Maritime Knowledge Base

What 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.

What 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.

What 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.

What is a near miss on a ship and why is reporting it important?

A near miss is an event that could have caused injury, damage or pollution but happened not to — reporting them lets a ship correct hazards before they cause a real accident.

How do I join the Merchant Navy in India?

The main DG Shipping-approved routes for Indian candidates — IMU CET degrees, sponsored DNS cadetships, and GME after engineering — with eligibility and the pitfalls to avoid.

What 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.

Why 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.

Why 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.

Why won't my marine air compressor build pressure?

A first-principles check for a compressor that runs but won't build pressure — valves, unloader, leaks, rings and cooling.

What causes a fluctuating water level in a marine boiler?

Why a boiler gauge glass swings — priming, foaming, load swings, feed control and level-sensor faults — and the safety response when the true level is in doubt.

Maritime Glossary

What is ballast water and why is it managed?

What ballast water is, why ships carry it, and why it is now exchanged or treated under the Ballast Water Management Convention.

Why 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.

Is the merchant navy a good career choice?

The merchant navy offers high pay, tax advantages, world travel and structured progression, balanced against long periods away from home — here is an honest assessment.

What is the man overboard (MOB) procedure on a ship?

When someone falls overboard, immediate, drilled actions — raising the alarm, marking the position and turning the ship back — give the best chance of recovery.

What 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.

What 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.

Why 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.

What is a Shipboard Oil Pollution Emergency Plan (SOPEP)?

SOPEP is the Shipboard Oil Pollution Emergency Plan, a MARPOL-required plan that tells the crew how to report and respond to an oil spill from the ship.

What are the SOLAS lifeboat and abandon ship drill requirements?

SOLAS requires regular abandon-ship and fire drills, with musters, equipment checks and the lowering and manoeuvring of lifeboats at defined intervals.

What causes a marine engine turbocharger to surge?

Turbocharger surging is a violent, audible instability of the airflow through the compressor — it signals a mismatch between the turbocharger and the engine's demand.

What medical and eyesight standards are required to join the merchant navy?

Seafarers must pass a seafarer medical examination covering general fitness, eyesight and colour vision, and hearing — the standards protect safety at sea.

What is a snap-back zone and why is mooring so dangerous?

A snap-back zone is the area a mooring line may whip through if it parts under tension — mooring decks are among the most dangerous places on a ship.

How 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.

What is the abandon ship procedure and when is it ordered?

Abandoning ship is the last resort when a vessel can no longer be saved — it follows a drilled sequence of muster, boarding survival craft and summoning rescue.

Why does the oily water separator 15 ppm bilge alarm keep activating?

The 15 ppm alarm on the oily water separator stops overboard discharge when the oil content is too high — the causes lie in the separator, the monitor or the feed.

Why 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.

How is a navigation (bridge) watch properly handed over?

A bridge watch handover requires the relieving officer to be fully oriented — position, traffic, course and dangers — before accepting the watch, and never mid-manoeuvre.

How 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.

What are the ranks and hierarchy in the merchant navy?

A merchant ship's crew is organised into the deck, engine and catering departments, each with a clear hierarchy of officers and ratings under the overall command of the Master.

What are the four stages of passage planning (appraisal, planning, execution, monitoring)?

Passage planning follows four stages — appraisal, planning, execution and monitoring — that together prepare and carry out a safe voyage from berth to berth.

Can women join the merchant navy and what roles can they hold?

Yes — women can and do serve in every department and rank of the merchant navy, from cadet to Master and chief engineer, and the industry is actively working to recruit more.

What shore-based jobs can experienced seafarers move into?

Experienced seafarers are in demand ashore for a wide range of maritime roles — surveying, pilotage, ship management, training, insurance and port work — where their sea experience is essential.

What 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.

What is the emergency procedure if the steering gear fails?

Steering gear failure is a serious emergency handled by switching to the standby power unit or emergency steering and warning other ships, backed by SOLAS redundancy.

What 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.

What is crude oil washing (COW) on a tanker?

Crude oil washing cleans a tanker's cargo tanks during discharge by spraying them with the crude cargo itself, which dissolves clingage and reduces residue, sludge and pollution.

How does a ship's sewage treatment plant work?

A marine sewage treatment plant breaks down the ship's sewage — usually biologically — and disinfects it so that the treated effluent meets MARPOL Annex IV discharge standards.

How 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.

How does a marine centrifugal pump work?

A centrifugal pump moves liquid by spinning it with an impeller, which throws the liquid outward and converts its speed into pressure — the most common type of pump aboard ship.

Why 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.

What is cavitation in pumps and propellers?

Cavitation is the forming and violent collapse of vapour bubbles in a liquid when local pressure falls too low — it erodes metal, causes noise and vibration, and reduces efficiency.

What is a Safety Management System (SMS) on a ship?

A Safety Management System is the documented set of policies and procedures, required by the ISM Code, by which a company manages the safe operation of its ships and prevention of pollution.

What is lock-out tag-out (LOTO) and why is it used aboard ship?

Lock-out tag-out is the practice of isolating a machine's energy sources and physically locking and tagging them off before maintenance, so it cannot be started or energised while someone is working on it.

What 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.

What 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.

What is bridge resource management (BRM) and why does it matter?

Bridge resource management is the effective use of all the people, equipment and information available on the bridge to navigate safely, reduce human error and prevent accidents.

What 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.