I:\CIRC\MEPC\01\642.DOC 

INTERNATIONAL MARITIME ORGANIZATION

4 ALBERT EMBANKMENT 

LONDON SE1 7SR 

Telephone: 020 7735 7611 

Fax: 020 7587 3210 

IMO 

E

Ref. T5/1.01 MEPC.1/Circ.642 

 12 November 2008 

2008 REVISED GUIDELINES FOR SYSTEMS FOR HANDLING OILY WASTES IN 

MACHINERY SPACES OF SHIPS INCORPORATING GUIDANCE 

NOTES FOR AN INTEGRATED BILGE WATER TREATMENT SYSTEM (IBTS) 

1 MARPOL Annex I contains certain regulations and unified interpretations related to 

equipment for the storage, handling and disposal of oily residues (sludge) and engine-room oily bilge 

water. 

2 In order to facilitate the work of Administrations on systems for handling oily wastes in 

machinery spaces of ships, the Marine Environment Protection Committee (MEPC) has continuously 

reviewed the available technologies for fulfilment of the Convention requirements. 

3 The Revised Guidelines for systems for handling oily wastes in machinery spaces of ships 

incorporating guidance notes for an integrated bilge water system (IBTS) appended to 

MEPC.1/Circ.511 were adopted by MEPC 54 as guidance for Administrations, shipowners and 

shipbuilders for consideration in achieving an efficient and effective system for the handling of oily 

bilge water and oily residues for ships taking into account the entry into force of the revised 

MARPOL Annex I on 1 January 2007. 

4 Recognizing that the entry into force of MARPOL Annex VI, including its provisions for 

shipboard incineration of sludge oil generated during the normal operation of a ship, has called for a 

further revision of the Guidelines, as contained in MEPC.1/Circ.511, the Marine Environment 

Protection Committee, at its fifty-eighth session (6 to 10 October 2008), approved the 2008 Revised 

Guidelines for systems for handling oily wastes in machinery spaces of ships incorporating Guidance 

notes for an integrated bilge water treatment system (IBTS) (MEPC 58/23, paragraph 10.45). 

The 2008 Revised Guidelines, set out in the annex, supersede and replace the Revised Guidelines 

appended to MEPC.1/Circ.511. 

5 To ensure compliance with the provisions on oil residue (sludge) collection and disposal of 

MARPOL Annex I, the process of regeneration of fuel oil from oil residue (sludge) has been defined 

and included in the Guidance notes for an integrated bilge water system (IBTS) appended to the 

Guidelines. 

6 A recommendation regarding internal drain tanks for oily residue (sludge) and other oily 

residues, which can only be discharged to the vesselís oily residue (sludge) tanks has been included 

in order to simplify the required records in the Oil Record Book. 

7 Member Governments are invited to apply the revised Guidelines and to bring them to the 

attention of interested parties, including recognized organizations. 

*** 

MEPC.1/Circ.642 

I:\CIRC\MEPC\01\642.doc 

ANNEX 

2008 REVISED GUIDELINES FOR SYSTEMS FOR HANDLING OILY WASTES 

IN MACHINERY SPACES OF SHIPS INCORPORATING GUIDANCE NOTES FOR AN 

INTEGRATED BILGE WATER TREATMENT SYSTEM (IBTS) 

1 MARPOL Annex I contains certain regulations and unified interpretations related to 

equipment for the storage, handling and disposal of oily residues (sludge) and oily bilge water. 

2 In the continuous review by the Marine Environment Protection Committee (MEPC) of 

appropriate technology for fulfilment of the Convention requirements, substantial information has 

been collected which is valuable in the design, approval and surveying of installations in 

engine-rooms for systems handling oily bilge water, and oily residues (sludge), but this does not 

form part of the Convention regulations or the related interpretations. 

3 The MEPC decided that this information is, nevertheless, of substantial value to 

Administrations, shipowners and shipbuilders and, accordingly, decided that dissemination of the 

information should be in the format of an MEPC circular. 

