Development of Floating Vehicles and Structures

Major developments in Marine Field

Early years – logs, wooden boats, ore propelled boats and sailing boats – inland water as well as sea – Building of boats was by traditional skills and innovations were mainly in the form of the boat – That is why the art of shipbuilding (and ship design) was called Naval Architecture.

1780 to 1810 – Steam engines in ships – birth of Marine Engineering as a professional skill. Sail is replaced by coal for energy.1800s – Use of paddles and screw propellers on ships.1837 to 1858 – 1 K Brunnel built GREAT EASTERN, GREAT WESTERN and GREAT BRITAIN 1820 to 1880 – iron ships and composit ships 1880 onwards – steel ships1900 onwards – oil replaces coal as ship energy source.1920 onwards – welding in ship construction1892 – Invention of diesel engine1912 onwards – use of diesel engine in ships1954 – First nuclear ship Nautilus1906 – First hydrofoil1955 – First jack – up drilling unit built1959 – First practical hovercraft1958 – First time carriage of LNG by sea1919 to 1938 – Ship types begin to appear – cargo liners, tramps, ore carriers, tankers. Full flowering of passenger liners.1945 to 1955 – post war replacement. Modest technical advance. Large number of cheap ships – cargo – built, eg. FREEDOM class vessels.1955 to 1965 – Ship size and speed increase advent of modern scientific design practices. 1965 to 1973 – Golden age of shipping – container ships, ro-ro, car carriers, chemical and gas carriers. Ships increase in size – economy of scale – VLCC and ULCC built. Demise of passenger transport by sea.

Scientific procedures advance – structural design, new production techniques etc.

1973 to 1982 – Rise in oil price, large tankers fade away. Improvement in diesel engines for better fuel efficiency, slow steaming of vessels

1970 onwards – offshore oil exploration and extraction in commercial scale – offshore platforms of various kinds are designed and built – a new of Ocean engineering appears on the academic scene. Ocean is seen as a store house of resources. Extraction of minerals living resources and energy – research in these areas start.

1990 to 2000 – Sea as the Common Heritage of Mankind – Law of the Sea promulgated.

Present trends in Technology

SafetyPollution preventionComputers and ITCargo handling EfficiencyFuel Alternatives and Efficiency Structural EfficiencyManning standards and levelsScientific analysis – CFD, FEM etc.Management practices – ISO, ISM, TQM etc Dismantling

Sizes of Cargo Ships

Mini Bulkcarriers: < 10000t dwtSmall Handy Size carriers, 20000 to 28000 t dwtHandy Size carriers 28000 to 40000 t dwtHandymax carriers 40000 to 50000 t dwtSeawayMax the largest size that can travel the St. Lawrence Seaway(B <= 23.16m)Aframax tankers: 75000 to 115000t dwt Suezmax: Largest Vessel passing through Suez Canal – upto 150000t dwtPanamax: Largest Vessel passing through Panama Canal (B <= 32.2 m) –

65000 to 80000t dwtMalaccamax: Strait depth 25m - VLCCsCapesize: Vessels navigating across Cape of Good Hope and Cape Horn

(bigger than Suezmax and Panamax) – 80000 to 120000t dwtVLCC (very large crude carrier) super tankers of 150000 to 320000t dwtULCC (ultra large crude carrier) super tankers of 320000 to 550000t dwtVLBC (very large bulk carrier) upto 200000t dwt carrying capacity

CLASSIFICATION OF MARINE VEHICLES & STRUCTURES

Marine Vehicles and StructuresInland Waterways

Propelled (Barges, Tugs, passenger boats, Fishing Boats etc.)Non-Propelled (Barges, Dredgers etc.)Pleasure (Restaurants, tourist boats – paddles, oars, motor

boats, planing boats, house boats)Sea going

TransportIndustrial Vessels (owner operated)

Fishing VesselsSupply VesselsShips for industrial houses

General Cargo Break Bulk

General Cargo/ Multipurpose vesselsCargo liners

UnitisedContainer shipsBarge carriersRORO vessels

Passenger VesselsFerriesCruise ShipsPassenger ships Fast Transport Vessels

Dry BulkBulk CarriersOre CarriersCombination Carriers (OBO etc.)

Liquid BulkCrude oil carriersProduct TankersChemical TankersCryogenic Vessels (LPG/ LNG/ Ammonia)

Non-TransportService Vessels

TugsDredgersSupply VesselsIce BreakersResearch Vessels

Military VesselsOffensiveDefensiveSubmarines and SubmersiblesSupport Vessels

IndustrialOil Exploration and Production platformsOil Storage and OffloadingOil Transportation (Tankers, LNG, Pipe lines)Ocean MiningOcean energyFloating Airport

OthersTourism and sports

Planing/ Hydrofoil vesselsSES/ HovercraftHybrid vesselsYatchesFloating Tourism Facilities

General Cargo ships

Characteristics

Number has gone down with increase in specialised ships such as continer ships and RORO ships.

