Section 2 Piping systems for bilge, ballast, fuel oil, etc.

2.1.1 The pumping arrangements in the machinery space and at the forward end of the ship are to comply with the requirements for general cargo ships, in so far as they are applicable, and with the special requirements detailed in this Section.

2.1.2 Bilge, ballast and fuel oil lines, etc. which are connected to pumps, tanks or compartments at the ends of the ship outside hazardous zones and spaces, are not to pass through cargo tanks or have any connections to cargo tanks or cargo piping. No objection will be made to these lines being led through ballast tanks or void spaces within the range of the cargo tanks.

2.1.3 The fuel oil bunkering system is to be entirely separate from the cargo handling system.

2.1.4 Where non-permanent connections are required in piping systems between non-hazardous and hazardous spaces, two means of isolation are to be provided. One of these means is to provide positive separation by means of a removable spool piece or flexible hose, and blank flanges are to be fitted. The other is to be a non-return valve, or similar, in accordance with an acceptable National or International Standard that is appropriate for the design conditions of the piping system. The non-return valve and removable piece are to be located within the existing hazardous spaces. A notice is also to be provided located in a prominent position adjacent to the means of isolation, clearly indicating that the spool piece or flexible hose is to be removed, and blanking flanges are to be fitted, when the piping is not in use. The removable spool piece is to be clearly identified (labelled/painted in a distinctive colour) and stowed close to its working position.

2.2.1 Provision is to be made for the bilge drainage of the cargo pump-rooms by pump or bilge ejector suctions. The cargo pumps or cargo stripping pumps may be used for this purpose, provided that the bilge suctions are fitted with screw-down non-return valves and, in addition, an isolating valve or cock is fitted on the pump connection to the bilge chest. The pump-room bilges of small tankers may be drained by means of a hand pump having a 50 mm bore suction. Pump-room suctions are not to enter machinery spaces.

2.3.1 Cofferdams, which are required to be provided at the fore and aft ends of the cargo spaces in accordance with Pt 4, Ch 9, 1.2 Application and ship arrangement are to be provided with suitable drainage arrangements. Examples of acceptable arrangements are detailed in Pt 5, Ch 15, 2.3 Deep cofferdam drainage 2.3.2 and Pt 5, Ch 15, 2.3 Deep cofferdam drainage 2.3.3.

2.3.2 Where deep cofferdams can be filled with water ballast, a ballast pump in the main engine room may be used for emptying the after cofferdam. Where fitted, a ballast pump in a forward pump-room may be used for emptying the forward cofferdam. In each case, the suctions are to be led direct to the pump and not to a pipe system.

2.3.3 Where intended to be dry compartments, after cofferdams adjacent to the pump-room may be drained by a cargo pump, provided that isolating arrangements are fitted in the bilge system as required by Pt 5, Ch 15, 2.2 Cargo pump-room drainage 2.2.1; forward cofferdams may be drained by a bilge and ballast pump in a forward pump-room. Alternatively, cofferdams may be drained by bilge ejectors or, in the case of small ships, by hand pumps.

2.3.4 Cofferdams are not to have any direct connections to the cargo tanks or cargo lines.

2.4.1 Ballast tanks and void spaces within the range of the cargo tanks are not to be connected to cargo pumps, or have any connections to the cargo system. A separate ballast/bilge pump is to be provided for dealing with the contents of these spaces. This pump is to be located in the cargo pump-room or other suitable space within the range of the cargo tanks.

2.4.2 Ballast pumps shall be provided with suitable arrangements to ensure efficient suction from ballast tanks.

2.4.3 Where submerged water ballast pumps are fitted, they are to be located in separate compartments on opposite sides of the ship such that, in the event of hull damage due to grounding or collision, the risk of total loss of ballast pumping capability is minimised.

2.4.4 Ballast piping is normally not to pass through cargo tanks and is not to be connected to cargo oil piping. Provision may, however, be made for emergency discharge of water ballast by means of a portable spool connection to a cargo oil pump and where this is arranged, a non-return valve is to be fitted in the ballast suction to the cargo oil pump.

2.4.5 The portable spool piece should be mounted in a conspicuous position in the pump-room and a permanent notice restricting its use should be prominently displayed adjacent to it.

2.4.6 Shut-off valves shall be provided to shut off the cargo and ballast lines before the spool piece is removed.

2.4.7 The ballast pump is to be located in the cargo pump-room, or a similar space within the cargo area not containing any source of ignition.

2.4.8 Consideration will be given to connecting double bottom and/or wing tanks, which are in the range of the cargo tanks, to pumps in the machinery space where the tanks are completely separated from the cargo tanks by cofferdams, heating ducts or containment spaces, etc.

2.5.1 Deep cofferdams at the fore and aft ends of the cargo spaces and other tanks or cofferdams within the range of the cargo tanks, which are not intended for cargo, are to be provided with air and sounding pipes led to the open deck. The air pipes are to be fitted with gauze diaphragms at their outlets.

2.5.2 The air and sounding pipes required by Pt 5, Ch 15, 2.5 Air and sounding pipes 2.5.1 are not to pass through cargo tanks.

2.5.3 On oil tankers of less than 5000 tonnes deadweight, where wing ballast tanks or spaces are not required, the sounding and air pipes to double bottom spaces below cargo tanks may pass through the cargo tanks. However, the pipes are to be of heavy gauge steel, and they are to be in continuous lengths or with welded joints.

2.6.1 Ballast piping is permitted to be located within the cargo pump-room double bottom provided any damage to that piping does not render the ship's ballast and cargo pumps, located in the cargo pump-room, ineffective.

2.7.1 The fore peak tank can be ballasted with the system serving other ballast tanks within the cargo area, provided that:

1. the fore peak tank is considered as a hazardous area;

2. the vent pipe openings are located on open deck at an appropriate distance from sources of ignition. In this respect, the hazardous zones distances are to be defined in accordance with Pt 6, Ch 2, 14.2 Hazardous areas;

3. means are provided, on the open deck, to allow measurement of flammable gas concentrations within the fore peak tank by a suitable portable instrument;

4. the sounding arrangement to the fore peak tank is direct from open deck; and

5. the access to the fore peak tank is direct from open deck; alternatively, indirect access from the open deck to the fore peak tank through an enclosed space may be accepted, provided that:

   1. in case the enclosed space is separated from the cargo tanks by cofferdams, the access is through a gas-tight bolted manhole located in the enclosed space and a warning sign is to be provided at the manhole, stating that the fore peak tank may only be opened after it has been proven to be gas free, or any electrical equipment which is not certified safe in the enclosed space is isolated.

   2. where the enclosed space has a common boundary with the cargo tanks and is therefore a hazardous area, the enclosed space is to be well ventilated.