Engine Room General (motor) — Most Asked Questions
24 questions asked about engine room general (motor) across the General and Fn 3 and Fn 4b papers, heaviest first.
Learn the system first
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1 FLOODING IN ENGINE ROOM WHAT TO DO?
Answer
Flooding drill is warn, pump and find: alarm the ship, get pumps on with position and time logged, and put men on the leak — not on the water.
- Inform bridge and chief at once; raise the engineer’s call and emergency alarm.
- Before starting the bilge pump log vessel position and start time; start a second pump if ingress is heavy.
- Put spare hands on finding the hole or burst pipe and repairing it while pumps run; reduce engine rpm.
- Change main seawater suction to emergency bilge suction; if the level still rises, guard motors against short circuit — and have the lifeboat ready if control is lost.
Surveyor follow-up: water is over the floor plates and rising with both bilge pumps running — what suction change do you order next?
Full theory: Marine Diesel Engine Starting & Running Troubles: Fault Trees, Knock Diagnosis & Emergency Response -
2 boiler alarm and trips??
Answer
Boiler alarms warn, trips act: low water kills the burner, flame failure shuts fuel, and pressure faults lift protection.
- Low-water alarm sounds first; at low-low level the burner trips and locks out — prove both by actually dropping the chamber level.
- Flame-failure alarm on low fuel pressure, bad burner or lost flame shuts the fuel valves so unburnt fuel cannot accumulate.
- High steam pressure, high water level, feed-pump failure and hotwell loss each raise their own alarm before damage.
- After any trip find the cause, refill and reset deliberately — never reset a low-water trip without seeing the level.
Surveyor follow-up: flame-failure trips repeatedly with fuel pressure normal — fuel or burner, and what do you check first?
Full theory: Boiler Safety Devices and Emergency Response -
3 Engine room Crane safeties
Answer
The crane is proved by limits, brakes and markings: every motion limited, every load braked fail-safe, SWL painted on.
- Limit switches on hoist, lower, travel and traverse, backed by mechanical stoppers if a switch fails.
- Electromagnetic brake releases only with power on — loss of power sets it automatically with the load hanging.
- Overload and load-limit switches trip the motor above rated capacity; rail guards, rough-weather locks and hook stowage fitted.
- Breakers at two places, clear SWL marking, and operation proved at list and trim.
Surveyor follow-up: the hoist limit fails its test with a load on — do you lower with the motor or land it another way?
Full theory: Deck Cranes — Three Motions, Level Luffing and Safety Features -
4 Power-operated sliding doors should be provided with a local audible alarm distinct from any other alarm in that area which shall sound for at least 5 seconds whenever the door is closed remotely but not more than 10 sec
Also asked: “Power-operated sliding doors should be provided with a local audible alarm distinct from any other alarm in that area which shall sound for at least 5 seconds whenever the door is closed remotely but not more than 10 seconds before the door begins to move. The sound should be audible until the door is completely closed”
Answer
Remote closure warns first: a unique local alarm sounds 5–10 seconds before the door moves and keeps sounding until shut.
- Alarm unlike any other in the area, mounted local to the door.
- Sounds 5–10 seconds before remote-powered movement starts — hand operation instead alarms only while moving.
- Keeps sounding until the door is fully shut; passenger and noisy spaces add a flashing visual signal.
- No alarm, no remote close — the door stays local until the sounder is proved.
Surveyor follow-up: alarm sounds but the door never moves — power, control or alarm fault, and what do you test first?
Full theory: Decks, Openings and Watertight Closing Appliances -
5 Which flywheel is bigger 2stroke or 4stroke
Also asked: “Why bigger flywheel on 4 stroke engine?”, “Flywheel in 2Stroke and 4 stroke ?”, “Flywheel difference between 2 and 4 stroke ?”
Answer
The four-stroke carries the bigger flywheel: half the power strokes per revolution means double the energy swing to smooth.
- Energy fluctuation per cycle sets flywheel size through mass moment of inertia times the speed-fluctuation coefficient.
- Four-stroke fires every second revolution, so each power pulse must carry the shaft twice as far.
