OWS Page 66-67 Flashcards
Sketch an oily water separator system that complies with present legislation (8)
- With reference to the disposal of bilge water from machinery spaces:
e. Explain when it is NOT permissible to discharge the bilge water overboard, even via an oily water separator (8)
f. State the maximum permissible oil content of the overboard discharge (2)
g. Identify the documentation to be completed and state by whom, following such an operation (6)
- With reference to the disposal of bilge water from machinery spaces:
e. Explain when it is NOT permissible to discharge the bilge water overboard, even via an oily water separator (8)
• When the ship is in port, alongside
• When the ship is at anchor
• When the ship is not underway
• If there is no oil monitoring equipment fitted
f. State the maximum permissible oil content of the overboard discharge (2)
Oil Content in Water Maximum 15PPM
g. Identify the documentation to be completed and state by whom, following such an operation (6)
The oil record book, ships logs. To be completed and signed by Chief Engineer and Master
- Describe the procedure for operating the oily water separator (6)
b) State two ways that the separator could be made to operate more efficiently (2)
- Describe the procedure for operating the oily water separator (6)
• Inform the bridge and chief engineer that you wish to discharge bilge water, upon approval log the start location within
the oil record book.
• Fill the oily water separator with fresh water to flush, test the alarm function ensuring that the discharge stops during
alarm state
• Sound the bilge holding tank and record this figure
• Start drawing from the bilge water holding tank, the separator must be in full-auto control
• Log the time when the discharge commenced, the starting volume of the bilge holding tank and location of the vessel
• After successfully discharging the required quantity stop discharge, close discharge valve and flush the oily water
separator with fresh water.
• Sound the bilge holding tank, record all recordings within the engine-room log and oil record book, inform the bridge once
the operation is complete
b) State two ways that the separator could be made to operate more efficiently (2)
• Heating the bilge water holding tank to aide in oil separation
• Automatic logging and tracking built into the oil water separator control
- Describe the procedure for using a static oily water separator to discharge bilge water overboard (8)
b) State the effect that each of the following would have on the efficiency of the separator
i) The addition of heat to the separator (2)
ii) Agitating the bilge water before its pumped (2)
- Describe the procedure for using a static oily water separator to discharge bilge water overboard (8)
• Inform the bridge and chief engineer that you wish to discharge bilge water, upon approval log the start location within
the oil record book.
• Fill the oily water separator with fresh water to flush, test the alarm function ensuring that the discharge stops during
alarm state
• Sound the bilge holding tank and record this figure
• Start drawing from the bilge water holding tank, the separator must be in full-auto control
• Log the time when the discharge commenced, the starting volume of the bilge holding tank and location of the vessel
• After successfully discharging the required quantity stop discharge, close discharge valve and flush the oily water
separator with fresh water.
• Sound the bilge holding tank, record all recordings within the engine-room log and oil record book, inform the bridge once
the operation is complete
b) State the effect that each of the following would have on the efficiency of the separator
i) The addition of heat to the separator (2)
Heating the influent reduces the viscosity of the continuous media causing better separation.
ii) Agitating the bilge water before its pumped (2)
The separator would be less efficient during separation due to contamination of the bilge water. A more contaminated mixture
containing used chemicals that are drained in the engine room is more difficult to completely separate than that of normal
bilge water.
- State four conditions to be complied with, in order that bilge water may be discharged overboard while vessel is in a special area
b. Describe an engine room bilge system that complies with current legislation
- State four conditions to be complied with, in order that bilge water may be discharged overboard while vessel is in a special area
• Vessel must be on route
• Oil content must not exceed 15ppm
• An approved filtering system must be used which has a monitoring system to monitor oil content
• The oil filtering equipment must also be fitted with an automatic shutdown process if oil content exceeds 15ppm
b. Describe an engine room bilge system that complies with current legislation
• An approved oily water separator is prepared by filling it with fresh water.
• Engine room bilges are pumped using a dedicated bilge pump through a strainer and a pump suction filter into a bilge holding
tank which has to have adequate space for the bilge water to be pumped into
• The bilge water is then held here until ready to pass through the oily water separator
• The oily water separator must be listed on the international oil prevention certificate (IOPC)
• The OWS must be fitted with an oil content monitoring system and an automatic shut down if content rises about 15ppm
• In the first stage of the separator, because of different densities, the oil and water start to separate due to gravity with the
oil rising to the top where it is automatically drained to the oil collecting tank
• The water leaves and enters the second stage (The coalescing section). This is where more oil and solids are separated from
the water with the aid of very fine filters. The oil with an oil content of 15ppm or below is then pumped overboard but if the
oil content exceeds 15ppm then it is sent back to the holding tank and a visual and sound alarm will go off in the ECR
