CTM 9.4	Chemical Tanker Manual CTM Ship-Shore Liaison and Cargo Handling in General	Doc No.: CTM 9.4 Revision: 01 Date: 15 Oct 2024 Issued by: DPA Approved by: MD

1 APPLICATION

This document applies to all Chemical Tankers managed by Company.

2 PURPOSE

The purpose of this document is to provide guidelines and procedures for the safe and efficient handling of cargo.

3 KNOWLEDGE OF AND FAMILIARIZATION WITH CARGO SYSTEMS

• Master, all Officers and ratings who will be involved in the cargo operations, upon joining the vessel, shall familiarize themselves with:
  • Arrangement, layout and operations of the cargo systems,
  • Any special feature the vessel may have relating to the handling of cargo.
• Chief Officer shall ensure following are permanently marked for identification:
  • All cargo lines
  • Valves (manifold, pump stack and common line valves)
  • Vent lines
  • P/V valves
  • Vapour recovery lines
  • Cargo heating system lines and valves
  • Tank cleaning lines and valves
  • Cargo pumps
  • Cargo heaters
  • Tank domes
  • Butter worth pockets
  • Sighting ports

4 LIAISON BETWEEN SHIP AND SHORE FOR CARGO OPERATIONS

4.1 Exchange of information prior arrival

Master shall communicate with relevant parties involved:

• To acquire necessary information regarding cargo and its readiness, etc.
• To give necessary information to the parties for safe and efficient operation. The following communication shall normally take place:

Vessel with Agent

• ETA, draft, tugs, pilot and other port information
• Defects on Vessel which may affect port and cargo operation
• Sizes and number of cargo manifold connections

Vessel with Pilot (directly or through agent)

• ETA at pilot station, draft, and others which are required for safe manoeuvring of Vessel

Terminal (berth master / cargo surveyor) to Vessel

• Quantity, S.G., correction factor, temperature, special requirements for cargo.
• Tank venting requirements and details of any vapour return lines required.
• Tank environmental control requirements, e.g., drying and inert gas.
• Check list, Terminal regulation, emergency plan, etc.
• Detail of Terminal facilities (distance, elevations to shore tank, booster pump, etc.)
• Number, and size of shore connection and estimated loading rate
• Depth of water at berth
• Information on weather or surroundings
• Terminal or Port Regulations on pre-washing of cargo tanks alongside the berth
• Details of reception facilities to receive slops (if applicable.)
• Any other limitation of the Terminal.
• Surging from passing vessels at berth.

4.2 Advice to terminal from vessel before start loading / discharging

The responsible officer of Vessel shall inform Terminal of the following:

• Information on Vessel
• General arrangement of cargo on arrival
• Vessel's draft and trim on arrival
• Details of Vessel's manifold such as flange sizes of cargo / vapour manifolds
• Any problem which may affect cargo operation
• Any operation on Vessel which may affect or delay commencement of loading or discharging
• Estimate draft upon completion of operation
• Cargo and Ballast Details before Loading
• Acceptable cargo quantities from terminal nominations
• Details of last cargo carried (normally last 3 cargoes), method of tank cleaning (if any), and state of cargo tanks and cargo pipelines.
• Mandatory pre-wash requirements, cargo names and quantity of washings for discharge to reception facilities.
• Quantity, quality and disposition of slops of cargo, if any
• Whether alongside tank cleaning is required in addition to pre-wash
• Loading Plans of Vessel
• Loading arrangements and procedures
• Proposed method of venting from the cargo tanks
• Maximum pressure at the manifolds and expected loading rate
• Cargo Details before Discharging
• Kinds of cargoes and their characteristics
• Special precautions given by cargo owner for discharging
• Cargo quantities and loaded conditions
• Any change of the ullage since loading, due to unreasonable or unknown cause
• Cargo temperature on arrival
• If Vessel has part cargoes which will remain on board, cargo name, volume and tank distribution of each cargo.
• Discharging Procedures of Vessel
• Discharging arrangement and procedures
• Maximum discharging capacity and pressure of the cargo pumps, and intended discharging rate and pressure