4 The information contained in these Guidelines should be regarded as guidance in achieving 

an efficient and effective system for the handling of oily bilge water and oily residues (sludge) for 

new buildings and, where applicable and reasonable, for ships which are in service. The information 

should be considered in conjunction with specific conditions and circumstances, shipownersí and 

shipbuildersí practices, classification society rules, Administration requirements, etc., applicable to 

specific ships. 

4.1 The unified interpretations of MARPOL should further be considered in achieving an 

efficient and effective system for the handling of oily water bilge and oil residue (sludge). 

5 Definitions for the purpose of the Guidelines 

5.1 Oily waste means oil residues (sludge) and oily bilge water. 

5.2 Oil residue (sludge) means the residual waste oil products such as those resulting from the 

purification of fuel or lubricating oil from main or auxiliary machinery or separated waste oil from 

bilge water separators, oil filtering equipment or oil collected in drip trays, and waste hydraulic and 

lubricating oils. 

5.3 Oil residue (sludge) tanks are the tanks which hold oil residue (sludge) directly from which 

oil residue (sludge) may be disposed through the standard discharge connection or any other 

approved means of disposal. 

5.4 Oily bilge water holding tanks are tanks collecting oily bilge water prior to its discharge, 

transfer or disposal. 

5.5 Regulations referred to in these Guidelines are those contained in MARPOL Annex I adopted 

by resolution MEPC.117(52). 
MEPC.1/Circ.642 

ANNEX 

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5.6 Oil residue (sludge) incineration systems are systems proving incineration of oil residue 

(sludge) generated on board seagoing ships. Oil residue (sludge) incineration systems could be: 

.1 main and auxiliary steam boilers with appropriate oil residue (sludge) processing 

systems; 

.2 heaters of thermal fluid systems with appropriate oil residue (sludge) processing 

systems; 

.3 incinerators with appropriate oil residue (sludge) processing systems designed for 

sludge incineration; or 

.4 inert gas systems with appropriate oil residue (sludge) processing systems. 

Oil residue (sludge) incineration systems shall conform to regulation 16 in MARPOL Annex VI. 

5.7 Oil residue (sludge) drain tanks are: 

.1 tanks intended to receive separated sludge from purifiers and other oil residue 

(sludge) drains; 

.2 tanks without any means for disposal of sludge as listed in items 3.2 and 4 in the 

Supplement to the IOPP Certificate, and drains; and 

.3 tanks with suction connection for a sludge collecting pump only capable of 

discharging to the oil residue (sludge) tank(s) listed in item 3.1 in the Supplement to 

the IOPP Certificate. 

5.8 Sludge collecting pumps are pumps capable of taking suction from any oil residue (sludge) 

producing equipment or tank, other than an oil residue (sludge) tank(s), and discharging only to oil 

residue (sludge) tank(s). 

5.9 Separated sludge is sludge resulting from purification of fuel and lubricating oil. 

6 Collection and storage of oil residue (sludge) and oily bilge water 

6.1 An oil residue (sludge) tank or tanks are mandatory under regulation 12 in the revised 

MARPOL Annex I. 

6.2 An oily bilge water holding tank is arranged to receive the daily generation of oily bilge 

water before this water is discharged ashore or discharged through the 15 ppm bilge separator 

overboard. An oily bilge water holding tank is not mandatory, but will enable ships to operate safely 

during port visits, during operation in special areas and coastal waters and during periods of 

maintenance of the 15 ppm bilge separator. 

6.3 An oily bilge water holding tank will also provide additional safeguards in the purification of 

oily bilge water should quick-separating detergents be used for cleaning purposes. 

6.4 Oily bilge water holding tanks shall, if fitted, be noted in the Supplement to the 

IOPP Certificate. 
MEPC.1/Circ.642 

ANNEX 

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7 Arrangements for oil residue (sludge) and oily bilge water tanks 

7.1 Tanks for the purposes mentioned above should be arranged to satisfy the intended service of 

the ship. 

7.2 Oil residue (sludge) tanks may be separate and independent but may also be combined, as 

suitable, depending on the size and the service of the ship. 

