Code of practice for vessels engaged in oil recovery operations
These guidelines are for the design, construction, ship's equipment and operation of offshore support vessels, which may be required to have the capability of handling, storing and transporting oil recovered from a spill in emergency situations.
Whilst constructing or adapting such vessels for the carriage of oil in bulk makes them tankers within the meaning of the various Merchant Shipping Regulations, it is recognised that there is a requirement for offshore vessels to recover oil within UK waters and that these vessels may not be able to meet all the tanker requirements.
The purpose of these guidelines is to draw attention to the minimum requirements which will have to be met, in order to satisfy the Marine Safety Agency (MSA) that such vessels are suitable to undertake OIL RECOVERY OPERATIONS.
These guidelines apply to vessels operating in UK waters, which, regardless of size, are constructed or adapted to handle, store and transport oil recovered from a spill of oil in emergency situations, e.g. for the recovery of oil floating on the water or generally combating oil pollution.
For special duties, e.g., lightening damaged oil tankers with cargo spillage and for ships of specialised types, other measures beyond the scope of this code may be necessary.
When an assessment of the arrangements - including an inspection of the vessel - has been completed to the satisfaction of the MSA and a satisfactory standard of safety has been achieved, the MSA will issue an Oil Recovery Certificate. This will provide a General Exemption from the regulations appertaining to tankers to enable the vessel to operate as a dedicated oil recovery vessel within UK waters. The Certificate will remain valid for a period not exceeding two years unless previously cancelled.
The following matters are covered by the guidelines.
The following information should be provided in order to ascertain compliance with the Code:
1) General Arrangement Plan showing the arrangement of equipment for oil recovery operations.
2) Structural Fire Plan showing details of entrances and openings in use in normal operation.
3) Details, drawings and certificates of Fire Appliances.
4) Drawing and specification of Gas Detection System showing details of where gas detectors are located.
5) Details of arrangement and capacity of all cargo tanks and substances to be carried.
6) Diagrammatic plan of oil transfer system and blanking arrangements.
7) Drawing of cargo tanks and materials used.
8) Plans showing delineation between Hazardous and Non-Hazardous areas.
9) Specification, details and Certification of portable gas testing equipment which are used to test atmosphere in conjunction with safe tank entry procedures.
10) Operations and Procedures Manual.
11) Plan and details of electrical arrangements used in supplying oil recovery equipment and layout of electrical equipment in Hazardous Areas.
12) Details of Portable Equipment carried for use in oil recovery operations.
In assessing the vessel for compliance with the provisions of the code the arrangements provided on board should enable the vessel to:
1) Handle, store and transport oil liable to be recovered from an oil spill.
2) Prevent ingestion of oils and flammable substances into machinery piping systems and safe spaces.
3) Ensure separation between hazardous and non‑hazardous areas.
B. Arrangements to be Provided
The vessel should be provided with the following arrangements:
1) A suitable working deck for use in oil recovery operations.
2) Designated storage tanks for recovered oil.
3) Independent pumping and piping arrangements for transfer and discharge of recovered oil.
4) Adequate stability in all relevant operational conditions. The arrangements are to be included in an approved stability booklet which should be provided on board.
5) Clear visibility from the bridge to allow the Master to easily monitor oil recovery operations both on deck and in the water.
6) Oil tanks and deck areas where oil recovery operations are undertaken are to be as far away from the accommodation as possible and not in any case to be within a distance of 3m.
B Hazardous and Safe Areas
Hazardous areas are defined as those areas in which combustible or explosive gases or vapours are liable to accumulate in dangerous concentrations.
Hazardous areas include:
1) Tanks for storage of recovered oil.
2) Cargo pump rooms.
3) Cofferdams and spaces adjacent to tanks intended for the storage of recovered oil.
4) Open spaces on deck where recovered oil may spill.
5) Spaces on open deck including semi‑enclosed spaces within a spherical radius of 3m of tank openings and openings to pump rooms or cofferdams (e.g., cargo tank hatches, inspection holes, ventilation openings and access hatches).
6) Spaces on open deck in the recovered oil tank area, including 3m forward and aft of the area and in areas where piping or other equipment for recovered oil is located, up to a height of 2.4m above uppermost deck. On ships with a non‑hazardous uppermost continuous deck, the hazardous area extends up to 2.4m above this area.
7) Enclosed spaces or semi‑enclosed spaces containing pipelines belonging to the cargo system.
8) Spaces which do not have overpressure ventilation which can be entered directly from a hazardous area or which have openings to a hazardous area.
9) Any area external to the vessel which is contaminated with oil, e.g., oil on the surface of the water.