- Bigger rim inertia holds speed fluctuation inside limits at constant-speed governor settings.
- Surveyors accept the rule as: fewer power strokes, bigger wheel for the same steadiness.
Surveyor follow-up: same power, two-stroke versus four-stroke — which governor works harder, and why?
Full theory: Indicator Diagrams, Power Balancing & Engine Performance -
6 Why time delay in co2 system....,co2 alarm is general alarm?... Difference between high pressure and low pressure....of co2
Answer
Delay buys escape, alarms warn before flooding, and pressure decides storage: 60–90 seconds, dedicated alarms, bottles versus tank.
- Time delay holds pilot gas 60–90 seconds so crew escapes after both cabinet valves move, and so the master valve opens before bottle pressure pins it.
- CO2 alarm is its own dedicated flooding alarm, never the general alarm — different sound, different action.
- High-pressure systems store liquid CO2 in bottle banks at about 56 bar; low-pressure stores refrigerated liquid in a bulk tank.
- Release proves by roar, cold bottles and manifold pressure — ventilate and seek shore advice before re-entry.
Surveyor follow-up: cabinet open with crew unaccounted — release or hold, and what do you do with the delay time?
Full theory: CO2 Fixed Fire-Fighting System on Ships -
7 Bilge oil separators control the discharge of oil overboard when bilges are being pumped out from the engine room, as required by Annex I
Answer
Bilge separators meter clean water overboard and stop dirty flow: 15 ppm proved, auto-stop armed, every drop logged.
- Gravity plus coalescing stages land effluent under 15 ppm before the monitor sees it.
- Past the rate or on monitor failure the discharge stops itself and the failure goes in the book.
- Manual operation allowed only logged with method — 100 ppm or 15 ppm plant — and positions.
- Surveyors read calibration, stop function and record entries before the pump handle.
Surveyor follow-up: monitor fails mid-discharge with clean effluent — keep pumping or stop, and which code?
Full theory: How Oily Water Separation Works — Gravity, Coalescence and Why Turbulence Ruins It -
8 Different alarms in engine room
Answer
Engine-room alarms guard fire, flood, oil and air: bilge, smoke, CO2, mist, levels, pressures and trips each own a bell.
- Bilge high-level, fire detection, CO2 release, oil-mist and scavenge-fire alarms cover the casualty set.
- Level alarms on tanks, crankcase and air boxes with pressure alarms on lube, cooling, fuel and air.
- Temperature alarms on bearings, exhaust, scavenge and coolers with trip backup behind each.
- Bridge and control-room repeats with first-out marking — the watch answers the first bell, not the loudest.
Surveyor follow-up: three alarms together — fire, bilge and low pressure — which one do you answer first?
Full theory: Engine Watchkeeping — Handover, Rounds & Work Safety -
9 Engine room crane electmagnetic brake releases how ?
Answer
The crane brake holds by spring and releases by magnet: power pulls the spring in to run, failure lets it grip the drum.
- Centrifugal shoes inside the drum sit applied by magnetic springs with no power on.
- Energising pulls the springs inward by electromagnetic effect, freeing the drum for normal travel.
- Power loss drops the springs back on — the loaded hook hangs, never falls.
- Emergency stop on the remote backs the brake with limit switches and overload trips around it.
Surveyor follow-up: brake slips with power healthy — springs, shoes or magnet, and what do you measure?
Full theory: Deck Cranes — Three Motions, Level Luffing and Safety Features -
10 Formed oil vapour, cargo residues and dust from engine room
Also asked: “• Formed oil vapour, cargo residues and dust from engine room”
Answer
Engine-room air carries oil vapour, cargo dust and hot spots toward explosion: ventilate, drain and watch the mist.
- Oil vapour from hot bearings and cargo residues settles toward the 2.5–5% lower-explosive band with dust adding fuel.
- Hot spots near 300–400 degrees past flash point light the mix — hand-feel doors, listen for knock, watch bearing temperatures.
- Ventilate crankcase and machinery air, drain separators and receivers, prove mist detectors per unit.