7.3 The merits of arranging an independent tank for the collection of separated sludge should be 

considered, having regard to the smaller tank volume that needs to have cleaning and heating 

arrangements and the reduced space requirement for tank capacity that should preferably be arranged 

above the tank top. 

7.4 If an oily bilge water holding tank is arranged, it should be separate and independent from 

other tanks for the collection of oil residue (sludge). 

7.5 Ships operating with heavy fuel oil of a relative density greater than 0.94 at 15°C should be 

provided with an oily bilge water holding tank of adequate capacity and fitted with heating facilities 

to preheat the oily mixture prior to the discharge of the tankís contents into the sea through 

the 15 ppm bilge separator. 

8 Size of oily residue (sludge) and oily bilge water tanks 

8.1 Tanks for collection of oily waste from various functions in the engine-room should have 

adequate capacity, having regard to the intended type of service of the ship. The information given 

below will provide guidance in this respect, but all other aspects applicable to the specific vessel 

trading pattern and time in port should additionally be taken into account. 

8.2 The recommended capacity for oil residue (sludge) tanks is specified in the interpretations to 

regulation 12. 

8.3 Oily bilge water holding tanks, if fitted, should have a capacity that provides to the ship the 

flexibility of operation in ports, coastal waters and special areas, without the need to discharge 

de-oiled water overboard. The operational merit of not having to operate the 15 ppm bilge separator 

frequently should also be considered. The recommended capacity of oily bilge water holding tanks 

should be as follows: 

Main engine rating (kW) capacity (m3) 

up to 1,000 4 

Above 1,000 up to 20,000 P/250 

Above 20,000 40+P/500 

Where: P = main engine rating in kW. 

For ships adopting IBTS, the capacity oily bilge water holding tanks may be reduced. 
MEPC.1/Circ.642 

ANNEX 

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9 Pumping, piping and discharge systems in machinery spaces 

9.1 On board ships, the propulsion systems of which are operated by heavy fuel oil, the following 

guidelines are provided for the piping system comprising the plant components for the treatment and 

storage of oily bilge water, oil residue (sludge), drain and leakage oil and exhausted oil. 

9.2 The effluent from the 15 ppm bilge separators should be capable of being recycled to the oily 

bilge or oily bilge water holding tank. 

9.3 If an integral pump is fitted, the discharge must not bypass the 15 ppm bilge separator. 

9.4 The discharge piping system of the 15 ppm bilge water separator should be completely 

separate from the bilge pumping and ballast water system except the recycling line referred to in 

paragraph 9.2. 

9.5 Discharge piping systems fitted to secure the safety of the ship in emergency situations, such 

as fire or flooding, should efficiently and promptly tackle such emergencies and therefore should be 

available at all times in order to comply with the provisions of SOLAS regulation II-1/21. 

Accordingly, the bilge overboard discharges should not be blanked off and remain operational at all times.

9.6 The shipís discharge pipeline for oily residue (sludge) to the standard discharge connection 

should not be connected to any system other than supplying those means of disposal to be listed in 

the IOPP supplement. 

9.7 The separated dirty water and exhausted control water of fuel oil purifiers should be 

discharged into a particular tank for this purpose in order to minimize the influx to the oil residue 

(sludge) drain tank for separated sludge. This particular tank should be located above the double 

bottom for the purpose of facilitating its drain without the need of a drain pump. If dirty water and 

exhausted control water from purifiers is not discharged to a particular tank, and in lieu of this to a 

oil residue (sludge) drain tank for separated sludge, the tank should be located above the double 

bottom for the purpose of the aforementioned draining facilities. 

9.8 Piping to and from sludge tanks shall have no direct connection overboard, other than the 

standard discharge connection required by regulation 13. 

