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 "Lubricating oil"
Why is the main engine lubricating oil pressure low?
Low lubricating oil pressure is a serious alarm that threatens the bearings — the cause is usually in the pump, the filters, the oil itself, or a leak.
Marine MachineryHow does a marine centrifugal oil purifier work?
A marine purifier cleans fuel and lubricating oil by spinning it at high speed so that water and solids separate out — here is the working principle.
Marine MachineryWhat causes a crankcase explosion in a marine engine?
Crankcase explosions are caused by oil mist igniting after a hotspot overheats the lubricating oil — understanding the mechanism is key to preventing them.
Marine MachineryWhy is my fuel or oil purifier not separating properly?
The usual causes of poor purifier separation — feed rate, temperature, gravity disc and water seal, sludge and bowl condition — and how to work through them one at a time.
Shipboard OperationsWhat should be checked during engine-room watchkeeping rounds?
How to make an engine-room round count — comparing live readings against normal ranges and catching trends before they become failures.
Maritime GlossaryWhat is deadweight tonnage (DWT)?
Deadweight tonnage defined — the total weight a ship can carry — and how it differs from displacement and gross tonnage.
Marine MachineryWhat causes a scavenge fire in a two-stroke marine engine?
A scavenge fire is the ignition of accumulated oil and carbon in the scavenge spaces of a two-stroke engine — here is why it happens and how to respond.
Marine MachineryWhy won't the main engine start on air?
A main engine that turns on air but will not fire, or will not turn at all, points to a short list of common causes across the starting-air, fuel and control systems.
Marine MachineryHow do you recover from a blackout (total loss of electrical power)?
A blackout is the total loss of electrical power on a ship — recovery depends on the emergency generator, restarting the main plant and restoring services in the right order.
Marine MachineryHow does a marine engine turbocharger work?
A turbocharger uses the energy of the engine's exhaust gas to drive a compressor that forces more air into the cylinders, greatly increasing power and efficiency.
Shipboard OperationsWhat is a draught survey and how is cargo weight calculated?
A draught survey determines the weight of bulk cargo loaded or discharged by measuring the ship's draughts and calculating the change in its displacement.
Marine MachineryWhat is a central cooling system on a ship and why is it used?
A central cooling system uses seawater to cool a closed freshwater circuit, which in turn cools the machinery — reducing seawater corrosion and fouling in the equipment.
Marine MachineryWhat is a thrust bearing or thrust block and what does it do?
The thrust bearing, or thrust block, absorbs the forward or astern thrust developed by the propeller and transmits it to the ship's hull, so the thrust actually drives the ship.
Marine MachineryWhat is a bearing and what types are used in marine engines?
A bearing supports and locates a rotating shaft while allowing it to turn with little friction — marine engines rely on plain white-metal bearings lubricated by an oil film.
Marine MachineryWhat is the stern tube and stern tube seal on a ship?
The stern tube is the tube through which the propeller shaft passes out of the hull; it carries the aft bearing and a seal that keeps seawater out and lubricant in.
Marine MachineryHow does a marine incinerator work and what can it burn?
A marine incinerator burns the ship's waste oils, sludge and solid garbage in a combustion chamber, subject to MARPOL rules on what may be incinerated and where.