- Dense mist on the breather with rising temperatures means slow down and stop, never open hot.
Surveyor follow-up: breather smoking with one door hot — ventilate, open or stop, and in what order?
Full theory: Marine Turbochargers: Aerodynamics, Bearings, Washing & Surge Mitigation -
11 Loose pulley, flywheel, belt, belt guard, cooler, clamps or accessories Lack of oil in the crankcase Piston hitting the valve plate i.e reduced bumping clearance Compressor holding down bolts are loose Compress
Also asked: “ Loose pulley, flywheel, belt, belt guard, cooler, clamps or accessories Lack of oil in the crankcase Piston hitting the valve plate i.e reduced bumping clearance Compressor holding down bolts are loose Compressor foundation chocks have worn out”
Answer
Noisy compressors knock from loose iron, dry sumps and tight pistons: tighten, fill, shim and bolt down in that order.
- Loose pulleys, flywheels, belts, guards, coolers and clamps rattle first — tighten to torque with alignment proved.
- Low sump oil starves splash and pressure feed together; fill to marks with the grade aboard.
- Piston kissing the valve plate means lost bumping clearance — shim head gaskets and rod-foot packs back to band.
- Slack holding-down bolts and dead chocks let the whole set walk — tension long-sleeve bolts hydraulically.
Surveyor follow-up: knock easing with oil filled — belt, clearance or bolts, and what do you measure first?
Full theory: Maintenance and Troubleshooting — Overhauls, Tappet Clearance and Reading a Fault -
12 Describe, with the aid of sketches, a system of turbo-charging a two-stroke cycle main engine, State the routine attention, which should be given to the turbo-charger. Which parameters are to be recorded during watch kee
Also asked: “Describe, with the aid of sketches, a system of turbo-charging a two-stroke cycle main engine, State the routine attention, which should be given to the turbo-charger. Which parameters are to be recorded during watch keeping?”
Answer
Sketch Sulzer pulse charging at BDC: exhaust valve opens near 95° past TDC, gas pulses spin close-coupled turbochargers into scavenge trunks.
- Draw exhaust valve, manifold branches, turbine, blower, air cooler and scavenge trunk in gas order with sea cooling in-out and drains.
- Pulse pipes stay short and small-bored to the turbine so each cylinder’s blowdown hits the wheel sharp.
- Routine care runs washing air and gas sides, proving bearings, seals and drains with vibration watched.
- Log exhaust temperatures per unit, scavenge pressure and temperature, turbocharger rpm and vibration, cooler differentials and fuel index.
Surveyor follow-up: one unit hot with scavenge pressure steady and turbocharger rpm sagging — gas side, air side or fuel first?
Full theory: Marine Turbochargers: Aerodynamics, Bearings, Washing & Surge Mitigation -
13 What are the provisions for engine room under MARPOL 73/78 Annex 1 for large ocean going oil tanker
Answer
Annex I arms the engine room against oil: sludge tanks, separators, monitors and books sized to machinery and voyage.
- Sludge tanks past 400 gross tons take purifier residues and leakages that cannot go overboard, built for cleaning and discharge ashore.
- Separating and filtering plant with 15-ppm monitors and auto-stop guards every machinery-bilge discharge.
- Tanker cargo areas add monitoring-and-control with permanent records and 50-mile, en-route and rate limits.
- Prove by record books, monitor traces and reception receipts — sludge retained aboard beats sludge explained away.
Surveyor follow-up: sludge tank full with reception booked next port and bilges rising — retain, burn or discharge, and what paper covers it?
Full theory: MARPOL Annex I — Prevention of Pollution by Oil -
14 What is flywheel
Answer
The flywheel is the crankshaft’s energy bank aft: it stores surplus torque and pays it back through the dead spots.
- Absorbs extra energy when firing torque exceeds load demand and returns it when the load exceeds firing torque.
- Holds speed fluctuation inside load limits while the governor moves fuel to the new setting.
- Stores starting-system energy to carry the shaft through compression to first firing.
- More cylinders need less wheel — past about twelve the firing overlap smooths itself and the wheel shrinks or goes.
