Shipbuilding & Ship Repair Industry in the Indian Subcontinent

Introduction to Oil Tanker Design for Indian Oil Corporation Ltd.

Presented by Nikhil Raj,GM (SB&S)1DefinitionOil Tanker - Oil tanker means a ship constructed or adapted primarily to carry oil in bulk in its cargo spaces.Categories Crude Oil Tanker- Product Oil Tanker 2Type of Hull ConstructionSingle Hull Tankers These vessels have side shell/ bottom shell as a common boundary between cargo tank and sea Double Hull Tankers Double hull tankers are so designed that the cargo tanks do not have side shell as a common boundary. The space between the side shell and cargo tank is generally used for ballast.

Note: IMO Phase out date for single hull tankers is 2015 or 25 years age, whichever is early

Oil Tanker ClassificationGeneral Purpose: 10,000 T 24,999 T DwtMedium Range: 25,000 T 44,999 T DwtLong Range 1 : 45,000 T 79,999T DwtLong Range 2: 80,000 T 159,999 T DwtVLCC: 160,000 T 319,999 T DwtULCC: 320,000 T 549,999 T Dwt

Oil Tanker Classification Product Tanker: 10,000 T 60,000 T DwtPanamax: 60,000 T 80,000 T DwtAframax: 80,000 T 120,000 T DwtSuezmax: 120,000 T 200,000 T DwtVLCC: 200,000 T 315,000 T DwtULCC: 320,000 T 550,000 T Dwt

Oil Tanker DesignFactors to be considered for an Oil Tanker Design: Market requirements. Regulatory requirements e.g. SOLAS, MARPOL, etc. Classification Society Requirements. Port/ Terminal Requirements e.g. draft, size, mooring, etc. Oil Major Requirements. Flag State Additional Requirements, if any. National/ International Standards. Special areas Requirements e.g. ECAs Owners extra requirements Oil Tanker DesignMain Parameters Dimensions (Length/ Breadth/ Depth/ Draft) Speed Power of Main Engine Dead Weight Cargo Capacities

Cargo Tank Arrangement

CargoTank Arrangement on VLCC

Oil Tanker DesignClass Requirements for Hull Design All Oil tankers of Length more than 150 m are required to comply with the Common Structural Rules (CSR) of IACS. Vessels of length less than 150 m are required to comply with the requirements of individual Classification Societies. Design life of 25 years is considered for all Oil Tankers built to CSR. The design life of tankers not complying with CSR is 20 years unless it is specified higher.

Midship Section of Panamax Tanker

Midship Section of a VLCC

Painting of Cargo Tanks As per new SOLAS amendments Regulation II-1/3-11, all new crude oil tankers of 5,000 dwt or above engaged on international voyages are required to comply with Performance Standard for Protective Coatings for Cargo Oil Tanks as per following schedule: Contract date: 1 January, 2013 Keel laying date: 1 July, 2013 Delivery date: 1 January, 2016 The target life of coating system is 15 years. All vessels are required to maintain a Coating Technical File for Cargo tank coatings endorsed by Class. All tank coatings shall be type approved as per IMO.Oil Tanker DesignMooring Arrangement is very critical requirement for an Oil Tanker. It is normally guided by the Oil terminal requirement which is higher than the Classification Requirements.

All oil tankers have to comply with OCIMF guidelines on mooring vessels at Oil terminals, Single Point Moorings and Double banking/ STS transfer. Typical Mooring Arrangement at a Berth

Single Point Mooring

Ship to Ship Transfer Operation

Cargo SystemDesign of Cargo System depends upon the number of different grades of cargo to be loaded simultaneously i.e. 3 or 4 grades.All segregations are to be double valve as per OCIMF.Vessel to be provided with Cargo Manifold as per OCIMF guidelines.Vessels fitted with Pump room are required to comply with OCIMF paper on Pump Room Safety.Product Tankers may be designed without pump room. Cargo SystemIn case of emergency during adverse weather condition, vessel can load water in a designated cargo tank. A separate sea suction is provided for the same in the pump room with valve testing arrangements.Connection is also made between ballast and cargo system for emergency de-ballasting using cargo pumps.All overboard discharge from cargo tanks must be led through an approved type Oil Discharge and Monitoring Equipment. Cargo Pumping SystemCargo pumping system consists of cargo pumps, tank cleaning pump, stripping pump and cargo eductors. Steam Turbine driven cargo pumps are generally provided for cargo pumping system in bigger tankers.Electric driven cargo pumps are provided mostly on small tankers.The prime movers are placed in safe zone inside the engine room.Product Tankers up to Panamax size may also be provided with submerged type cargo pumps fitted in each tank.