Liners - sophisticated ships with high speed of upto 20 knotsTramps – cheap ships of ‘workhorse’ type calling at medium and small

portsMulti deck ships – more floor space for cargoHold sizes and hatch sizes for variety cargo such as containers and large

steel products. Hatch width < B/2 for single hatch ships or , 0.75B for twin or triple hatch ships.

Cargo handling by cranes/ derricks vertically with atleast one heavy lift crane

Standard Designs – Mariner Class, Freedom Class and Fortune Class

Stowage Factors of general cargo

Stowage FactorCommodity Packing m3/metric Ton (ft3/Long Ton)

Alcohol Drums 1.89 (68)Caraway Seed Bags 1.50 (54)Cement Sacks 4.18 (150)Hides (wet) Bundles 1.23 (44)Hides (dry) Bales 5.57 (200)Structural Steel Beams Piece 0.67 (24)

STANDARD CONTAINER SIZES

metric Imperial Metric imperial metric

external dimensions

length 20′ 4″ 6.198 m 40′ 0″ 12.192m 45′ 0″ 13.716m

width 8′ 0″ 2.438 m 8′ 0″ 2.438 m 8′ 0″ 2.438 m

height 8′ 6″ 2.591 m 8′ 6″ 2.591 m 9′ 6″ 2.896 m

interior dimensions

length 19′ 4 13/16″ 5.898 m 39′ 5 45/64″ 12.032 m 44′ 4″ 13.556 m

width 7′ 8 19/32″ 2.352 m 7′ 8 19/32″ 2.352 m 7′ 8 19/32″ 2.352 m

height 7′ 9 57/64″ 2.385 m 7′ 9 57/64″ 2.385 m 8′ 9 15/16″ 2.698 m

door aperture

width 7′ 8 1/8″ 2.343 m 7′ 8 1/8″ 2.343 m 7′ 8 1/8″ 2.343 m

height 7′ 5 3/4″ 2.280 m 7′ 5 3/4″ 2.280 m 8′5  49/64″ 2.585 m

volume 1,169 ft³ 33.1 m³ 2,385 ft³ 67.5 m³ 3,040 ft³ 86.1 m³

maximum gross mass 52,910 lb 24,000kg 67,200 lb 30,480kg 67,200 lb 30,480 kg

empty weight 5,140 lb 2,330 kg 8,820 lb 4,000 kg 10,580 lb 4,800 kg

net load 47,770 lb 21,670kg 58,380 lb 26,480kg 56,620 lb 25,680 kg

Container Ships

Standard size – TEU and FEUDoor to door transport/ Intermodal transportLiner Service – fixed ports with scheduled serviceFreight rate is high – container conferences for freight stabilisationFine form High speed shipsHub ports and large container ship movement between hub portsContainer ship sizes have gone upto Feeder service – ships having 250 tp 1200 TEU capacity over small distanceTheoretical size – Suezmax: 14000 TEU, 137000 dwt, 400m x 50m x 15m(T), 85MW, 25.5 knotsMalaccamax: 18000 TEU, 300000 dwt, 470m x 60m x 16m(T), 100MW, 25.5 knots

Container stacking Arrangements:Locking with each otherLashing to double bottom, deck or bulkheadsCell guides

Cellular Container ShipsOpen Hatch Container ShipsStability (high CG)Motion (High acceleration for top containers)High Torsional Stress (Box Girders)Cargo Handling (geared/ gearless)No Ballast Voyage

Ten Biggest Container Ship Classes, listed by TEU capacity

Built NameSister

ships

Length o.a.

BeamMaxium

TEUGT Owners Flag

2006 Emma Mærsk 4 397.7 m56.4 m

14,500 151,687 Maersk Line Denmark

2005Gudrun Mærsk

5 367.3 m42.8 m

10,150 97,933 Maersk Line Denmark

2006Xin Los Angeles

6 336.7 m45.6 m

9,600 [2] 107,200 CSCLHong Kong

2006Cosco Guangzhou

4 350 m42.8 m

9,450[3] 99,833 Cosco Greece

2006CMA CGM Medea

3 350 m42.8 m

9,415[4] 99,500 CMA CGM France

2003 Axel Mærsk 5 352.6 m42.8 m

9,310 93,496 Maersk Line Denmark

2006 NYK Vega 2 338.2 m45.6 m

9,200 97,825Nippon Yusen Kaisha

Panama

2005 MSC Pamela 5 336.7 m45.6 m

9,178 90,500 MSC Liberia

2006MSC Madeleine

1 348.5 m42.8 m

9,100 107,551 MSC Liberia

2006Hannover Bridge

2 336 m45.8 m

9,040 89,000 K Line Japan

Barge Carriers

Intermodal Transportation – sea and riverStandard Barges – SEABEE Barges

LASH Barges BACAT Barges

Very Heavy Cargo Handling Gear –SEABEE ship has a barge elevator 31.8x23m to lift two barges, one on

top of the other, total capacity being 2000t operated by hydraulic power pack, winches, sheaves, wire ropes etc., the total equipment weighing 540 t.

LASH vessels have either gantry cranes of 500t or 300t, or elevating platform of SEABEE vessels.

