OTM-7.20	Oil Tanker Manual OTM Miscellaneous Operations	Doc No.: OTM 7.20 Revision: 01 Date: 15 Oct 2024 Issued by: DPA Approved by: MD

1. APPLICATION

This document applies to the Master, Chief Officer, and Chief Engineer onboard fully managed Tank vessels.

2. PURPOSE

To specify standard requirements for tanker operations.

3. RESPONSIBILITIES

• Master: Ensure vessel is safely afloat during cargo operation.
• Chief Officer:
  • Ensure stability criteria are met.
  • Ensure correct operation of VECS.
  • Comply with company policy for all special operations.
  • Train junior officers.
• Chief Engineer: Ensure proper running of engine room machinery to avoid excessive smoke emission.

4. STABILITY PRECAUTIONS

Free surface effect results in loss of stability on double hull tankers without center line bulkhead. This may lead to:

• Negative GM
• Angle of loll
• Damage to ship structure & property

To prevent such accidents officers to familiarize with stability criteria:

• During cargo operations
• Ballasting & de-ballasting with
• Special attention during simultaneous operations in port
• Vessel restriction on number of slack tanks

Restore stability in coordination with terminal. Consider the following:

• Lower vertical center of gravity.
• Fill slack tanks, starting from lowest point.
• Consider filling empty tanks.
• Do not attempt to fill up tanks on higher side.
• Consider adjusting mooring ropes.
• Keep minimum slack tanks.

5. CARGO VAPOUR EMISSIONS CONTROL

Vent out volatile cargo vapours during loading using approved venting system. Use vapour emission control system (VECS) whenever required by local regulations. Ensure the following on ships fitted with VECS:

• Regular training of crew on operation of VECS.
• Training prior to arrival at port.
• Maintain all training records.
• Approved VECS operation and training manual.
• Do not mix vapours of incompatible cargo.
• During STS operation ensure tanks are inerted on both ships.
• Test the system no more than 24 hours prior to arrival.
• Use certified hoses during vapour balancing.

Refer to OTM 7.4 for alarm settings.

6. SMOKE STACK EMISSION

• Monitor smoke stack emission using Poster 007.
• Inform engine room as required.
• Ensure compliance with MARPOL Annex VI for use of correct fuel.

7. SPECIAL OPERATIONS

Guidance is given for the following operations:

Addition of Dye/STADIS and Fuel Additives

Addition of Dye or any Fuel Additive is a special operation that must be exercised with care. Following are the minimum requirements that must be fulfilled before carrying out any such operation:

• Risk Assessment should be carried out.
• Owner’s approval to be taken to carry out this operation.
• Compatibility of the additive with cargo tank coating should be verified.
• LOI to be obtained from Charterer to indemnify owners against any claim which could occur due to these operations (cargo contamination, etc.).

For Tank Cleaning with Part Cargo, Commingling, Load on Top & Line Sharing

The following minimum documents are required:

• Risk assessment
• Owner’s approval
• LOI from charterers

Flushing of Shore Line using Sea Water

In case the flushing operation involves the use of sea water using the ship’s pumps, this can be done in the following three ways:

• By taking sea water in the cargo or slop tank using the tank cleaning line or any similar arrangement, and then pumping this water ashore using the ship’s cargo pump.
• By filling up the cargo or slop tanks with water taken through the cargo sea chest, and this water can be pumped ashore using the ship’s cargo pump. If any cargo or slop tank is empty, water should preferably be filled before entering port.
• By directly pushing the water ashore by taking suction from the cargo sea chest. This method is least preferred due to the risk of cargo going out of the sea chest while the vessel is in port.

Any operation involving opening of cargo sea chest will require extreme care and risk assessment to avoid any cargo from going out from the sea chest.

First, the cargo pump must be started to build up vacuum in the sea chest before opening the sea chest valve. A LOI must be taken from the charterer before carrying out any line flushing operation using sea water.

A LOI must be obtained from the charterer, if the vessel’s cargo hose is requested to be deployed at the manifold for cargo loading/discharging. This is not necessary if cargo hoses are utilized for cargo tank interconnection/line up.

Clearing of Shore Line by Pigging Operation

To avoid possible future troubles, the cargo quantity for flushing and whether such flushing is to be stopped by ship’s order or by shore order needs to be confirmed.

To prevent flushing cargo from entering irrelevant tanks by erroneous operation, the tank numbers to be flushed, sequence of operations, valve handling operations, and other important matters should be conveyed to all crewmembers concerned by posting such instructions in the control room.

Appropriate allocation of crewmembers and means of communication between the deck and the control room should be determined beforehand for smooth operations.