C Tank Arrangements
Tanks should be such that there is separation between hazardous and non-hazardous areas.
1) Tanks within the accommodation and/or machinery spaces of the vessel should not be used for the storage of recovered oil.
2) Tanks intended for the storage of recovered oil should be separated from the machinery spaces and accommodation by means of cofferdams, tanks used for other purposes (fuel, ballast) or dry compartments other than accommodation.
3) All opening to tanks (sounding pipes, vent pipes, hatches for placing of portable pumps and hoses) for recovered oil should be located on the open deck.
4) Tank arrangements with removable manhole covers should be avoided where possible. Notwithstanding this, manhole covers may be provided for access from deck and/or void spaces to ballast or fresh water tanks.
5) Tanks should be arranged so that they can be easily gas freed.
6) Tanks used for storing recovered oil are to have suitable access from the open deck for cleaning and gas freeing.
7) Heating coils fitted in oil recovered tanks and adjacent tanks should be blanked off. Heating coils may be used to facilitate discharge of the recovered oil, in which case the steam returns should be led to an observation tank outside the machinery space.
D. Tank Venting
1) Venting arrangements should be in accordance with the normal requirements of the vessel.
2) Ventilation outlets from the oil recovered tanks should be led to the open deck.
3) The tank vent outlets should have a minimum height of 2.4m above deck and be located at a minimum horizontal distance of 5m away from openings, to accommodation, other gas safe spaces, ventilation intakes for accommodation, engine rooms and noncertified electrical equipment. Temporary pipe sections may be fitted to achieve this. All vents from oil recovered oil tanks should have flame screens fitted.
E. Arrangement of Piping Systems
1) The piping arrangements should be suitable for the filling, discharge and transfer of recovered oil and should be located outside the engine room and accommodation.
2) Where permanently installed oil recovery piping is arranged, it should be a dedicated system. If it is common to other cargo systems, suitable double blanking arrangements should be provided:
3) Blanking devices should be fitted as near as practicable to the tank.
4) Filling lines should be provided with means for injecting emulsion breaking chemicals. The arrangement should be such as to facilitate efficient mixing with recovered oil (e.g., on the suction side of the pump).
F. Miscellaneous Requirements
Diesel engines or other equipment which constitutes a possible source of ignition are not to be situated within oil tanks, pump rooms, cofferdams or other spaces liable to contain explosive vapours or in spaces immediately adjacent to oil tanks.
The exhaust lines of diesel engines, boilers and equipment containing sources of ignition and the vents of diesel engine crank cases should be led to a position outside the hazardous area. In addition suitable spark arrestors should be fitted.
B. Diesel Engines Used for Driving Oil Recovery Equipment
1) Where a diesel engine is utilised for the oil recovery process, it is should be positioned in a non‑hazardous zone and at least 3 metres clear of openings through which flammable vapours may be emitted.
2) Diesel engines should comply with the requirements of `Oil Companies Materials Association Publication' No. MEC‑1, as detailed below.
3) The Diesel engine should be fitted with a device for stopping it automatically in the event of:
a) high exhaust temperature;
b) low lubricating oil pressure;
c) over speed.
The automatic stop device should operate by closing a flap valve fitted in the engine air intake as close to the engine as possible.
4) The engine cooling fan should be of the non‑sparking type and the fan belt should be of the anti‑static type.
5) Diesel starting arrangements should be pneumatic, hydraulic, spring recoil, inertia or manual where possible. If electrical starting arrangements are used these should be certified 'flameproof'.
6) Spark arrestors and flametraps should be fitted to the exhaust system.
7) The surface temperature of the engine and exhaust system should not exceed 200°C when tested under full load conditions. Exhaust manifolds are to be suitably lagged. An approved flametrap should be provided on the air intake downstream of the cooler.
A. Fire Protection Arrangements
1) The structural fire protection arrangements within the accommodation spaces should be to the standard appropriate to the vessel when engaged upon its normal duties other than oil recovery.
2) In addition, to ensure adequate protection of the accommodation spaces from hazardous zones, the following fire protection arrangements should be complied with:
a) exterior boundaries of superstructures and deckhouses enclosing accommodation and including any overhanging decks which support such accommodation should be insulated to "A60" standard for the whole of the portions which face the gas dangerous zone and for 3m aft or forward of these whichever is relevant; or,
b) in lieu of the insulation, the said exterior boundaries may be protected by a permanently installed water spraying system. The system is to provide a capacity of 10 litres/min/m2, being fully activated by opening one valve on the bridge; and,
c) portholes and windows in the external boundaries mentioned in a) should be fitted with permanently installed inside deadlights of steel, having a thickness equivalent to the steel bulkhead. Aluminium frames should not be used.