BACAT vessels have gantry crane/ elevator of 300 to 400t capacity

Ferries and Passenger Vessels

High capacity cargo, large volume required for carrying passengersCostly cargo with high freightLiner service – scheduled serviceNumber of Superstructure decks extending from fore end to aft endHigh CGMuch better habitability, manoeuvrability and stability requiredHigh breadth, low draught, fine form, high speed Facilities depending on passenger standardShot distance – ferries with no sleeping accommodation or minimum sleeping accommodation, lower decks may be car dedks operated as roro vessels withstern/ bow rampsLong distance – luxury liners with a number of recreational facilitiesLong distance – cheap travel for pilgrimage or main land to island travel – dormitory to deluxe accommodation with limited commom spacesHigh performance vehicles to move passengers over short distances quickly –

Catamaran fast ferriesPlaning Vessels – mono hull and catamaransHydrofoil Boats – surface piercing or fully submergedSES and HovercraftsHybrid vessels combining planning, foil and/ or aerostatic pressureUse of Wing in Ground Effect (WIG) to move fast

RORO Vessels

Bow doors with internal rampTransom/ stern doors serving as rampsSide portsInternal ramps, elevators to move cargo to other decksEquipment to lower/ raise and swivel ramps include wire ropes/ chains, winches and sheavesRamps become heavy based on weight of vehicles moved on themUse – passenger ferries (cars), Cargo ships (horizontal loading) and

RORO vessels (containers on trailers)Liner – scheduled – service, high freight rateHigh volume requiredHigh speed, fine form, large breadth, low draught vessels with high manoeuvrability to reduce port turn around timeDue to horizontal movement of vehicles, transverse WT partitioning is compromised. SoStability in damaged condition is a critical design requirement

Dry Bulk Cargo Ships

Characteristics

Volume / weight based design – deadweight carrierSingle deckBottom sloping tanks for easy cargo handlingAngle of repose and grain shifting – top side tanks / shifting boardsAlternate hold loading – BM and SF ProblemHeavy bulk carriage – ore carrier with high double bottomMultiple cargo carriers - OBOsSlow speed vessels – full form, stern flow – wake control Automatic/ Otherwise Loading / UnloadingSize has gone on increasing – Panamax, Suezmax, Aframax and VLBC

Typical Bulk Cargoes

Commodity Stowage factor, ft3/long ton Stowage factor, m3/long ton Specific gravity, ton/m3

Iron ore 12-15 0.34 – 0.42 3-2.42Coal 42-48 1.2-1.36 0.85-0.75Grain heavy 42-56 1.2-1.42 0.85-0.72Grain light 55-60 1.56-1.7 0.65-0.6Bauxite 28-35 0.79-0.99 1.29-1.03Phosphate/rock 33-34 0.91-0.96 1.12-1.06General 24-29 0.69-0.82 1.47-1.24

Crude Oil Tankers and Product Tankers

Before 1970s Tanker Characteristics:Single Hull simple construction shipCheap Cargo, deadweight oriented, Type A FreeboardSafe ship both from damaged stability and structural point of viewTanker size went on increasing from 1950 onwardsIn 60s we had VLCCs and ULCCs designed, built and operatedGolden age of shipping new analysis techniques evolved and used in design – FEM and flow methods

Early 1970sArab-Israel WarOPEC formed and Very high increase in oil priceOil trade and hence Tanker market collapsedVLCCs and ULCCs operation stopped and building contracts cancelledCollapse of European shipbuildingExisting VLCCs and ULCCs utilised for oils storage at sea/ portOil price went on increasing over 70s and 80sTanker size reduced drastically

SimulteneouslyTanker Disasters and Pollution of Coast linesLed to Marpol in 1978 and modifications later onEquipment for monitoring bilge oil content and oil removal from waterDesign guide lines for oil and BW tanksOil cargo in Protective Locations

PresentlyTankers of moderate size going upto about 150000 t dwt Single deck, deadweight carrierComplete Double HullBW and cargo/ oil saggregationEquipment for pollution control, sludge control and fire controlStability is important in fully loaded conditionSlow full form shipsLarge space allocated to BW and so, impossible to achieve Type A freeboardWake and stern flowCargo Handling by Cargo and Stripping pumps and pipelines on boardProduct and chemical tankers to have compartments marked for each product and Each product must have separate handling system

Tanker Arrangements

Liquified Gas Carriers

LNG, LPG, Ammonia etc.

Carried either at (i) Normal temperature and high pressure or (ii) Cryogenic temperature at normal pressure (this is more common)

Cargo carried in special tanks (i) Membrane Tanks (integral with the ship hull)(ii) Spherical tanks

Tanks – inner wall is of non-corrosive material to withstand cargo imposed conditions (normally stainless steel)High Technology VesselsTanks, pipelines etc are heavily insulatedCare to be taken to see that joints etc. do not crack due to uneven expansionCare to be taken to ensure no leakage of cryogenic material on normal steel structureBoil-off gases – can main engine use it?Fire fighting – nitrogen shielding