Cooling system

The main function of the engine cooling system is to cool the metal adjacent to the combustion chamber. But during the operation cooling is also necessary to cool scavenging air, lubricating oil, exhaust manifold, crosshead guides, etc. The cooling media used in cooling are fresh and sea water, lubricating oil and scavenging air.

The cooling system which is used more often is the closed circuit system consisting of a primary (fresh water) circuit and a secondary (sea water) circuit. In this case sea water is used for cooling fresh water, oil and scavenging air.

The water enters the bottom of each cylinder jacket, then it flows upward, passes into the cylinder head, the exhaust valve cage, exhaust manifold jacket and after that it gets into the thermostat. This temperature regulator delivers part of the water to the cooler and the rest of it to the circulating pump to be recirculated.

The pistons are usually cooled with fresh water or oil. If the pistons are cooled with water the piston cooling system is separate from the jacket system. Cooling the pistons with oil eliminates troubles due to leakage of water into the lubricating oil. In both cases sea water is used only in coolers, through which the fresh water and oil pass leaving the engine.

The use of fresh water (as cooling medium) reduces scale formation, corrosion. And besides it is possible to keep (maintain) correct temperature of cooling water.

Emergency Repair in a Foreign Port

Mr Smith: How do you do. I’m Robert Smith from the ship repairing company. We have got information that your ship needs some repairs and I’m here to discuss the matter.

Ch. Eng: How do you do. I’m Chief Engineer of the ship. My name is …

Mr Smith: Glad to meet you, Mr …. Please tell me what kind of repairs you need.

Ch. Eng: First of all our trawl winch is out of order. It is necessary to replace the bronze bearings of the warp drums.

Mr Smith: OK. We can do it. Anything else ?

Ch. Eng: Oh yes. There are some repairs to the main engine and the steam boiler.

Mr Smith: What’s wrong with your main engine?

Ch. Eng: You see, the expansion joints connecting the turbocharger and the exhaust manifold are in bad repair. We tried welding but with poor results.

Mr Smith: Well, that’s clear. In this case we will replace the failed ones completely. And what’s the matter with your steam boiler?

Ch. Eng: I think it’s necessary to replace the fuel oil priming pump and to overhaul the feed pump valve chest too.

Mr Smith: In order to determine the scope of the repairs I’d like to survey the damages. Will you show me the way, please?

Ch. Eng: Oh yes, of course. Follow me, please.

Checking the marine equipment for pollution prevention

Inspector: Good morning. I’m an inspector of the Port State Control. I’d like to check the equipment and documents relating to (concerning) marine pollution prevention.

Chief Eng: Good morning, Inspector. I’m the Chief Engineer. I’m ready to show you everything and to answer all your questions.

Inspector: First I’d like to see your International Oil Pollution Prevention Certificate.

Chief Eng: Here you are. The annual survey was held a month ago.

Inspector: Yes, I see. Your International Certificate is valid. What separating and filtering equipment do you have on board?

Chief Eng: We have an oily water separating equipment producing effluent with oil content not exceeding 15 ppm.

Inspector: What type of control system do you have?

Chief Eng: Our control system includes 15ppm alarm and automatic stopping device.

Inspector: Do you have oil residue (sludge) storage tanks?

Chief Eng: Yes, we have two tanks with the total capacity of 10m³.

Inspector: What do you do with sewage and garbage?

Chief Eng: We have the sewage treatment system and the incinerator on board.

Inspector: Do you keep an Oil Record Book?

Chief Eng: Certainly. Here you are, please. We make all necessary entries. You can check them.

Inspector: I see your ship is equipped in accordance with the provisions of the International convention for the prevention of Pollution from Ships. Thank you, Chief.

Chief Eng: You are welcome.