LUBRICATING OIL SYSTEM

Diesel engine lubricating-oil systems
Fig. 23.18 shows representative lubricating-oil systems for a low-speed diesel engine. The lubricating-oil requirements are divided between two systems: cylinder oil, which is consumed within the cylinders and must be continually replaced; and circulating lubricating-oil, which lubricates and cools the bearings, and (usually) the pistons. The circulating oil is continuously cleaned by the lubricating-oil purifier.

Figure 23.18: Main engine lubricating oil systems for a motorship

The lubricating-oil circulating system draws suction from the engine sump tank, which is built into the ship's double bottom. The suction bellmouth is located slightly above the sump bottom to avoid drawing in any settled water or sediment. The oil is drawn through a suction strainer by the lubricating-oil circulating pump, and then discharged through a finer strainer and the lubricating-oil cooler. A lubricating-oil cooler bypass valve is fitted to control the temperature of the oil supplied to the engine. The lubricating oil is then fed to the bearing-oil manifolds, the turbocharger bearings, and the hydraulic governor and control circuits.
The cylinder-oil system is used on crosshead engines and some trunk-piston engines. The cylinder oil is high-viscosity oil used to lubricate the piston rings and cylinder liner. It has a total base number...

THE PROPULSION OF THE SHIP

Marine propulsion is the mechanism or system used to move a ship or boat across water. While paddles and sails are still used on some smaller boats, most modern ships are propelled by mechanical systems consisting a motor or engine turning a propeller, or less frequently, in jet drives, an impeller. Marine engineering is the discipline concerned with the design of marine propulsion systems.
Steam engines were the first mechanical engines used in marine propulsion, but have mostly been replaced by two-stroke or four-stroke diesel engines, outboard motors, and gas turbine engines on faster ships. Nuclear reactors producing steam are used to propel warships and icebreakers, and there have been attempts to utilize them to power commercial vessels. Electric motors have been used on submarines and electric boats and have been proposed for energy-efficient propulsion.^[1]

THE SHIP'S ENGINE

 At this video you may see what is happening on an enginge room...