling is to get

Good Appearance Good Finish Cleanliness Sound Proofing Heat Insulation Fire Proofing

Some common paneling materials that are used are: stainless steel, Aluminum sheet, Melamine faced pre-laminated board , Marine Plywood with Sunmica, Melamine Plastic Laminated Board (MPL), Sandwich type Board.

For paneling generally we have to fix channels first. Then fix the paneling then gaps should be filled with beadings. Aluminium and wood are commonly used beadings.

Flooring

There are four kinds of flooring involved: Macrotech, ceramic tiles, PVC tiles, wooden tiles.

In Macrotech the work involved are: surface preparation,primer apply, underlay, top coat, sealer coat.

In Ceramic Tiles, underlay, tiling, skirting, pointing are involved.

PVC tiles involve Underlay, tiling, skirting Wooden tiles involve Underlay (Syncolite), Sponge, Tiling, Polishing

Piping

Piping can be divided as follows

I. Sea Water System- these are the pipes for deck washing and toilet washing. for this cupronickel, copper or Aluminium –brass alloys are used

II. Fresh Water System- these are used for Mess & Galley, Toilets, Laundry etc. For this GI or copper pipes are used

III. Scupper Lines- used in deck and toilets. For this piping GI pipes are used

IV. Soil Lines

Miscellaneous Works

Deck Sheathing Cold Repair Carpentry Works Upholstery Works Awnigs

MACHINERY REPAIR

Machineries in a ship can be classified into:

• Engine room machinery-Main engines, Auxiliary engine, Boilers, Turbines, Pumps, Water makers, Heat exchangers, Pollution control equipment, Tail shaft ,Propellers and thrusters

• Deck machinery-Windlass anchor and anchor chain, Winches, Hydraulic pumps and motors, Deck cranes and derricks, Life boat and davit with accessories, Piping and valves, Crude oil washing system and inert gas systems

• Pump room machinery-Centrifugal Pump, Reciprocating Pump, Vane Pump, Gear Pump, Screw Pump, Diaphragm Pump These equipments should be tested and repaired if there is any damage. Procedures for over hauling of main engine or auxiliary engines are given as

follows: Decarbonising. Remove Cylinder heads Remove Pistons Remove Liners Cleaning Calibration Inspection and Survey Remove Bearings Clean and calibration Present for Survey Renewal if Required

Shaft and propeller repair is also included in this department, and this includes Fixed pitch propeller (can be keyed or keyless propeller) and Controllable pitch propeller, etc. For propeller maintenance propeller blades and hub should be removed and refit by manual push up, by pilgrim nut or by hydraulic system after maintenance and cavitation prevention. For controllable pitch propeller, blades and hubshould be removed. Blade seals should be renewed. After filling oil, hub should be refitted with blades. Tail shaft repair is done along with propeller maintenance. For this, the tail shaft and propeller is removed. Stern tube oil is drained and forward and aft seals are removed. After that, Intermediate shaft and fitted bolts are removed. The internal shaft is then lowered .Tail Shaft and Stern tube Bushes are cleaned and calibrated. After presenting for survey, stern tube brushes and shaft seals are renewed as per requirement. Rudder machineries (steering machineries) , pumps (centrifugal Pump, Reciprocating Pump, Vane Pump, Gear Pump, Screw Pump, Diaphragm Pump

etc),valves(globe valve, gate valve, piston valve etc.), air compressors ,Boilers, turbines, heat exchangers, pollution control equipment etc. are tested and repaired.

• Rudders are of two types- Vane type and Ram type. The former Vane type uses motors (mechanical or electric) to turn the shafts while in the latter Ram type uses hydraulic rams (i.e., long piston like rods) to push the rudder shafts in required direction. Maintenance has to be done here to the motors, shafts, or the rams as required.

• For the pumps, repair work will be required for the impellers, wear and piston rings, shafts, seals, casings, packing, bearings, etc depending on the type and variety of it.

• The procedure for Air compressors’ repair is: Removal of Heads and Pistons, Cleaning and Calibration, Presenting for survey, renewal of parts required and then, assembling and trials.

• Boilers are used for steam pumps, cargo oil turbines, accommodation heating during winters, etc. For Boilers and heat exchangers: Changing refractories and end covers, furnace or tube cleaning, burner overhauling, safety valves, and boiler mounting, re-tubing and pressure testing.