20Cargo Manifold Arrangement

Tank Cleaning SystemA separate tank cleaning system is required to be provided on the vessel to carryout tank cleaning/ Crude Oil Washing (>20,000T Dwt).The tank cleaning system consists of fixed tank cleaning machines, submerged tanks cleaning machines and portable tank cleaning machines.The number of tank cleaning machines for each tank is decided based on the shadow diagram. Vessel is required to carry out Crude Oil Washing of 25% of the tanks during each discharging operation.Hot Water washing of the cargo tanks is carried out at the time of layup using a tank cleaning heater. Safety MeasuresThe cargo inside each tank is carried in an inert environment.Gas sampling system is provided for double hull spaces and void spaces (20,000T Dwt & above) in the cargo area & pump room for vessels fitted with pump room.Accommodation air conditioning air intake is also provided with gas detection system to avoid oil vapours entering the accommodation areas. Cargo deck is protected by Foam type fire extinguishing system. Emergency Towing Arrangements are required to be provided at both forward and aft end of Tankers of Dwt > 20,000 T as per SOLAS. Emergency Towing Procedure Manual to be kept on the vessel.Safety MeasuresSafe Access to Tanker Bow as per SOLAS II-1, Reg 3-3.Permanent Means of Access inside Cargo Tanks as per SOLAS II-1, Reg 3-6. All Tankers are required to be provided with Ship Structure Access Manual.Venting arrangement for cargo tanks.- Mast Risers (30m/s) - Primary- Pressure/ Vacuum Valve (20m/s) Secondary 1.25 the tank loading rate - Pressure sensors (Alternative)- Design capacity 1.25 times the loading rate of cargo systemVenting of Pump Room : 20 air changes/ hrCargo, Ballast and Stripping Pumps for bulkhead shaft glands, bearing and casing - audible & visible alarm/tripsLighting in Pump room to be inter-locked with the ventilation system such that the ventilation is in operation when switching on the lights.Safety MeasuresPump room to be provided with bilge level monitoring devices with alarms in CCR.Fixed fire extinguishing system for pump room.Vibration monitoring of Cargo pumps and Ventilation fans.Cargo pump gland seal leakage alarm in CCR.

Safe Access to Tanker Bow

Mast Riser/ Vent Riser

Pressure/ Vacuum Valve

Inert Gas SystemAll new Oil Tankers of Dwt > 8,000 T are to be fitted with an Inert Gas SystemCrude Oil Tankers are provided with Inert Gas Plant based on flue gas generation in the Aux. Boilers.Product Tankers are provided with Inert Gas Generating plant burning Diesel Oil to avoid cargo contamination.Maximum Oxygen content in the tanks are maintained at 8% in the cargo tanks and 5% in the IG line as per rules.Vessels are also provided with vapour manifold as per USCG/ OCIMF requirements to return vapour to the shore facilities during loading/ unloading operations.Gas freeing of the cargo tanks is carried out by passing fresh air to the cargo tanks using IG Fans and releasing the cargo vapours in the air through vent risers/ opening gas freeing covers fitted on each tank or provided separately in the cargo piping system.29Pollution Prevention MeasuresDouble Hull Construction.Segregated Ballast (>20,000T Dwt & above). Pump room is provided with double bottom.Oil Spill Coaming/ spill tray provided for containment of oil spill on deck and manifold.Ballast System pipes, air vent pipes, sounding pipes of ballast tanks should not pass through cargo tanks and cargo pipes should not pass through the ballast tanks.Slop tanks to retain tank washings, deck spill, dirty ballast.Vessel to be provided with approved type Oil Discharge and Monitoring Equipment as per MARPOL.

Cargo Monitoring SystemCargo level gauging system combined with pressure sensors and monitored in the CCR. High/ High Alarms in CMS monitored in CCRClosed ullage system for manual ullage measurement.Hand dipping posts.Overfill alarm.

31Role of Classification SocietyDevelop Rules for design andconstruction of ships.Approve designs against their Rules.Conduct surveys during construction to satisfy the ship is built in accordance with the approved design and to the requirements of the Rules.Acts as a Recognised Organisation carrying out statutory surveys & certification as delegated by maritime administrations.Regulations for in-service inspection and periodic survey during operation.Research and development programmes.Support international organisations IMO,ISO,IACS.

32Preparation of Merchant Shipping Rules related to Crew Accommodation, Safety Construction of Vessel, Life Saving Appliances, Fire Fighting Appliances, Pollution Control, Collision Prevention, Radio Rules, etc.Ensures compliance with Statutory requirements.Final Approving authority for compliance with RulesGuides Shipping Industry on application of Rules

Role of Director General of Shipping 33Thank You

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