5 Additional installations of IBTS
In addition to the installations required by the Convention, the following installations should form part of the IBTS:
5.1 Drainage system
5.1.1 Drip trays or coamings with sufficient depth should be provided under the equipment used for oil such as diesel engines, burners, pumps, heaters, coolers, filters and tanks to contain spillage of oil.
5.1.2 Drip trays or coamings with sufficient depth should be provided under the equipment used for water such as pumps, heaters, coolers, filters, tanks, condensers and boilers to contain spillage of water.
5.1.3 Independent drainage arrangements for oil and water to sludge tanks and the bilge water holding tank should also be provided. Any open water drain in the engine-room falls under the definition of oily bilge water from engine-rooms. Such water shall be disposed ashore or via an oily water separator overboard.
5.1.4 Independent drainage of clean water drains from equipment not normally containing oil should be to clean water tanks.
5.2 Pre-treatment unit for oil separation
Pre-treatment may take place in dedicated equipment or bilge primary tanks. A bilge primary tank is a tank which separates oil from oily bilge water by gravity. It may make use of a cascade with drainage facilities for the oil on the top so as to enable primary separation of oily bilge water. Facilities to remove sediments should be provided.
Refer to the example of a bilge primary tank shown in Figure 1.
Figure 1 - Example of a bilge primary tank
5.3 Storage tanks
5.3.1 Clean drain tank: Tank for the retention of clean drains.
5.3.2 Oily bilge water holding tank: Tank for the retention of oily bilge water.
5.3.3 Oil residue (sludge) service tanks: Tank for preparation of oil residue (sludge) for incineration.
5.4 Discharge arrangement of clean drains
The overboard discharge arrangement of clean drains should be independent from the system for oily bilge water. Cleaning of equipment having clean drains should take account of the proper handling of chemical cleaning agents (e.g., emulsifiers) and wash water residue (including soot and sooty oil). The cleaning agent/wash water residue can foul an oil filtration system and should therefore be subjected to separate collection and/or filtration (e.g., portable units).
5.5 Exclusive pump for the oily water separator
It is preferable that an exclusive pump be provided to transfer the pre-treated bilge water from the oily bilge water holding tank to the oily water separator so as not to mix the pre-treated bilge water with untreated oily bilge water.
5.6 Heating arrangement
5.6.1 Heating arrangement for the bilge primary tank to facilitate separation of oil.
5.6.2 Heating arrangement for the waste oil tank to vaporize water and facilitate incineration.