10 Systems for separated sludge 

10.1 Tanks for separated sludge and their pipework 

Tanks for separated sludge, their pipework and pumps should be designed as follows: 

10.1.1 Size of tanks: see paragraph 8. 

10.1.2 Tank heating system 

Tanks for separated sludge should be equipped with tank heating systems. The heating pipes should 

be arranged such that, seen from the heating inlet, to start with they are arranged in a way of the 

boundaries and then across the whole bottom area sufficiently high, in order to avoid being covered 

totally by sediments in the tank. The tank heating system should be designed such as to enable 

heating of the oil sludge up to 60°C. The suction line from the sludge tank to the pump should be 

provided with heat tracing. 
MEPC.1/Circ.642 

ANNEX 

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10.1.3 Oil residue (sludge) drain tank 

The tank for separated sludge or other waste oils may be arranged as a separate oil residue (sludge) 

drain tank. 

10.1.4 Pipelines from the heavy fuel oil purifier to the tank 

Whenever possible, the oil residue (sludge) tank should be located below the heavy fuel oil purifier. 

If this is not possible, the oil residue (sludge) holding tank should be situated close to the heavy fuel 

oil purifier in such a way that the discharge line to the tank can be installed at the maximum gradient. 

The pipelines should, wherever possible, be straight or fitted with large radius elbows. 

10.1.5 Suction line from the oil residue (sludge) tank 

The pump suction should be arranged so that the path to the suction opening is as short as possible; 

or the oil residue (sludge) tank should be mounted or designed, so that the oil residue (sludge) moves 

down a slope towards the suction opening. The openings should be placed as wide as possible in the 

frames above the tank bottom in such a way that the oil sludge has free access to the suction line. 

10.1.6 Oil residue (sludge) collecting pump and pressure lines 

The pump should be suitable for use with high viscosity oil residue (sludge), e.g., ìself-priming 

displacement pumpî, with suitable means for protection against dry running. It should have a 

sufficient total head, and delivery rate to facilitate the transfer of the daily sludge production 

onboard. 

10.1.7 Oil residue (sludge) discharge pump and pressure lines 

The pump should be suitable for use with high viscosity oil sludge, e.g., ìself-priming displacement 

pumpî, with suitable means for protection against dry running. It should have a sufficient total head, 

and be capable of discharging the tank within 4 to 8 hours. 

The pressure side of the pump should only be connected to the standard connection on deck and to 

oil residue (sludge) tank(s) and to other sludge disposal means as listed in item 3.2 in the Supplement 

to the IOPP Certificate. 

10.1.8 Oil residue (sludge) tank design to facilitate cleaning 

Access holes should be arranged so that all areas of the tank can be cleaned. An access hole should 

be sited on top of the tank to facilitate the use of a portable pump. 

10.1.9 Steaming-out lines 

The oil residue (sludge) tanks should be fitted with steaming-out lines for cleaning. 
MEPC.1/Circ.642 

ANNEX 

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11 Example of an on-board system for oil residue (sludge) incineration 

11.1 General 

Oil residue (sludge) from oil residue (sludge) tanks may be incinerated in incineration systems 

onboard. Oil residue (sludge) tanks are not a means for disposal of oil residue (sludge), but for 

retention of oil residue (sludge) for disposal. 

11.2 Oil residue (sludge) incineration systems 

An oil residue (sludge) incineration system may be composed of: 

.1 steam boiler or heater of thermal fluid systems or an incinerator; 

.2 oil burner; 

.3 oil sludge processing system; and 

.4 service tanks for oil residue (sludge). 

11.3 Oil residue (sludge) processing systems 

The oil sludge processing system consists of: 

.1 oil residue (sludge) tank intended as servicing the oil residue (sludge) sludge 

incinerating system; 

.2 oil residue (sludge) preheating system; 

.3 filter; and 

.4 homogenization system. 

11.4 Oil residue (sludge) service tank 

The oil residue (sludge) service tank should be listed under item 3.1 in the Supplement of the IOPP 

Certificate, as it is provided with means for drainage of water (disposal) and subsequent disposal of 

the oil residue (sludge) in the oil residue (sludge) incineration system. 

The oil residue (sludge) service tank should be provided in addition to the oil residue (sludge) tank 

for oil residue (sludge) and other waste oils. It should be equipped with suitable drainage facilities. 