Surveyor follow-up: speed hunting with the governor proved steady and the wheel intact — load, fuel or firing balance first?
Full theory: The Engine Structure — Bedplate, Frame, Crankshaft and Main Bearings -
15 As a duty engineer, what would you check in the engine room crane, while the ship is leaving the port?
Also asked: “• As a duty engineer, what would you check in the engine room crane, while the ship is leaving the port?”
Answer
Check the crane before it leaves the ECR: the brake is the safety gear, and everything else is convenience.
- Check the electromagnetic brake — measure the magnet-to-armature gap at about 0.5 mm and adjust the braking nut to suit.
- After any overhaul, energise the magnetic coil alone to confirm it holds, since the brake releases on power and must be fail-safe.
- Check the hook throat opening and shape: more than 15% opening or more than 10 degrees of twist means replace the hook.
- Confirm limit switches on hoist, lower, slew and traverse, the mechanical stoppers, the overload trip, the rail guard and the safe working load marking.
Surveyor follow-up: crane brake gap 1.2 mm at sea with no load — adjust, replace the magnet or re-stroke the armature?
Full theory: Crane, Windlass & Deck Machinery — Brakes, Checks, Tests & Safeties -
16 Flywheel which is big 2 stroke or 4 stroke n y
Answer
The two-stroke: it swings far more cylinders, so it needs a much heavier flywheel to even out the torque pulses.
- A two-stroke fires every revolution of every cylinder, so each firing delivers a much larger share of the power stroke.
- The flywheel must store and return more energy between firings, and it is proportionately heavier for the same power.
- A four-stroke fires half as often, its torque pulses are more even, and the wheel can be far lighter for the same output.
- That is why auxiliary generators rarely need a large flywheel while a slow-speed main engine does.
Surveyor follow-up: auxiliary engine with a flywheel far larger than a comparable four-stroke — is it engine type, speed or duty?
Full theory: Two-Stroke Structure — Frame, Tie Rods, Liner, Piston & Crosshead -
17 How to identify an alarm in the engine room
Answer
Identify an alarm by sound first, then read the annunciator panel and trace the point to the actual gauge — never guess at the cause.
- The sound tells you the category: fire, gas or oil-mist is urgent; a single slow tone is usually a running alarm.
- Read the annunciator for the tag, then go to the actual gauge and read the real value against its limits.
- Check whether it is a condition or a defect: an alarm that repeats with a healthy gauge is usually a sensor or switch fault.
- Silence only to work the cause, and log the time, the reading, the action and the reset — an unlogged alarm is an unanswered one.
Surveyor follow-up: alarm repeating with every gauge normal — is it the sensor, the switch or the annunciator itself?
Full theory: Instruments & Safety Systems -
18 How to relese co2 when fire in engine room(if your 2 nd engineer is missing
Answer
You do not enter to release it: seal the space, run the delay, and operate the cabinet from the fire control station by the procedure.
- Account for every crew member first — a missing engineer is a reason to search, never a reason to open the cabinet blind.
- Close vents, doors and flaps, shut the fuel-line quick-closing valves, and start boundary cooling on the emergency fire pump.
- Operate the CO₂ system from the fire control station, not from inside the space, and let the time delay run.
- If a man is missing, the master assumes he is dead and the release proceeds — nobody enters a space to look for him.
Surveyor follow-up: second engineer unaccounted for at the moment of release — flood, search first, or who authorises it?
Full theory: CO2 Fixed Fire-Fighting System on Ships -
19 If there is a fire on deck and if fire main line is damaged then only by water how will you extinguish fire? ( only by water
Answer
With the main damaged, water comes from the emergency pump or portable monitors — and portable extinguishers cover what the hose cannot reach.
- Start the emergency fire pump to feed the intact part of the system and the fire main beyond the damaged section.
- Use portable monitors and the emergency fire main connection to lay water on the seat of the fire from a safe distance.
- Portable extinguishers of the right class — dry powder for oil and electrics, water or foam for solids — for the fringe.
- Boundary cooling and isolation continue throughout; a severed main is a lost tool, not a lost ship.
