GMA CoC EOOW cheat sheet

A UMS (unattended machinery space) watch alarm sequence normally escalates: dead-man alarm at the console first, then engineer's call alarm, then bridge alarm if unanswered within the preset delay.

Watch handover is complete only when the relieving engineer has physically verified running machinery parameters (pressures, temperatures, levels), not merely read the logbook.

The engine room watch must record: time, sea state, machinery running status, fuel/LO/water consumptions, and any abnormal conditions, at intervals not exceeding the period set by the Chief Engineer.

Standby engine status requires: main engine ready to manoeuvre, steering gear tested (including second pump / alternative power), and bridge informed of readiness.

Critical alarm setpoints must never be altered without Chief Engineer authorization; changes are logged with reason, date, and signature.

Bunkering operations require continuous watch at the manifold, agreed communication with the barge, scuppers plugged, and a pre-transfer checklist signed by both sides.

A dead-man alarm is normally reset every 3-15 minutes depending on the vessel's UMS classification; missing two consecutive resets escalates to the engineer's cabin alarm.

Before any machinery is opened for maintenance, isolation must include: energy source lockout/tagout, zero pressure verification, and draining/flushing of residual fluids.

Mean indicated pressure (mip) is calculated from the indicator diagram: mip = area of diagram / length of diagram, expressed in bar; it represents the average pressure acting on the piston during one cycle.

Indicated power for a single-acting engine: IHP = (mip × L × A × N × n) / 60, where L is stroke in m, A is piston area in m², N is rpm, n is number of cylinders (for two-stroke; for four-stroke divide by 2).

Brake power = indicated power × mechanical efficiency; specific fuel consumption (sfc) is normally quoted in g/kWh on a brake-power basis.

Turbocharger surging is typically caused by: fouled turbine/compressor, exhaust gas bypass valve fault, rapid load change, or air cooler restriction; corrective action is to reduce load and investigate.

For a steam turbine, the pressure-enthalpy (Mollier) diagram is used to determine work output; isentropic efficiency = actual enthalpy drop / isentropic enthalpy drop.

Gas turbine efficiency is improved by regeneration (exhaust heat recovery to combustion air) and intercooling; the Brayton cycle efficiency depends on pressure ratio.

Cylinder liner wear rate is normally monitored by measuring liner diameter at defined positions (top, middle, bottom) at each piston overhaul and comparing to the manufacturer's limits.

A two-stroke slow-speed diesel engine scavenges via uniflow ports and an exhaust valve; scavenge air pressure is a key indicator of turbocharger and scavenge port condition.

Fuel injection timing advanced too far causes high peak pressure and knocking; retarded timing causes high exhaust temperature and smoking.

Centrifugal pump affinity laws: flow ∝ speed, head ∝ speed², power ∝ speed³; these govern impeller trimming and VFD speed control.

NPSH available = (pressure at pump suction in head) − vapour pressure head of the liquid; cavitation occurs when NPSH available falls below NPSH required.

Positive displacement pumps (screw, gear, piston) are self-priming and deliver near-constant flow regardless of discharge pressure; a relief valve must be fitted on the discharge.

Reciprocating air compressor intercooling reduces air temperature and improves volumetric efficiency; the intercooler drain must be blown down regularly to prevent water carry-over.

A boiler safety valve must be set to lift at or below the design pressure; the boiler must never be fired with the safety valve gagged.

Steering gear testing before departure (SOLAS V/26) includes: full rudder movement from hard-over to hard-over, both pumps, both power supplies, and the emergency steering drill within 12 hours before departure.

HVAC relative humidity should be maintained typically at 40-60% for crew comfort and to prevent condensation on cold surfaces; chilled water supply temperature is normally 7-12°C.

Boiler water treatment controls: phosphate for scale prevention, hydrazine or sulphite for oxygen scavenging, and regular blowdown to control dissolved solids (TDS).

A centrifugal pump loses suction when the discharge valve is closed too long; running against a closed discharge causes overheating and possible seizure.

Ohm's law: V = I × R; power in a DC circuit: P = V × I = I²R = V²/R; for three-phase AC: P = √3 × V × I × cos φ.

A 4-20 mA current loop is standard for process instrumentation: 4 mA represents the zero/live-zero value, 20 mA the full-scale value; a 0 mA reading indicates a broken loop.

Insulation resistance is measured with a megohmmeter at 500 V DC for LV circuits; minimum acceptable values are typically ≥1 MΩ for motors and ≥1 MΩ for cables (per class rules).