With a view to improving combustibility and calorific value, a fuel oil supply connection should be 

provided. 

11.5 Homogenization system 

The homogenization system should assure that the entire contents of the oil residue (sludge) service 

tank should be processed into a homogenous and combustible mixture. This system should be put 

into operation following adequate draining of the tank. A device for continuous indication and 

monitoring of the water content of the oil sludge should be provided. 
MEPC.1/Circ.642 

ANNEX 

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APPENDIX 

GUIDANCE NOTES FOR AN INTEGRATED BILGE WATER 

TREATMENT SYSTEM (IBTS) 

1 Introduction 

1.1 Oily bilge water is generated by the leakage of water and oil from the equipment and piping 

or maintenance works resulting from the routine operation in machinery space of ships. Such leaked 

oil and water are usually mixed and collected on the tank top or bilge wells as oily bilge water. 

1.2 Oily bilge water shall be treated in accordance with the requirements of the Convention. 

The operation of such treatment, including the operation and maintenance of the oily water separator, 

is a heavy load for engineers onboard. 

1.3 After the revision of the Guidelines and Specifications for Pollution Prevention Equipment 

for Machinery Space Bilge of Ships adopted by resolution MEPC.107(49), the capability of oily 

water separators has been improved. However, the treatment process of oily bilge water with the 

improved equipment and the engineersí load will be basically unchanged as the amount of oily bilge 

water generated in ships has not been reduced. 

1.4 To promote the prevention of oil pollution from machinery spaces of ships and reduce the 

load of the engineers onboard, it is effective to minimize the amount of oily bilge water generated in 

machinery spaces. 

1.5 MEPC 54 noted the design with the concept of Integrated Bilge Water Treatment System 

(IBTS) which provides the means to minimize the amount of oily bilge water and process the oily 

bilge water and oil residue (sludge) as a drastic solution to prevent oil pollution from machinery 

spaces of ships. 

1.6 MEPC 54, in recognizing the need to disseminate the concept of IBTS, agreed to append the 

Guidance notes on IBTS to the revised Guidelines for systems for handling oily wastes in machinery 

spaces of ships. 

1.7 The purpose of these Guidance notes is to provide shipowners and shipbuilders with 

information to help in the design of ships incorporating the concept of IBTS. 

2 Concept of Integrated Bilge Water Treatment System (IBTS) 

The Integrated Bilge Water Treatment System (IBTS) is a system to minimize the amount of oily 

bilge water generated in machinery spaces by treating the leaked water and oil separately. It also 

provides an integrated means to process the oily bilge water and oil residue (sludge). 

3 Definitions for the purpose of the Guidance notes 

3.1 ìClean drainsî mean internal drains such as those resulting from the leakage of and 

condensate from equipment used for seawater, fresh water, steam, air conditioning, etc., which are 

not normally contaminated by oil. 
MEPC.1/Circ.642 

ANNEX 

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3.2 ìOily drainsî mean drains such as those resulting from the leakage of equipment used for oil 

and drains from equipment which under normal circumstances may contain oil. 

3.3 ìOily bilge waterî means water collected in the bilge wells or the tank top such as those 

resulting from the unexpected leakage from piping or the maintenance work in machinery spaces, 

which may be contaminated by oil. 

3.4 ìOil residue (sludge)î: refer to paragraph 5.2 of the revised Guidelines; includes oily drains. 

3.5 ìBilge primary tankî means a pre-treatment unit for separation of oily bilge water. 

3.6 ìClean water holding tankî means tanks which hold processed water from the oil filtering 

equipment. 

4 Outline of IBTS 

4.1 Collection of drains

4.1.1 Oily drains are collected through the fixed drainage arrangements to oil residue (sludge) 

tanks. 

4.1.2 Clean drains are collected through the fixed drainage arrangements to clean drain tanks. 

4.1.3 Oily drains and clean drains should be collected separately so as not to contaminate clean 

drains with oil. 