• Among deck machinery, major repair works are required and done for windlasses and deck cranes. Windlasses can either be hydraulic operated or electric operated. For windlasses, they must be overhauled and repaired. In the case of deck cranes, the process would include overhauling of pumps, pulleys, gearbox and motors, changing of brake liners and wire ropes, load test, etc.

ELECTRICAL REPAIR

Each ship contains different electrical based plans and diagrams such as block diagram, system diagram, circuit diagram, wiring diagram and connection diagram. Electrical repair includes various tests like tests for Insulation resistance (using megger), current (clam meter), voltage, resistance, and continuity (multimeter). Generator protection includes from overcurrent, short circuit, under voltage, reverse power, preference tripping, and winding temperature. There are different classes for the protection and insulation of materials. The insulation class includes: class Y: 90, class A: 105, class E: 120, class B: 130. The

protection class is denoted by “IP XY”. The major equipment on-board a ship that requires electrical repair include motors, lights, switchboards, wiring, etc. For motors, its rotor resistance, drive and frequency are checked.

Different types of lamps used are Incandescent lamps, high or low pressure vapour lamps (mercury or sodium), metal halide lamps, etc. They are used in accommodation areas, machinery area or for navigational light purpose like mast lights (fore mast or main mast), port and starboard side lights (red and green), stern light (white), anchor lights (fore and aft) or Morse code flashing lights.

The electrical repair work is also dependent on the area of activity and the hazard classification due to presence of gas- air mixture in certain parts. Prior to the electrical repair, survey is taken. Some of the equipment a typical electrical survey would require includes:

• Generators and Governors • Circuit Breakers • Switchboards, Cables and Fittings • Insulation and resistance • Motor and Starters • Emergency Power Equipment • Steering Gear • Navigation Lights & control Panel

PAINTING

Painting is done mainly for the following purposes

• Corrosion prevention • Aesthetic • Frictional resistance reduction –by keeping hull as smooth

In ship repair the blasting is done under painting department. Blasting is done to make surface profile. Surface profile is done, so that the paint can easily stick to the surface of the material. Before blasting, surface should be cleaned to remove deposits. Iron shorts or copper slag are blasted with high pressure over the surface.

Quality of blasting is depends on standard abrasive (SA) like SA1, SA2 etc. the following are the blast cleaning techniques which can be used

Centrifugal blasting Sand injected water blasting Slurry blast Wet abrasive blast Dry grit blast cleaning etc.

Main parts of the blasting equipment: -

air supply hose, blast abrasive hose, copper slag tank, coupling part.

Pressurized air will be supplied from main compressor area at 6Kg/m3.copper slag will be supplied from tank. Both will couple and ejected through blast abrasive hose with high force.

1 coat of primer should be applied after blasting to avoid sudden corrosion. After completing the repair, the painting procedure is as follows

Primer-50 microns Anticorrosive -150 microns- 2 coats Tie coat- 100 microns Antifouling-150 microne-6 coats

After these coatings we will give sacrificial anodes (Zn)for preventing corrosion of the plates.

Protective coatings

There are three types of protective coatings to prevent the corrosion by contact of sea water

Sacrificial coating-they are rich in Zn content. They will be oxidized instead of plates Barrier coatings-these coatings will keep the surface as moisture free Inhibitive coatings-it is used only as primers

Coatings can be done by either by conventional spray or by airless spray in which hot spray, electrostatic spray, centrifugal spray etc. methods are used as required.

Few of the methods are given below

Plural component spray Hot spray Electro static spray Centrifugal spray

HVLP spray Air assisted airless spray

Types of the paints in different parts of the ship will be different according to the use and environmental conditions. for example paints which applies at ballast tank will be different from paint at fuel oil tank.

There are mainly two types of defects which have to try to avoid as much as possible to prevent fast corrosion they are

• Design defects – riveted and bolted constructions, gapes between two members, sharp edges, corners (exterior and interior), overlapping plates etc.

• Fabrication defects – imperfect welding (weld spatter, skip weld, rough weld etc.), laminations, sharp corner and edges etc.

MACHINE SHOP

Machining Operations

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Machines Available

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