Section 2 Hull Structures

201. General

Hull structuress are to be in accordance with the relevant requirements in Ch 3, Sec 2 in addition to this section.

202. Access opening

1. Access to the machinery spaces of category A of ships is to be arranged within the forecastle.

2. Any access to such machinery spaces from exposed cargo decks is to be provided with two weath- ertight closures.

203. Cargo deck

1. Safe havens and escape routes for personnel from the cargo deck are to be properly marked and kept clear at all times. The vessel is to be equipped with a sufficient quantity and types of lashing and securing materials for the safe operation of the vessel.

2. In cases where cargo rails are fitted onto cargo decks, the structures under the stanchions of cargo rails are to be appropriately reinforced.

3.

4.

204.

1.

In cases where heavy cargo is carried on deck, effective means such as steel cradles, steel or wooden dunnages, etc. are to be provided so that weight is uniformly distributed onto deck structures.

Pad eyes for cargo securing and/or moving are to be welded directly to the deck plating; no dou- blers are allowed. The pad eyes are to be adequately supported by approved deck reinforcement. Dismountable pad eyes and stanchions are to have firm attachments to the deck sockets or holdings. All pad eyes are to be permanently marked with bead welded SWL values.

Cargo tanks

Liquid cargo tanks are to be according to the following :

(1) In cases where hazardous and noxious liquid cargo are loaded in tanks, the quantities of liquid cargo are to be limited to 800 m3 or a volume in cubic meters equal to 40% of ship dead- weight calculated at a cargo density of 1.0 t/m3. However, there are no such quantity limitations for drilling fluids (liquid mud, etc.), cargo fuel and non-noxious liquid substances.

(2) In cases where not bounded by bottom shell plating, fuel oil tanks, cargo pump-rooms or pump- rooms, cargointegral tanks are to be separated from other spaces by cofferdams having ac- cessible widths of 600 mm.

(3) Independent tanks are to be segregated from machinery spaces, propeller shaft tunnels, if fitted, dry cargo spaces, accommodation and service spaces and from drinking water and stores for hu- man consumption by cofferdams, void spaces, cargo pump-rooms, oil fuel tanks or other similar spaces.

14 Guidance for Offshore Support Vessels 2015

Ch 4 Offshore Supply Vessels Ch 4

2. Dry cargo tanks are to be according to the following :

(1) In cases where cargo tanks for dry cement or mud(barite, bentonite, etc.) are fitted, these cargo tanks are to be separated from engine rooms, accommodation spaces and service spaces by wa- tertight bulkheads and decks.

(2) Cargo transfer piping systems are, in principle, not to be led through machinery spaces.

However, in cases where such design is impractical, piping systems may pass through machinery spaces, provided that all pipe connections located within the machinery spaces are welded and

any detachable connections are arranged outside of such spaces.

3. Multi-functional cargo tanks

Where cargo tanks are intended to carry dry or liquid cargoes, the following are to be applied:

(1) With liquid cargo, the applicable requirements in 1. are to be complied with.

(2) With dry cargo, the applicable requirements in 2. are to be complied with.

4. Cargo tanks are to be located at least 760 mm measured inboard from the side of the vessel per- pendicular to the centreline at the level of the summer load waterline.

205. Spill coaming

Deck areas for handling oils and oil-based liquids are to be provided with a coaming around all pumps, transfer flanges, connections and other equipment where leakage may occur. Each coaming is to be adequately sized to contain deck spills and prevent spilled cargoes from entering accom- modation, machinery, control and service spaces or passing overboard. The coaming is to have a

height of at least 150 mm. Where drains are provided for the coaming, closing devices drains are to be permanently attached.

for these