Marine Engineering and Ship Machinery
Scope
Marine Engineering and Ship Machinery tests the main propulsion plant, auxiliaries, pumps, boilers, fuel and lubricating oil systems, cooling, watchkeeping parameters and pollution-prevention equipment. The rating must recognise normal readings and act on abnormal ones.
Core rules
- A two-stroke slow-speed main engine uses scavenging and a turbocharger; starting air turns the engine before fuel is admitted.
- Jacket-water cooling removes heat from liners and heads; lubricating oil reduces friction and carries heat away.
- Fuel purifiers remove water and solids; the oily-water separator must alarm at 15 ppm and stop overboard discharge above that limit.
- Boiler safety valves, low-water alarms and flame failure trips must never be isolated.
- UMS alarms and dead-man alarms must be tested at the required intervals and never bypassed.
Worked example
An engine develops 8,000 kW at a specific fuel consumption of 180 g/kWh. Daily fuel use is 8,000 × 180 = 1,440,000 g/h = 1,440 kg/h. Over 24 hours: 1,440 × 24 = 34,560 kg, or 34.56 tonnes per day. Add a margin only if the question asks for it.
Traps
Mixing fuel-oil and lubricating-oil figures, treating the 15 ppm alarm as a target rather than a limit, and running a boiler with a low-water condition are serious errors. Also check units: g/kWh, kg/h and t/day are different.