Maritime Knowledge Base
Browse questions and answers across marine machinery, merchant navy careers, shipboard operations and maritime glossary terms.
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Marine Machinery
Troubleshooting guides for pumps, boilers, purifiers, compressors and auxiliary systems.
Merchant Navy Careers
Questions about joining the merchant navy, exams, cadetships, ranks and sea-time.
Maritime Glossary
Plain-English definitions of shipping, engine-room, navigation and regulatory terms.
Shipboard Operations
Practical Q&A for watchkeeping, safety, maintenance routines and onboard documentation.
Results for "Exhaust valve"
Why is the exhaust temperature high on one main engine unit?
A high exhaust temperature on a single cylinder points to that unit's combustion, injection or exhaust valve — a deviation from the others is the key diagnostic clue.
Marine MachineryHow does a marine diesel engine work?
A marine diesel engine converts the chemical energy of fuel into rotary motion through compression ignition — here is the working principle and the two-stroke and four-stroke cycles.
Marine MachineryWhat is the difference between a two-stroke and a four-stroke marine engine?
Two-stroke and four-stroke marine engines differ in how many strokes complete a cycle, their speed and size, and the roles they play aboard ship.
Marine MachineryWhat is the difference between a purifier and a clarifier?
A purifier separates both water and solids from oil, while a clarifier removes only fine solids from oil that contains little or no water — often the two run in series.
Marine MachineryWhat is jacket cooling water in a marine engine?
Jacket cooling water is the treated fresh water circulated through the passages, or jackets, around an engine's cylinders to carry away combustion heat and keep it at its correct working temperature.
Marine MachineryWhat is scavenging in a two-stroke marine engine?
Scavenging is the process of pushing the burnt exhaust gases out of a two-stroke engine cylinder and replacing them with fresh air, ready for the next combustion cycle.
Marine MachineryWhat is an indicator diagram and what does it tell the engineer?
An indicator diagram plots the pressure inside an engine cylinder against volume or crank angle, letting the engineer assess the power, condition and faults of each cylinder.
Marine MachineryHow does a ship's fuel oil system store, treat and deliver fuel to the engine?
The fuel oil system takes bunkers from the storage tanks, settles and purifies them, heats heavy fuel to the right viscosity, and delivers clean fuel under pressure to the engine.
Marine MachineryWhy is my main engine jacket cooling water temperature high?
Working through high jacket-water temperature — flow, the cooler, the sea and central-cooling side, thermostats, air locks and load.
Marine MachineryHow does a marine boiler work?
A marine boiler generates steam by transferring heat to water — this covers the working principle and the difference between oil-fired and exhaust-gas boilers.