4.3 Advice to vessel from loading / discharging terminal / surveyor

The responsible officer shall acquire the following from Terminal:

• Cargo Information
• Kinds of cargoes and their characteristics
• Special precautions for cargo handling
• Quantities of loading cargoes
• Foot samples / Normal samples taken, and any suspension of cargo operation while samples are being analysed.
• S.G., correction factor, MSDS etc.
• Loading temperature of cargoes
• When necessary, certificates and MSDS for inhibitors to be added to cargoes

Loading Plan

• Loading procedures
• For each cargoes, maximum loading rate
• Number and sizes of cargo hoses or loading arms available to use
• Limitation of movement of cargo hoses or loading arms
• Maximum working pressure of Vessel / Terminal connections
• Communication / Signaling procedure for control of loading including emergency stop procedure

Discharging Plan

• Cargo receiving procedures of Terminal
• For each cargo, maximum receiving rate
• Maximum pressure at Vessel / Terminal connections
• Any other Terminal limitations or regulations

4.4 Cargo operation plan

Cargo operation plan shall be agreed amongst:

• Vessel responsible officer
• Terminal representative
• Cargo surveyor

4.5 Communication during cargo operations

Ship’s responsible officer shall establish reliable communications system with terminal, agreed in writing.

• Testing of Communication system before loading or unloading commences.
• Establishing a secondary stand-by system and testing the same.
• Allowance for the time required for action in response to signals.

5. GENERAL REQUIREMENTS FOR CARGO OPERATIONS

5.1 Ship checks prior to arrival

Chief Officer shall supervise following checks/tests:

• Level gauges, level alarms, pressure sensors, thermometers and other in-tank instrumentation - are operational and accurate.
• High level and overfill control alarms – are functional
• Hatches, lids and openings that are not required to be open - are firmly closed.
• Cargo pipelines and cross-over valves and all drains – are closed and secured.
• Cargo and bunker pipelines not in use – are securely blanked and fully bolted. (At the manifold and at the pump stack for Deep Well pumps).
• All cargo tank openings such as tank domes, Butterworth pockets - are securely closed.

5.2 Ship checks after arrival prior to cargo operations

Chief Officer shall ensure following important checks are made prior to cargo transfer operations:

• Complete cargo information is available to the vessel.
• Cargo Tanks to be inspected by surveyor are well ventilated, safe for entry and marked so.

Coution:

• Comply with enclosed space entry procedures when entering tanks.
• Cargo Tanks are secured after the inspection.
• Sea suction and overboard discharge valves connected to ballast system are closed and lashed when not in use.
• All deck scuppers and any open drains onto jetty are effectively plugged
• Cargo manifolds are ready for connection to shore hoses.
• Cargo manifolds are labelled to identify product to be loaded through each line.
• Pump room ventilation system is put on well in advance.
• Cargo venting system is correctly set, appropriate for the operation.
• Intakes for central air conditioning system and mechanical ventilation system is checked for partial recirculation.
• Fire-fighting, Pollution prevention equipment is ready for immediate use.
• Correct personal protective clothing is immediately available and is being worn as necessary
• Ship and shore vapour systems are compatible and that the system will operate in compliance with local and terminal regulations.
• An inhibitor certificate is available for self-reacting cargoes, as applicable.

5.3 Closed loading

Master/Chief Officer shall ensure:

• Cargo is loaded with the ullage, sounding and sighting ports securely closed.

Coution:

• Caution: On vessels without inert gas systems, personnel operating gauging/sampling equipment must comply with the precautions highlighted in relevant sections of ISGOTT.
• Vapour displaced by the incoming cargo is vented to the atmosphere via the:
  • mast riser(s) or through
  • high velocity or
  • constant velocity valves
  either of which will ensure that the vapours are taken clear of the cargo deck.
• High level alarms are kept operational during the entire period of closed cargo operations.

Note:

• Anticipate the activation of these alarms and take immediate necessary action upon activation.
• Explicit instructions are left about action to be taken in case of inadvertent or unexpected activation of high level alarms.