If the line clearing operation involves pigging or blowing of lines from the terminal to the ship’s tanks, the following precautions must be exercised:

• Avoid using tanks that are loaded close to 98% as reception tanks for line clearing.
• Add a safety margin when estimating required ullages for reception tanks to account for inaccurately declared “pigging quantities.”
• Consider including provisions for a standby cargo tank to be lined up and ready to be opened.
• Keep manifold valves closed during idle periods.
• Ensure that the vapour return line to shore is open during the operation (when available).
• Keep a close watch on the pressure inside the cargo tank to ensure that the tanks do not get over-pressurized.
• Throttle the main manifold valve as required.
• Monitor the manifold pressure closely.
• Monitor the available amount of cargo tank ullage space and pressure in the tank.
• During freezing weather conditions, inspect tank vents (P/V valves) at regular intervals.
• Close manifold valves immediately (in agreement with the terminal) once a pig has reached its receiver/trap, to avoid compressed propelling gas entering a loaded cargo.

Doping and Additives: Anti-static, Inhibitors, Dyes, Hydrogen Sulphide Knockdown

Doping is when cargoes are treated with small quantities of specialized additives and fluids, such as dyes, liquid market, anti-static agents, and lubricants, during loading or before leaving the port.

As far as possible, doping should be carried out ashore or in a closed in-line condition. When the cargo or additives are flammable or toxic, a closed doping operation is recommended. However, some terminals do not have a closed in-line additives injection system, so the additives have to be added manually. Any manual doping activity should be risk-assessed. Appropriate procedures should be in place to control the associated hazards. Manual doping operations should be carefully planned to minimize the health, safety, and environmental impact.

The associated risk assessment should include a review of the Safety Data Sheet (SDS) of the cargo and the additives, suppliers’ instructions, PPE, physical and operational hazards, supervision, weather, equipment, resources, and contingency measures. Any free fall of additives into non-inerted cargo tanks should be avoided.

The suppliers/contractors should draw up a doping plan and communicate this to the ship’s Master before any doping. On receiving the Plan, the Master should carry out their own onboard risk assessment and check that all the relevant items have been addressed and the risks reduced to As Low As Reasonably Practicable (ALARP).

Types of Cargo Additives

• SDS should be reviewed for flammability and toxicity information.
• Required PPE and handling equipment should be identified and made available.
• Storage requirements for any additive to be carried on board.
• Considerations for any spillages during the operation and method of clean up.
• Requirements for diluting the additive prior to doping.
• Confirm the tank coating is compatible.

Method of Doping Under Consideration

• Preference is for injection at a shore location or via an in-line injection system (e.g., via a spool piece at the ship’s manifold):
  • Pressure test records for the injection system should be verified prior to commencing cargo operation.
• Where injection is required via a cargo tank vapour lock:
• No doping should be undertaken on a live (loading) tank.
• Personnel undertaking the operation should stand upwind of the tank opening to minimize gas exposure.
• PPE is required to be fully implemented including use of a personal gas monitor.
• Anti-static precautions are to include ensuring the doping pump/container is properly grounded and the hoses are of an anti-static type.
• Doping should only be undertaken one tank at a time.
• When the ship has IG:
• The tank branch line should be shut, and the tank depressurized prior to doping.
• After the doping operation, the tank oxygen content is to be reconfirmed and the tank re-pressurized.
• When the ship does not have IG:
• Free fall of additive into the cargo tank is prohibited.
• When no full-depth sounding pipes are provided, a minimum 30-minute relaxation period is required before and after the addition of additives.

In Exceptional Cases Only When Doping is Required via an Open Tank Lid

• All cargo operations should be halted.
• Non-essential personnel should not be allowed on deck.
• Personnel undertaking the operation should stand upwind of the tank opening to minimize gas exposure.
• PPE is required to be fully implemented including use of a personal gas monitor and (where necessary) use of:
• SCBA.
• EEBD.
• Chemical resistant suits, face masks, etc.
• Doping should only be undertaken one tank at a time.

The doping plan should be discussed by all personnel involved on the ship and in the terminal. As a minimum, the plan should include the method of doping, PPE to be used, and the contingency measures. The SDS for any additives should be reviewed as part of the risk assessment process regarding hazard identification and risk mitigation measures. A copy of the SDS should be kept in the vicinity of the doping operation.

If additives are to be stowed on board, they should be well secured. See section 13.5 for further guidance.

8. TRAINING OF JUNIOR DECK OFFICERS

Train junior deck officers in the following:

• Loading & discharging operations.
• Responsibilities as per job description.
• Effective watch keeping.
• Safety matters.
• Company procedures & standard industry guidelines.
• Understanding of standing instructions.

Involvement at cargo operation planning stage is required for junior officers.

9. EXCHANGE OF INFORMATION

• Perform pre-arrival information exchange with port & terminal.
• Liaise with agents for port & terminal information.
• For safe handling of cargo ensure the following:
• Comply with smoking policy.
• No hot work during cargo operation.
• Avoid direct contact with cargo vapours.
• Drain cargo lines.
• Display cargo system line diagram in cargo control room & pump room.
• Mark capacity of drip trays under manifolds.
• Empty drip trays after completion of operation.
• Secure all valves after operation.

10. REFERENCED FORMS AND CHECKLISTS

HSSEQ-05 - Training Record