Surveyor follow-up: main ruptured at the manifold with the emergency pump already running for the boundary — what next?
Full theory: Ship Fire Main & Emergency Fire Pump System -
20 Scrubber tower alarm n trips
Answer
Inert gas trips on the scrubber: water level, deck seal, oxygen content, temperature and sea-water supply pressure.
- Trips include scrubber water high level and deck seal low water level, both of which flood or starve the tower.
- Emergency stop, power failure, and high oxygen content around 8% in the atmosphere all stop the system.
- High inert gas temperature and low pressure in the line after the blower show the plant is not making gas.
- Low sea-water supply pressure, around 0.7 bar to the scrubber tower and around 1.5 bar to the deck seal, trips on low water.
Surveyor follow-up: oxygen trip at 8% with scrubber water level normal and sea pressure proved — where is the air coming in?
Full theory: Deck Foam & Inert Gas (IG) Systems on Tankers -
21 The checks to be carried out in engine room during ILLC survey
Answer
The ILLC survey is measurement and proof: plate thickness, structure, tanks, safety systems and the certificates behind them.
- Shell plating, decks, bulkheads and structural members are gauged and inspected for wastage, deformation and coating breakdown.
- Tanks are examined for corrosion and the oil record book, the safety equipment and the statutory certificates are checked against the work done.
- Thickness measurements run before or with the close-up survey — each deck plate, three transverse sections, each bottom plate in the cargo area.
- Boilers, pressure vessels, electrical equipment and safety gear are examined under their own rules, and the findings are recorded with the margins allowed.
Surveyor follow-up: ILLC complete with no thickness measurements on file — which schedule was actually satisfied?
Full theory: Ship Classification, Surveys and Drydocking -
22 Type of sensors used in engine room
Answer
Engine room instruments are pressure, temperature, level and speed, with electrical or pneumatic outputs to the alarm system.
- Pressure and temperature sensors guard the lube, jacket and scavenging systems, with switches that alarm and trip.
- Level sensors watch the sump, the expansion tank and the oil systems — float, capacitance or ultrasonic types.
- Speed sensors feed the governor and the tachometer, and proximity probes give the crankshaft position for timing.
- Each has a spare and a calibration record, because a sensor proved only by the alarm is a sensor nobody has checked.
Surveyor follow-up: jacket temperature alarm proved by moving the sensor rather than the switch — what was actually tested?
Full theory: Instruments & Safety Systems -
23 What is the difference between co2 alarm and fire alarm and general alarm
Answer
Different alarms mean different things: CO₂ says gas is in the space, a fire alarm says a detector has seen fire, a general alarm says something has moved.
- A CO₂ alarm is sounded by the release cabinet, meaning the gas is about to be or has been discharged into a protected space.
- A fire alarm comes from a detector — heat, smoke or flame — or a manual call point, and says nothing about which agent will be used.
- A general alarm annunciates any abnormal condition: low oil pressure, high temperature, failed alarm or a tripped safety system.
- So the crew must know all three, because the first two may be followed by the third and by an evacuation.
Surveyor follow-up: a general alarm in the engine control room with a fire alarm panel quiet — which system is it?
Full theory: Instruments & Safety Systems -
24 funtcion of flywheel
Also asked: “Purpose of flywheel”
Answer
The flywheel is the crank’s energy bank: it stores surplus torque and pays it back through the dead spots.
- Absorbs energy when firing torque exceeds load demand and returns it when the load exceeds firing torque.
- Holds speed fluctuation within the limits the load requires while the governor moves fuel to the new setting.
- Stores energy from the starting system, carrying the shaft through compression to first firing.
- Increasing the number of cylinders reduces the irregularity, so past about twelve the firing overlap smooths itself.
Surveyor follow-up: engine hunting with the governor proved steady and the flywheel intact — load, fuel or firing balance first?
Full theory: Two-Stroke Structure — Frame, Tie Rods, Liner, Piston & Crosshead
Source: 123 written papers and surveyor oral banks, 24,613 entries, merged into 17,210 topics. Ticks are stored on this device only.