GL Section 31 Oil Recovery Vessels

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Section 31

Oil Recovery Vessels

A. General

1. Vessels specially designed, built, and equippedfor occasional handling, storage, and transportation of oil with a flashpoint below 60 C, recovered from anoil spill in emergency situations, in compliance withthe requirements of this section, may be given theClass Notation OR (Oil recovery and transportation).Vessels built for class notation OR are also to complywith requirements of Section 1 to 23 and 25 for Class

Notation OFFSHORE SERVICE VESSEL .

2. In addition to the requirements listed in 1, therequirements given in the GL Rules for Machineryand Systems (I-6-2), Section 10 and the GL Rules for Oil Recovery Vessels (I-1-9) have to be applied asappropriate.

3. The following main features of oil recoveryvessels dictate their structural configuration:

safety against fire and explosion during han-dling, storage, and transportation of oil recov-

ered from a spill,

supporting structures for equipment appliedduring oil recovery operations,

stability and floatability,

available power for supply to equipment usedduring oil recovery operations.

B. Documentation

In addition to plans and particulars required by Sec-tion 1, F. , additional plans and particulars as definedin the GL Rules for Oil Recovery Vessels (I-1-9),Section 1, D. shall be submitted for approval.

C. Basic Requirements

1. General

1.1 The ship shall be provided with a suitableworking deck for use in oil recovery operations. Theship shall be provided with storage tanks for recoveredoil and pumping and piping arrangements for transfer and discharge of recovered oil.

1.2 The ship shall have adequate stability andfloatability in all relevant operating conditions. Stabil-

ity and floatability properties will be considered for each particular case.

1.3 Visibility from the maneuvering station shall be such that the master can easily monitor oil recoveryoperations that occur on deck and in the water.

1.4 The oil tanks and the deck area where theoperation is performed shall be as far away from theaccommodation as possible.

2. Fire protection

2.1 For ships with cargo tanks forward of thesuperstructure, exterior boundaries of superstructuresand deckhouses enclosing accommodations, includingoverhanging decks that support such accommodations,shall be insulated to A-60 standard for the entire por-tions facing the hazardous areas and for 3 m aft or forward of these areas, whichever is relevant. Withinsuch boundaries, this requirement is also applicable toaccess doors. Alternatively, insulation to A-0 standardwith a permanently installed water spraying system incompliance with 2.4 may be accepted. Aluminum

bulkheads are not acceptable within these boundaries.

2.2 Requirement 2.1 is also applicable to shipswith cargo tanks aft of the superstructure, providedexterior boundaries of superstructures and deckhousesenclosing accommodations and overhanging decksthat support such accommodations are situated within10 m of the nearest hazardous area.

2.3 Portholes and windows in the area specifiedin 2.1 and 2.2 shall have the same fire rating as the

bulkhead in which they are fitted. This requirementdoes not apply to wheelhouse windows. Portholes and

windows that have a lower fire rating than required or that are protected by a water spray system in accor-dance with 2.4 shall be fitted with permanently in-stalled inside deadlights of steel having a thicknessequal to the steel bulkhead in which they are fitted.

2.4 Windows in areas specified in 2.1 shall haveA-60 integrity or be protected by deadlights during oilrecovery operations. Navigation bridge windows inareas specified in 2.1 shall have A-0 fire integrity.

2.5 To protect the working deck area, two semi-operable 25 kg dry powder fire extinguishers shall be

provided, stored in readily available spaces adjacent tothe working deck. In addition, the ship shall carry two

portable foam applicator units with at least four port-able 20 liter containers with foam concentrate, usingwater supplied by the ship's fire main.

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3. Arrangement of tanks

3.1 In general, tanks within the accommodationand/or engine room area are not to be used to storerecovered oil.

3.2 For the arrangement and segregation of tanksthe requirements of the GL Rules for Hull Structures(I-1-1), Section 24 and the Rules for Oil RecoveryVessels (I-1-9), Section 2 have to be applied.

3.3 All openings to the tanks, such as sounding pipes and hatches for placing portable pumps and hoses to recover the oil, shall be located on the open deck.

3.4 Tanks for recovered oil shall have suitableaccess from the open deck for cleaning and gas free-ing. Long tanks shall be accessible from both ends.

3.5 Normally, tanks exceeding a breadth of 0,58 B or a length of 0,1 L (B = rule breadth, L = rulelength), whichever is the greater, are to be providedwith wash bulkheads or similar arrangement to reduceliquid sloshing when partially filled. The height of tanks for recovered oil shall be at least 1,5 m. Internalobstructions in tanks for recovered oil shall be pro-vided with adequate openings to allow full flow of oil.For this purpose, the area of one single opening is to

be at least twice as large as the sectional area of thedischarge pipe. The openings shall be arranged toenable the tanks to be effectively drained.

3.6 Coatings in tanks for recovered oil shall be of an oil and dispersant resisting type.

4. Structural support of heavy components

4.1 Strength of supporting structures for equip-ment used during oil recovery operations can be basedon oil recovery operations taking place in moderatesea conditions.

4.2 Dynamic loads on cranes intended for useduring oil recovery operations, brought about by theship's motions, shall be taken into account. In gen-eral, scantlings of cranes and their supporting structure shall be based on at least twice the crane's working load.

D. Hazardous Areas

1. Hazardous zones

The hazardous and non-hazardous zones are defined inGL Rules for Machinery and Systems (I-6-2), Section10, A.2.

2. Access openings

2.1 The requirements of the GL Rules for OilRecovery Vessels (I-1-9), Section 2, B. apply.

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