4.2 Pre-treatment of oily bilge water

To avoid feeding excessive oil to oil filtering equipment, oily bilge water in the bilge wells is 

transferred to the bilge primary tank for pre-separation of oil. The high oil content water is 

transferred to sludge tanks and the low oil content water is transferred to the bilge water holding 

tank. 

4.3 Discharge of oily bilge water

4.3.1 Oily bilge water in the bilge water holding tank is discharged overboard through the oily 

water separator in accordance with Regulation 14 of the Convention. 

4.3.2 Clean water which has been processed trough the oil filtering equipment may only be 

discharged through the 15 ppm bilge alarm combined with an automatic stopping device by means of 

a separate clean water pump. 

4.4 Discharge of clean drains

Clean drains may be discharged overboard directly through the discharge arrangement, independent 

from the system for oily bilge water or oil. 
MEPC.1/Circ.642 

ANNEX 

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4.5 Treatment of oil residue (sludge)

4.5.1 Oil residue (sludge) may be collected in separate tanks designated for fuel oil residues and 

lubrication oil residues respectively. 

4.5.2 Water in oil residue (sludge) may be evaporated by heating in the oil residue (sludge) service 

tanks. 

4.5.3 Oil residue (sludge) may be incinerated by the sludge incineration system or disposed of to 

the reception facilities through the standard discharge connection. 

4.6 Re-generating fuel oil from sludge

4.6.1 Oil residue (sludge) may be used onboard as re-generated fuel. Oil residue (sludge) is 

collected in an oil residue (sludge) tank prior to processing (disposal) back into the fuel oil system as 

re-generated fuel oil. 

4.6.2 Oily drains should be recorded in the oil record book as any other oil residue (sludge) 

collection. 

4.6.3 Re-generation of fuel oil from oil residue (sludge) should be an approved means of disposal 

of oil residue (sludge) according to the Supplement to the IOPP Certificate. 

4.6.4 The re-generating process may include filtration, decanting or purification to remove 

unwanted heavy parts from the oil residue (sludge). 

4.6.5 The re-generated fuel oil when used in a SECA must comply with SECA fuel oil quality 

requirements. 

4.6.6 The re-generated fuel is fed back into the vesselís fuel oil system at a rate equal to or less 

than the average sludge production on board. This is in order not to change the emission level of the 

exhaust when using the fuel oil with added re-generated fuel oil compared to using fuel oil as 

delivered without prior sludge separation. 

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. 
MEPC.1/Circ.642 

ANNEX 

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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. 

 From bilge pump 

To bilge water holding tank To oil residue (sludge) holding tank 

Figure 1 ñ 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. 
MEPC.1/Circ.642 

ANNEX 

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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. 

6 Example of IBTS 

A typical flow diagram of IBTS is shown in Figure 2. 
MEPC.1/Circ.642 

ANNEX 

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Figure 2 ñ Flow Diagram of Integrated Bilge Water Treatment System (IBTS) 

___________ 

Main engine air cooler air drain

Cooling fresh water, Sea water

Steam drain, Boiler water

Pump

Overboard 

Boiler FO 

settling tank

Boiler

Incinerator

Oil residue (sludge) 

service tank

Oil residue (sludge) 

tank

Oil residue (sludge) 

drain tank

Sludge collecting 

pump 

Pump

Pump

Bilge alarm

Bilge alarm

Pump

Pump

Oily water separator

Oily bilge-water 

Bilge well 

Overboard 

Clean drain tank

Engine-room scupper 

(leakage from pipelines)

Clean water 

tank

Bilge 

primary tank

Oily bilge water holding tank

Hydraulic oil pump & tank coaming drain

Waste oil pump & tank coaming drain

LO pump & tank coaming drain

Bilge equipment coaming drain

Main engine piston underside

Compressed air drain

Purifier sludge

Oil mist drain

Work shop drain

FO pump & tank coaming drain 

FO filter drain

FO drain tank

Pump 

Evaporated 

water

Reception 

facilities

Clean drains Oil residues (sludge) 

 Optional arrangements (not including the IBTS concept)