5.4 Closed discharging

5.4.1 Inerted vessels

Vessels correctly operating their inert gas systems may conduct closed discharging operations without any additional or particular precautions.

5.4.2 Non-inerted vessels

Chief Officer shall ensure:

• Discharging takes place with all ullage, sounding and sighting ports closed.
• Air is admitted to the tanks by the dedicated venting system.

Note:

• Where the design of the vessel does not allow admittance of air via the vapour system at a satisfactory rate, air may be admitted via a sighting or ullage port providing it is fitted with a permanent flame screen.
• When cargo is being run between tanks during discharge operations, vapours are vented to deck as per procedures given in closed loading above.

5.5 Lining up of cargo and other valves

The Chief Officer shall:

• Personally, supervise the initial setting / lining up of all cargo lines/valves, vapour system valves, ballast system valves and heating system valves, including manifold jumper and flexible hose line-up.
• Before starting cargo operations, ensure that all cargo valves are closed and then open the necessary valves.
• Ensure checks are made to confirm that:
  • the flanges of removable parts such as reducers, cargo hoses and elbows are properly fitted and tightened
  • all open flanges are covered with blank flanges
• Drain plugs / valves on each cargo line, manifold and drip trays are shut.
• After lining up, another officer shall make a second independent check of the pipeline system for the proposed operation.

5.6 Safety of tools, machinery and materials

Chief Officer shall ensure tools, machinery and materials to be used in cargo areas comply with the following requirements:

• Tools, when used or dropped, do not give off sparks.
• Electric appliances are certified to be intrinsically safe or explosion-proof.
• Machinery is of such structure and material as will safeguard personnel against electrostatic generation and discharge.

5.7 Cargo hose connection

Information:

• As a general rule, and in accordance with the terms of Charter parties, terminal hoses will be used for the connection between ship and shore.
• Also it is the terminal’s responsibility to connect and disconnect shore hoses on the vessel’s manifold.
• However, there may be some exceptions where connection and disconnection must be done by the ship’s crew.

5.8 Clearing of cargo hoses

Chief Officer shall:

• When clearing the line after loading a static accumulator cargo, minimise the introduction of gas (which will bubble up through the cargo) into the tank.
• If nitrogen is used to clear the cargo hose after loading a cargo treated with an inhibitor that depends on oxygen, take care to minimise the volume of nitrogen entering the tank.

5.9 Disconnection of cargo hoses

Chief Officer shall:

• After the transfer of cargo is complete, ensure procedures are followed to minimise residues in the line.

Coution:

• All operations when the hose and loading arm are disconnected represent a deliberate breach of the cargo containment system.
• Chief Officer shall ensure that all possible precautions are taken to prevent incidents or accidents.
• Ensure personnel engaged in hose disconnection wear appropriate PPE suitable for the actual cargo.

6. SHIP-SHORE SAFETY CHECKS

6.1 Ship/shore safety checklist

• Following shall jointly complete the Ship/Shore safety checklist:
  • Responsible officer
  • Terminal representative
• They shall verify each item before ticking it off.
• OOW shall recheck Items “R” of checklist at agreed intervals.

Some of the important points from the Ship-Shore safety checklist are discussed in the following sections.

6.2 Access to the ship

Chief Officer/OOW shall ensure:

• The means of access is:
  • close to the living accommodation,
  • placed conveniently for supervision, and
  • preferably aft of the cargo manifold area.
• Gangway or other means of access is:
  • properly secured, and
  • provided with an effective safety net.
• Lifesaving equipment such as a lifebuoy is available near the access point.
• Access control as per the ISPS code requirements is maintained.
• During darkness, there is sufficient illumination for means of access and the surrounding areas.

6.3 Fire-fighting equipment

Chief Officer/OOW shall ensure:

• Fire plan along with crew list and stowage plan is placed at gangway.
• At least two fire hoses, one aft and one forward of manifold are run out and connected.
• Fire main is pressurized or if not practical, fire pump is in a standby condition.
• Fire/Foam Monitors are ready for use.
• Foam/Dry powder extinguisher (or equivalent) are placed near the Manifold.
• Location of international shore coupling is advised to terminal.

