In motorships there are two main circuits, one salt , one fresh. The salt circuit is: sea inlet box (seachest) - pump(s) - f.w. coolers in series (first LT then HT) – turbo blower aftercoolers in parallel (if any) – provision condenser in parallel (if any) - overboard

In motorships the oil, after passing through main and motion bearings and oil-cooled pistons, etc., is either retained in the bedplate or flows by gravity to a sump tank. In either case, the oil pumps, which may be self￾priming, submerged centrifugal or rotary positive displacement, draw the oil through magnetic strainers and discharge to: filters - oil coolers - engine lubricating and/or cooling manifolds

Air at high pressure, i.e. at 25 bar or more, is required for starting main and auxiliary engines in motorships. Air at low pressure, say at 6 bar or less is required for much remote or temperature or pressure controlled equipment, for which purpose it must be clean and oil-free

A fire and bilge pump has suctions from sea, bilge main and engine room bilge, with discharges to fire main, oily water separator and overboard. A ballast pump has suctions from sea, ballast main, engine room , bilge direct and bilge main with discharges to overboard, the ballast main, the oily water separator and possibly, the main salt water circulating system

Learning Objectives The learning objectives of this section are to make all engineers, engine cadets and other crew members who are involved in the handling of fuels onboard, familiar with: – How to handle the fuel. – Take the necessary simple precautions by following test procedures

Learning Objectives The main objectives of this section are to make all engineers familiar with: Pre-treatment of marine fuels. Design criteria, or problems related to settling and service tanks. Draining of settling tanks. Preheating. Separation, purifier and clarifier. Sludge and sludge handling

The main objective of this section is to make you acquainted with the relevance of fuel parameters on: Abnormal ignition and combustion. Wear, piston ring collapse and breakage. Gas leakage. Ignition, combustion and exhaust gas emission. Engine damages and operational problems. Prevention of engine damages with off spec. fuels and to recognize their impact on the operation of marine diesel engines

3.2 Treatment of detergent type lubricating oils The main function of detergent lubricating oil is to keep solid contaminations in suspension and prevent both their agglomeration and deposition in the engine. This function reduces ring sticking, wears of piston rings and cylinder liners, and generally improves the cleanliness of the engine. agglomeration

3.3 Batch and continuous lubricating systems For small or medium units without a circulatory lubricating system, the oil is often treated on the batch system. As large a quantity of oil as possible is drained from the engine at intervals and run into a heating tank, the system being replenished with clean oil at the same time

Open systems using gravity tanks, etc., are rarely met nowadays and Figure 1.8 shows a characteristic arrangement of pressure tanks, calorifiers and pumps for a large ship. The fresh water pumps are self-priming, drawing from storage tanks and discharging through filters to a rising main, branched to give a cold supply and a hot supply in closed circuit through a calorifier. A tank kept under pressure by an external supply of compressed air rests on the system and provides the head necessary