3) The vessel's fire fighting appliances should be in accordance with the requirements appropriate to the normal duties, other than when engaged in oil recovery.
4) In addition a foam installation which may use portable foam applicators should be provided. The rate of supply of foam solution should be 0.6 litres/min/m2 of working deck area with a minimum throw of 15m. The foam installation should be capable of applying foam to any working deck area or cargo tank. The foam expansion ratio should not exceed 12:1.
5) For the protection of the working deck area, two 50kg dry powder fire extinguishers should be provided. The fire extinguishers should be placed near the deck area where the equipment for handling recovered oil is located and are to be fitted with hoses of adequate length.
6) At least two additional sets of breathing apparatus and protective clothing should be provided for personnel carrying out oil recovery operations.
7) The piping ventilation and pump room arrangements and precautions against oil spillage on deck should be appropriate for the carriage of flammable liquids and in general accord with current tanker practice.
A. Ventilation Systems
1) The ventilation systems for hazardous and non‑hazardous spaces should be independent. Safe spaces adjacent to gas dangerous areas should have mechanical ventilation with overpressure relative to gas dangerous areas. The overpressure in these areas should be approximately 0.5‑1 mbar and should be monitored. The inlet air should be taken from a safe area on open deck located as far as practicable from possible gas sources. The outlet air should be led to a safe area on the open deck.
2) Hazardous spaces should have mechanical ventilation extraction giving at least 6 changes per hour. The inlet air should be taken from a safe area on the deck.
3) Spaces which must be accessible at all times such as steering gear compartments should have a mechanical ventilation system of the extraction type capable of 6 changes per hour.
4) Other spaces which are not normally used during oil recovery operations should not be ventilated from hazardous zones even if the equipment within those spaces is certified for use in hazardous areas.
B. Entrances and Openings
1) Entrances, ventilation openings (inlets and outlets) and other openings to non‑hazardous zones, such as accommodation, service and machinery spaces, control stations and the wheelhouse which are in normal use and not provided with gas tight closures during oil recovery operations, should be located outside hazardous areas.
2) Access doors may, however, be accepted between such spaces providing:-
a) the non‑hazardous space has positive ventilation in relation to the gas dangerous zone;
b) the doors are self-closing and arranged to swing into the non hazardous space so that they are kept closed by the overpressure;
c) sign boards should be fitted, warning that the doors are to be kept closed during oil recovery operations.
3) Entrances, where possible, should be located at least 6m above the deepest load waterline. Additional safety precautions in lieu of these heights may be accepted.
C. Gas Detection and Alarm Systems
1) For the purposes of explosion protection, ships should be equipped with permanently installed gas detection systems which activate an audible and visual alarm when a concentration equal to 30% of Lower Explosion Limit (LEL) is exceeded.
NB: If no other data is available, propane may be used as the reference gas.
Detection points should be sited as follows:
a) at all ventilation inlets;
b) on the main deck, to give warning to those personnel working on the deck;
c) at entrances to accommodation, wheelhouse etc.;
d) in spaces, the boundaries of which enclose oil recovery tanks, e.g., void spaces, spaces between engine room and oil recovery tank.
Further detection points may be required, depending upon the structural features of the vessel and its conditions of service.
3) Portable gas measuring instruments of an approved type should be provided on board to facilitate safe tank entry. e.g., Oxygen Content Meter and Explosimeter.
Refer to Code of Safe Working Practices for Merchant Seamen, Chapter 17.
Electrical installations should be such as to minimise the risks of fire and explosion from flammable liquids.
B. Electrical Equipment in Hazardous Zones
1) Any electrical equipment within a hazardous zone should be in accordance with The Institute of Electrical Engineers (IEE) Regulations for the Electrical and Electronic Equipment of Ships with Recommended Practice for their Implementation, 6th Edition, 1990, as amended.
C. Electrical Equipment which is not Certified
2) Non‑certified safe electrical equipment located in hazardous zones and on open deck should be disconnected during oil recovery operations: Permanently fixed signboards should be fitted at the respective switches to warn against inadvertent reconnection during oil recovery operations.
D. Electrical Installations for Oil Recovery Equipment
1) The arrangement of power supplies to portable oil skimming and pumping equipment should as far as practicable be permanently installed and should be supplied from a connection box protected with a door which is interlocked with a switch.
2) The supply from the main switchboard to the connection box should be permanently installed and provided with separate switchgear, short circuit and overcurrent protection in each insulated phase.