6.4 Pollution prevention

Chief Officer/OOW shall ensure:

• Save-alls under each manifold connection is kept dry.
• Any cargo spillages are drained at the earliest opportunity.
• Deck scuppers and any open drains onto jetty are effectively plugged.

Note:

• Accumulation of rainwater must be drained periodically and scupper plugs replaced immediately. Scupper plugs must not be left open unattended for drainage of rainwater. Contaminated water shall be transferred to a slop tank or a suitable receptacle.
• Cargo and bunker pipelines not in use are securely blanked and fully bolted. (At the manifold, and at the pump stack for deep well pumps).
• Cargo tank openings such as tank domes & Butterworth ports are securely closed.
• Spill collection/mitigation gear as required by the SOPEP/SMPEP is available for immediate use:
  • Relevant gear is deployed at manifolds and main deck aft.
  • Spill containment pumps (adequately grounded) are placed at aft main deck.

6.5 Ship’s readiness to move

Master/Chief Engineer shall ensure:

• Ship is ready for departure at short notice in the event of an emergency.

6.6 Smoking and naked lights

Chief Officer/OOW shall ensure:

• Company & Terminal smoking regulations are always complied with.
• Naked lights are prohibited on the tank deck and in any other place where flammable gas may be present.

6.7 Galley stoves and cooking appliances

Chief Officer/OOW shall ensure following are strictly complied with:

• Recommendations of International Safety Guide for Oil Tankers and Terminals (ISGOTT).
• Any restrictions imposed by the regulations of a port.

6.8 Portable electrical equipment

• The use of portable radios, tape recorders, Walkman, mobile phones, electronic calculators, pagers, cameras and other such equipment is prohibited:
  • in hazardous zones or
  • any other areas where flammable gas may be encountered (unless approved for use in a flammable atmosphere).
• Mobile phones carried by terminal staff or other visitors must be:
  • Either clearly identifiable and certified as being intrinsically safe
  • Or kept switched off in hazardous zones.
• Only torches approved by a competent authority for use in flammable atmosphere may be used.
• Changing of battery for any of the permitted equipment is not permitted in:
  • in hazardous zones or
  • any other areas where flammable gas may be encountered.

6.9 Helicopters

Master/Chief Officer shall not permit Helicopter operations over cargo tank deck unless:

• all other operations have been suspended and
• all cargo tank openings are closed.

6.10 Radar scanners

Information:

• The radiation of radar waves from a properly sited radar scanner presents no ignition hazard, but
• the operation of high-powered 10 cm radar may induce an electrical potential into nearby conductors at the berth.
• The operation of radars may involve running non-approved electrical equipment.

Chief officer shall:

• Consult the terminal before using or repairing such equipment.

6.11 Communication equipment

• Handheld UHF/VHF portable transceivers must be of an intrinsically safe type:
  • in hazardous zones or
  • any other areas where flammable gas may be encountered.
• Mobile telephones usage both in port and at sea shall be confined to:
  • private cabins,
  • designated smoking areas or
  • any other areas within the accommodation designated by the Master.

Coution:

• In general, mobile telephones should not be carried in or through hazardous areas. If this is necessary, the equipment must be switched off. Visitors must be instructed accordingly.
• VHF must be operated at low power (1 W) while alongside a tanker terminal.
• MF/HF main transmitting antennae shall be earthed or isolated whilst the ship is alongside the berth.
• AIS – Master shall ensure:
  • If port authorities request the AIS to be switched on, switch the unit to low power (1W).
  • Where this is not possible, the AIS is switched off and the port authorities informed accordingly.
  • If it is switched off whilst alongside, it is reactivated upon leaving the berth.

6.12 Ship/shore insulation and bonding cables

• The Chief Officer shall:
  • Ensure hose strings and metal arms are fitted with:
    • insulating flange or
    • a single length non-conducting hose
    to provide protection against static electrical discharge during cargo hose connection/disconnection.
  • Ensure the following are electrically continuous:
    • All cargo lines on the vessel after the insulating flange described above.
    • All lines on the terminal side to the jetty earthing system (to be confirmed by terminal representative).

