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 "Hot work"
What is a hot work permit and when is it needed?
A hot work permit controls any work involving heat, flame or sparks outside a designated safe area, confirming the space is gas-free and fire precautions are in place.
Shipboard OperationsWhat is a permit to work (PTW) system on ships?
A permit to work is a formal written authorisation that controls hazardous, non-routine jobs by confirming the hazards are assessed and the right precautions are in place.
Shipboard OperationsWhat is a toolbox talk and when is it done?
What a toolbox talk is, when it happens before shipboard work, and how it turns the risk assessment and permit into a shared plan.
Shipboard OperationsWhat are the key steps in a safe bunkering operation?
The essentials of safe bunkering — the agreed plan and checklist, scuppers and SOPEP readiness, communication, monitoring and verifying the figures.
Shipboard OperationsWhat is a risk assessment on a ship and how is it done?
A shipboard risk assessment systematically identifies the hazards of a task, evaluates the risk and puts controls in place before the work begins.
Shipboard OperationsHow is a cargo tank cleaned on a tanker?
Cargo tanks are cleaned with fixed or portable washing machines using water or crude oil, followed by draining, gas-freeing and ventilation, before a change of cargo, entry or repair.
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 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.
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.
Marine MachineryHow does a marine fresh water generator (evaporator) work?
A fresh water generator makes drinking and technical water from seawater by boiling it under vacuum using waste heat from the engine, then condensing the vapour.
Marine MachineryHow does a marine air compressor work and why is it needed?
A marine air compressor squeezes air in stages to high pressure and stores it in receivers, chiefly to provide the starting air that turns large diesel engines over.
Marine MachineryHow does a ship's refrigeration plant work?
A marine refrigeration plant uses the vapour-compression cycle to move heat out of provision rooms or cargo spaces, keeping food and cargo cold at sea.
Shipboard OperationsHow does a fixed CO2 flooding fire-extinguishing system work?
A fixed CO2 system extinguishes a fire in a protected space such as the engine room by flooding it with carbon dioxide, which displaces the oxygen the fire needs — after everyone is evacuated.
Marine MachineryHow does a marine heat exchanger work?
A heat exchanger transfers heat from one fluid to another through a dividing wall without letting them mix — used all over a ship to cool engines, oil and air.
Shipboard OperationsWhat safety precautions are taken for working aloft on a ship?
Working aloft — up the mast, funnel or high structures — demands a permit, a safety harness, secured tools, and control of hazards such as radar, whistle and overside work.
Marine MachineryWhy is my marine fuel pump showing low pressure?
A structured checklist for low fuel-pump pressure — suction restrictions, air ingress, relief valves, worn elements and viscosity — before you touch the set point.
Merchant Navy CareersWhat is a cadetship and how long does it last?
What a merchant-navy cadetship involves, how long the sea phase lasts, and why the Training Record Book matters.
Shipboard OperationsWhat is an inert gas system on a tanker and why is it needed?
An inert gas system fills a tanker's cargo tanks with oxygen-poor gas so the atmosphere cannot support combustion, preventing explosions in and around the cargo.
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 MachineryWhy 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 MachineryWhy does the auxiliary boiler flame keep failing or the burner keep tripping?
Repeated boiler flame failure trips the burner on the flame monitor — the causes run through the fuel, the ignition, the air and the flame-detection system.
Merchant Navy CareersWhat is a training record book (TRB) for a cadet?
A training record book is the structured logbook in which a cadet records the practical training tasks completed aboard ship, signed off by officers, as evidence for certification.
Marine MachineryWhat is cylinder lubrication in a two-stroke marine engine?
Cylinder lubrication is the separate oil supply fed onto the liner of large two-stroke engines to lubricate, neutralise fuel acids and keep the surfaces clean.
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 MachineryWhy does a marine centrifugal pump lose suction or stop pumping?
A centrifugal pump that loses suction has usually lost its prime or drawn in air — the causes lie in air leaks, blocked suctions, low levels and cavitation.
Marine MachineryWhy is boiler water treated on a ship and how?
Boiler water is chemically treated and tested to prevent scale, corrosion and carryover, which would damage the boiler, reduce its efficiency and threaten safety.