3) The connection boxes should be located at easily accessible places and in such a way that cables are not carried through doors or portlights leading from working areas to machinery or accommodation spaces.
4) Portable oil skimming and pumping equipment and independent power packages should be certified as safe for operation in hazardous areas.
An Operations and Procedures Manual governing oil recovery, should be available on board for all ship's staff and personnel involved in oil recovery operations. The manual should do the following:
a) provide guidance on how to prevent any vessel operating in an atmosphere which may endanger the vessel and its personnel;
b) state the conditions and operational procedures to be followed to permit the vessel to operate safely on oil recovery duties;
c) draw attention to the principle that no duties, other than oil recovery, should be carried out unless the vessel is in a gas free condition.
Employers are reminded of their duty under the Merchant Shipping (Health and Safety: General Duties) Regulations 1984 to provide employees with any necessary information, instructions, training or supervision in order that they may safely carry out their duties without risk to themselves or to others.
The Master should ensure that all crew and personnel have read and are familiar with the details given in the Procedures and Operations Manual.
For guidance the manual should include information with regard to:-
1) Arrangement and equipment
A list of appliances and equipment provided for oil recovery operations with instructions on their mobilisation, installation and operation to include:-
a) checking of all equipment onboard to ascertain that it is certified for use in hazardous areas;
b) mounting and fastening of non permanent equipment;
c) blanking‑off of pipes;
d) assembling of air pipes;
e) disconnection of electrical power supply;
f) closing of openings between safe and gas‑dangerous areas;
g) start of additional ventilation equipment;
h) change-over to low suction for cooling water pumps;
i) fitting of signboards regarding the use of open flame, non-certified electrical equipment etc.;
j) availability of fire fighting equipment.
a) characteristics of oil cargoes‑to include flammability limit, explosive limits, petroleum vapour travel flashpoint and autoignition temperature;
b) hazards and hazard control‑to include explosion and flammability hazards, health hazards, environmental and corrosion hazards;
c) anti-static measures, monitoring techniques and precautions with equipment and systems;
d) safety equipment and protection of personnel;
e) emergency procedures;
f) guidelines regarding safe distance from an oil spill source and procedures to be taken if gases are traced on open deck (e.g., the vessel is to be withdrawn immediately);
g) gas measurements during operation (on open deck and in spaces where gas might accumulate) to include procedures to be adopted if gas is detected (e.g., cease operations and withdrawal from the area);
h) actions to be taken, when presence of gas detected, pressurisation of safe areas is lost or the ventilation system fails;
i) precautions against overfilling of tanks;
j) discharging of oil;
k) cleaning and gas‑freeing of tanks and pipes;
l) a reference should be made to highlight that an approved stability booklet is provided and should be consulted.
4) Equipment Identification and Maintenance
a) equipment should be marked to show that it is safe for use in the intended zones;
b) all equipment should be maintained in good working order. Records should be kept on board and be available for inspection to verify that the equipment is being maintained in a safe condition for its intended use.
The staff and any persons on board the ship which is to be used in oil recovery operations should receive suitable training to enable them to undertake these operations in a safe manner.
Such training should include:
a) types and sources of oil pollution;
b) tracking and surveillance of oil;
c) characteristics of oil cargoes‑to include flammability limit, explosive limits, petroleum vapour, travel flashpoint and auto‑ignition temperature;
d) hazards of oil and hazard control‑to include explosion and flammability hazards, health hazards, environmental and corrosion hazards. Anti‑static measures, monitoring techniques and precautions with equipment and systems;
e) safety equipment and protection of personnel;
f) emergency procedures;
g) guidelines regarding safe distance from an oil spill source and procedures to be taken if gases are traced on open deck (e.g., the vessel is to be withdrawn immediately);
h) gas measurements during operation (on open deck and in spaces where gas might accumulate), including procedures to be adopted if gas is detected (e.g., cease operations and withdraw from the area);
i) action to be taken upon gas being detected and/or if ventilation system fails, thereby losing pressurisation of safe zones;
j) precautions against overfilling of tanks;
k) discharging of oil;
l) cleaning and gas‑freeing of tanks and pipes;
m) requirements for controlling repair and maintenance operations during oil recovery operations.
The vessel's life-saving appliances should be in accordance with the requirements appropriate to the normal duties of the vessel. If additional personnel are carried for oil recovery duties then additional life‑saving appliances should be provided to accommodate the additional personnel.
Pollution prevention equipment such as oil discharge monitoring and control systems required by The Merchant Shipping (Prevention of Oil Pollution) Regulations 1983 should be that appropriate to the vessel when engaged in its normal duties other than oil recovery.
ISBN 0 11 551811 8