Note:

• Switching off the cathodic protection system is not a substitute for the installation of an insulating flange or a length of non-conducting hose. Refer to ISGOTT and terminal regulations for cathodic protection system.
• Assess potential dangers of ship/shore bonding cable if such bonding cable is required by local regulations. Precautions shall include:
  • Visual inspection of the cable to ensure it is electrically and mechanically sound.
  • Connection point for the cable to be well clear of the manifold area.
• The cable shall be attached:
  • before the cargo hoses are connected and
  • removed only after the hoses have been disconnected.

6.13 Vessel and Terminal Emergency Procedures

• Vessel's responsible officer and Terminal representative shall agree on emergency response procedures to be followed by each party, especially for cargo spill or fire.
• The procedure shall include:
  • means of communication and
  • roles of each party.

7. SAFETY SYSTEMS INSTALLED ON BOARD

7.1 Venting arrangements

Information:

The venting arrangements of cargo tanks are so designed and operated as to ensure that neither pressure nor vacuum in cargo tanks shall exceed the design parameters and be such as to provide for:

• The flow of small volumes of vapour, air or inert gas mixtures caused by thermal variations in the cargo tank through Pressure/Vacuum valves.
• The passage of large volumes of vapour, air or inert gas mixtures during cargo loading, inerting or ballasting.

7.2 Preventive measures against liquid rising in the venting system:

Information:

The cargo tanks are fitted with High level and Overfill alarms independent of the level gauges.

7.3 Secondary means of pressure / vacuum relief (CDI 5.5.26)

Information:

Cargo tanks are fitted with a secondary means of allowing full flow relief of vapour, inert gas or air either in way of:

• Second P/V valve, or
• Pressure Sensors fitted to each tank with monitoring system in cargo control room and alarms for Over/Under Pressure of the tank or
• One or more Pressure/Vacuum breaking devices provided to prevent tank being subjected to Over/Under pressure.

In case of Pressure sensors/alarms fitted, Chief Officer/OOW shall:

• Check any alarm emanating in the CCR for its identity, location, and
• Investigate before it is reset.

7.4 Alarm settings of cargo tank pressure sensors

Cargo Tanks Inerted, Vapour return line Not Connected

• High pressure – PV Valves Relief Valve Setting + 10%
• Low-pressure - Above Zero (Recommendation 1Kpa)

Cargo Tanks Not Inerted, Vapour return line Not Connected

• High pressure – PV Valves Pressure Relief Valve Setting + 10%
• Low-pressure - PV Valves Vacuum Relief Valve Setting + 10%

Cargo Tanks Inerted, Vapour return line Connected

• High pressure – Not more than 90% of lowest pressure relief valve setting in cargo tank venting system.
• Low-pressure - 1 Kpa (100mm Water Gauge)

Cargo Tanks Not Inerted, Vapour return line Connected

• High pressure – Not more than 90% of lowest Pressure relief valve setting in cargo tank venting system.
• Low-pressure - lowest Vacuum relief valve setting in the cargo tank venting system.

8. PRESSURE SURGE

The Chief Officer must make all personnel involved in cargo operations aware of such hazards and the potential consequences such as structural rupture.

Precautions include the following:

• Approved shutdown procedures shall be in place.
• Pumps shall be stopped or pump discharge valves shut before manifold valves or valves in the shore pipeline are shut.
• During loading, when the flow is diverted from one tank to another, the valves on the tank about to receive cargo shall be fully open, before valves of the tank to be isolated are shut.
• On completion of loading, the flow shall be stopped by the terminal using shore valves and not by shutting off the ship’s manifold.

9. TANK OVER-PRESSURISATION AND UNDER-PRESSURISATION

9.1 Introduction

Over-pressurisation of cargo and ballast tanks is caused by compression of the ullage space due to the inadequate release of vapour or by the overfilling of the tank.

Under-pressurisation of cargo and ballast tanks is caused by not allowing inert gas, vapour or air into a tank whilst liquid is being discharged.

Consequences:

The consequences may be serious deformation of the tank structure and its peripheral bulkheads or catastrophic failure. This can seriously affect the structural integrity of the vessel and could lead to fire, explosion, and pollution.

9.2 Causes of tank over-pressurisation

Information:

Over-pressurization usually occurs during the following operations:

• Loading
• Internal Transfer of Cargo or ballast
• Inerting
• Purging
• Padding
• Drying
• Line clearing or Pigging

For definitions on the above, see CTM 9.1 Appendix 1 for Definitions.

This can be caused by one of the following:

• Overfilling of the tank with liquid.
• Inadvertent closing (or failure) of the tank’s vapour (or inert gas) isolating valve to the vapour line (or inert gas line).
• Failure or seizure of the venting valve.
• Choked flame arresters/screens.
• Loading the tank at a rate which exceeds the maximum venting capacity.
• Ice forming on vents during cold weather conditions.
• Ice on the surface of the ballast.
• Restriction in the vapour lines caused by wax, residues or scale.
• Inert Gas supply at high flow rate/pressure from shore for atmosphere control of cargo tanks compared to the venting arrangement.

9.3 Precautions to prevent over-pressurisation of tanks (CDI 5.5.26)

The Chief Officer shall:

• Establish a procedure/system to:
  • Control the setting of the high velocity vent valves on the vent lines.
  • Record the status of all valves in the system and prevent them from being incorrectly or casually operated.
  • Set the valves in the correct position for the operation.
  • Monitor that they remain correctly set.
• Restrict the operation of the valves to authorized personnel only.

Note:

• On vessels with inert gas systems where isolating valves are fitted to the branch line to each tank, SOLAS requires these valves be “provided with locking arrangements which shall be under the control of the responsible ship’s officer”.
• Ensure:
  • Valves are kept locked in desired position, and keys are kept in custody of responsible officer.
  • Regular maintenance (as per PMS) to avoid failure or seizure of isolating valves, pressure/vacuum valves or high velocity vents.
  • Pre-operational testing.
  • Adequate training and awareness of the operators.
• Have maximum filling rates for each individual tank available for reference. This is to protect against over-pressurization through filling tanks too quickly.
• Ensure tank vents are checked to confirm that they are clear when the operation commences.

9.4 Causes of tank under-pressurisation

Information:

These are similar to those of over-pressurization, particularly:

• Inadvertent closing (or failure) of an isolating valve on the vapour line or inert gas line.
• No replenishment of air or inert gas during discharge of cargo.
• The inert gas fan not being run due to breakdown or failure to operate it.
• Failure of one of the inert gas supplies valves.
• A choked flame screen on the vapour inlet line.
• Ice forming on the ballast vents during cold weather conditions.

9.5 Precautions against tank under-pressurisation

The precautions to guard against under-pressurization are the same as those relating to over-pressurization (See Section 9.3).

The methods of reducing a partial vacuum in a tank are either to:

• Raise the liquid level in the tank by running or pumping cargo or ballast into the affected tank from another tank or to
• Admit inert gas or air into the tank ullage space.

Chief officer/OOW shall take the following precautions:

• On ships with an Inert gas system: Admitting inert gas at a high velocity to return the tank to a positive pressure could cause an electrostatic hazard. Observe static electricity precautions.
• On ships without an inert gas system: Where it is not possible to reduce the partial vacuum other than by admitting air into the tank, take care to ensure that foreign objects with a possible ignition capability, such as rust scale, are not drawn into the tank.

10. INTERNAL TRANSFER OF CARGO

If it may be required to transfer cargo internally while on passage:

• To attain a desired trim,
• To change stowage or
• For the safety of the vessel and her crew,

The Master shall:

• Advise COMPANY Marine Department and seek concurrence.
• Advise Charterers / Cargo owners of his intention.
• Proceed only after written instructions are received from Charterers / Cargo owners.

On completion of the transfer, ensure:

• Ullages and temperatures of the concerned cargo tanks are taken.
• A new ullage sheet is drawn up and conveyed to all parties.
• Confirm the quantities/ullages of all other cargo tanks not involved in the internal transfer to ensure they are intact.

11. MEASURES TO PREVENT CONTAMINATION

11.1 Water contamination

The Chief Officer shall:

• Arrange for checking of items which may give rise to water leakage:
  • Oil tight hatches (OTH)
  • Tank cleaning openings
  • Cargo lines (Flanges and valves)
  • Ventilation lines and posts
  • Level gauges (Flange and hand hole flanges, etc.)
  • Hydraulic motor area of the submerged cargo pumps
  • Ullage holes
  • Sounding pipes of C.O.T.
  • Nitrogen purging lines
  • I.G.S. inlet lines, etc.
• Ensure preventive measures are taken for avoiding water contamination which include:
  • Check the packing condition periodically of the following:
    • Oil Tight Hatches
    • Tank Cleaning Openings
    • The cap of ullage holes and sounding pipes of C.O.T.
  • Carry out leak checks at regular periods for:
    • All valves, flanges, and pipes of the cargo lines
    • Vent lines and posts of C.O.T.
  • Seal and cover the OTH when carrying cargoes which are sensitive to chlorides and water:
    • Seal with silicon seal and without fail OTH, Tank cleaning openings, sounding and ullage holes, etc.
    • Cover with canvas solidly.
  • Cross-checking the sealed/covered condition and carrying out draining of all of vent-post frequently.

11.2 Contamination due to other cargoes

The Chief Officer shall consider the following points:

• Thorough segregation may be necessary when different parcels of cargo are carried in tanks served by common systems.

Note:

• When carrying toxic cargoes, it is a requirement that cargo piping and pumps, as well as tank venting systems, are separated from those containing other products,
• This is to prevent:
• - any leakage causing toxic contamination of non-toxic products and
• - subsequent exposure of personnel unaware of the contamination.
• On ships with common pipeline systems, separation required can be achieved by:
  • Inserting two blank flanges (spectacle plates) with a bleed drain in between, or
  • By removing a spool piece and using blank flanges strong enough to withstand the pressure expected.

11.3 Contamination due to mixing of cargo vapours

Whenever incompatible cargoes are carried:

• The Chief Officer shall ensure that the vapour return lines are kept segregated for these cargoes.

12. CARGO MEASUREMENT

12.1 Measurement procedures

The Chief Officer shall follow the below guidelines for cargo measurements:

1. Obtain and record Vessel's draught, trim and list.
2. Drain hoses or loading arms, and deck lines into tanks.
3. Check segregated ballast tanks are free of cargo.
4. Check all cofferdams and double bottoms.
5. Measure and record all liquids present.
6. Take Ullages of all cargo tanks. Read and record all measurements to the nearest millimetre.
7. Check and record reference ullage in each tank.

Note:

• Mark reference ullage on tank hatch in vicinity of where dips are normally taken
8. Determine and record the cargo temperature in each tank. Read the thermometer to the nearest point of degree.
9. Take temperature readings at top, middle, and bottom and calculate the average temperature for each tank.
10. Obtain the advised density of each product from the loading terminal. Ascertain whether quoted as a density in air or in vacuum.

Cargo Calculation:

The Chief Officer shall carefully calculate the quantity of each grade on-board using:

• Applicable tables, and the
• Relevant correction factors,
• Taking into account all elements of vessel's condition.

12.2 Safety precautions

The Chief Officer/OOW shall ensure the following precautions are taken when measuring cargo quantities:

• Minimise gas on deck.
• Prevent air from entering into tanks which are in an inerted condition.
• Implement relevant electrostatic precautions.
• Use approved equipment.
• Use appropriate PPE.

Please also refer to ISGOTT and ISG for Chemicals.

12.3 Cargo non-conformance (CDI 5.3.60)

In case of any discrepancies in quantity, quality, temperature, colour etc., inform:

• Marine Superintendent
• Charterers
• Owners

13. MAINTENANCE

13.1 Maintenance of Cargo Equipment

Responsible Officer for Maintenance – Equipment

• Chief Engineer: Cargo pumping system
• Chief Officer (with Chief Engineer assisting as required): Cargo valves, cargo gauging devices, instrumentation such as high/overfill alarms, pressure sensors, tank temperature sensors, tank washing machines and heater.

See CTM 9.4 Appendix 1 – Summary of Test Records and Intervals.

13.2 Leak Test of Submerged Cargo Pump (Purging Routine)

Information:

• Submerged cargo pumps are to be tested for leakage of their mechanical seals and cofferdam with compressed air of suitable pressure as per the maker's instruction (about 2.0kg/cm²).
• This test identifies the amount of hydraulic oil or cargo which leaked from the mechanical seals into the cofferdams.
• This test is commonly called "Purging of Pump Cofferdam."

The Chief Officer shall:

• Arrange for the test to be carried out on the following occasions unless specified otherwise by the pump manufacturer’s manual:
  • After completion of cargo tank cleaning
  • 1 or 2 days after loading
  • Before unloading
  • After unloading

Note:

• Record the results of tests in Purging Log Form and submit a copy to Marine Superintendent.
• After the leak test, keep the cofferdams pressurized with the tank test air, water, etc., as specified in the pump manufacturer’s manual.

13.3 Tests and Inspections of Cargo Pipelines and Hoses

Cargo Pipeline Testing:

• Cargo Pipeline and associated valves shall be hydrostatically pressure tested annually to at least 150% of the maximum allowable working pressure.
• All cargo pipeline reducers, U pieces, and Y pieces shall be annually pressure tested to 150% of maximum allowable working pressure.
• Vessel should have ship-specific procedures for carrying out pipeline pressure testing.

Cargo Hose Condition:

• The Chief Officer is responsible for the proper condition and functioning of cargo hoses and piping systems. He shall ensure that each non-metallic transfer hose must:
  • Have no unrepaired loose covers, kinks, bulges, soft spots, or any other defect which would permit the discharge of oil or hazardous material through the hose material.
  • Have no gouges, cuts, or slashes that penetrate the first layer of hose reinforcement.
  • Have no external deterioration and, to the extent internal inspection is possible with both ends of the hose open, no internal deterioration.

Note:

• All cargo hoses on board must be inspected prior to each use.
• When used, hoses must be:
  • Inspected regularly for leaks or damage by appearance.
  • Correctly connected with full bolts and supported.

  Coution:

  • Make sure that they are not crushed between vessel and shore / barge / vessel.
  • Of sufficient length to allow for the vessel's movement.
  • Prevented from putting excessive strain on the manifold, especially when it is extended by an unsupported reducer piece.
  • Handled in such a way as to avoid chafing damage (rubber pads may be used to prevent chafing).
• On completion of cargo operation, the hose should be:
  • Drained and cleaned.
  • Covered with blank flanges.

Cargo Hose Testing:

• The Chief Officer shall ensure that cargo hoses are tested annually to at least 1.5 times the maximum allowable working pressure.
• The vessel has a ship-specific procedure for carrying out hose/pipeline testing.

Cargo Hose Marking:

• Each cargo hose shall be marked with the following:
  • For Chemical cargoes, the words “Chem Service” and for Oil products “Oil service”.
  • Maximum allowable working pressure.
  • Maximum & Minimum service temperature.
  • Date of the annual test conducted and pressure tested to.

  Note:

  • Cargo hoses whose expiration date has been reached must be withdrawn from service but shall such date shall not exceed 10 years in service.
  • Each cargo hose type onboard shall have a retirement age defined in consultation with cargo hose manufacturer.
  • Each hose should be individually numbered for identification purposes.
• Ensure that a list of cargoes that can be handled by the hoses is available on board.

13.4 PV Valves

The Chief Officer shall ensure:

• P/V valves are routinely inspected, overhauled, and tested. For maintenance routine, refer to section C.
• Vent lines are washed after carriage of polymerizing and solidifying cargoes.

Coution:

• Pay Particular attention to valves sticking due to residues on the valve seats and also flame arrestors getting blocked.
• PV valves test kit is available.

14. REFERENCED FORMS AND CHECKLISTS

• CHEM 06A - Ship Shore Safety Checklist
• CHEM 03A - Cargo Calculation Ullage

15. APPENDICES

• CTM 9.4 A1 Summary of Test Records and Intervals