A PID controller's proportional band (PB) is the % error that produces 100% output change; PB = 100 / gain. Integral action removes offset; derivative action anticipates change.

A PLC scan cycle consists of input scan, program execution, and output update; scan time must be shorter than the fastest process response required.

Battery charging: lead-acid cells are charged at 2.4 V/cell boost and 2.25 V/cell float at 25°C; temperature compensation is required.

A synchroscope shows the phase difference between the incoming generator and the busbar; the breaker is closed when the pointer is at 12 o'clock (in phase) and the frequency is slightly higher than the busbar.

A three-phase motor reverses direction by swapping any two of the three supply phases; a star-delta starter reduces starting current to about one-third of the direct-on-line value.

A short circuit in a circuit breaker is cleared by the instantaneous trip element; overload protection uses the thermal or long-time element.

A micrometer reading = main scale + thimble scale × least count; for a 0-25 mm metric micrometer, the least count is 0.01 mm.

Vernier caliper least count = smallest main scale division / number of vernier divisions; typically 0.02 mm.

Carbon steel contains up to about 2% carbon; above this it is cast iron. Increasing carbon raises hardness and tensile strength but reduces ductility and weldability.

Stainless steel grades 304 and 316 are austenitic; 316 contains molybdenum for improved chloride/pitting resistance in marine environments.

Sacrificial anodes (zinc or aluminium alloys) protect steel by cathodic protection; they must be replaced when about 50% consumed or per class rules.

A torque wrench must be calibrated at intervals (typically annually) and stored at its lowest setting to avoid spring fatigue.

Feeler gauges measure clearance; plastigauge measures bearing clearance by deformation of a plastic strip.

A bearing running temperature above about 70-80°C (depending on type) indicates inadequate lubrication, misalignment, or overload and must be investigated.

Welding symbols: fillet weld is shown as a triangle; a butt weld is shown by a V or U groove symbol; the arrow side is drawn below the reference line.

Transverse metacentric height GM = KM − KG; positive GM gives stable equilibrium; negative GM causes the vessel to list to one side and can lead to capsize.

Free surface effect reduces effective GM: FSC = (i × ρ) / (Δ), where i is the second moment of area of the free surface, ρ is liquid density, Δ is displacement.

Righting lever GZ = GM × sin θ (for small angles); the area under the GZ curve up to 30° must be at least 0.055 m·rad (IMO intact stability criterion).

Bulkhead watertight doors must be operable from both sides and the bridge; remote release is tested at intervals per SOLAS II-1.

Damage stability: flooding of a compartment reduces GM and increases draft; cross-flooding arrangements reduce list but increase trim.

A collision bulkhead must be located at least 0.05L (or 10 m, whichever is less) from the forward perpendicular, and not more than 0.08L (or 0.05L + 3 m).

The load line (Plimsoll) marks: S, W, T, F, and their tropical/freshwater variants; the summer freeboard is the reference.

A ship's stability booklet contains hydrostatic curves, KN or cross curves, and tank capacity tables; the engineer must know where it is kept and how to use it in an emergency.

STCW 2010 requires a minimum of 12 months seagoing service for certification as Officer in Charge of an Engineering Watch, plus approved education and training.

MARPOL Annex I covers oil pollution; Annex II noxious liquid substances; Annex III harmful substances in packaged form; Annex IV sewage; Annex V garbage; Annex VI air pollution.

MARPOL Annex VI sulphur limits: 0.50% m/m globally from 1 January 2020; 0.10% m/m in ECAs.

The Oil Record Book Part I is used for machinery space operations; entries must be signed by the officer in charge and each page by the Master.

ISM Code requires a Safety Management System (SMS) with documented procedures, a designated person ashore, and internal audits at intervals not exceeding 12 months.

SOLAS Chapter II-1 covers subdivision and stability; Chapter II-2 fire protection; Chapter III life-saving appliances; Chapter IV radio; Chapter V safety of navigation.

Class surveys include annual, intermediate, special (every 5 years), and continuous surveys; the Certificate of Class is issued on satisfactory completion of the special survey.

The Continuous Synopsis Record (CSR) records the ship's history of ownership, flag, and management; it must be kept on board and updated when changes occur.

Enclosed space entry requires: a permit, atmosphere testing (O₂ 20.9%, LEL <1%, H₂S <5 ppm, CO <5 ppm), continuous ventilation, a standby person at the entrance, and rescue equipment at the ready.

The fire triangle requires fuel, oxygen, and heat; removing any one extinguishes the fire. CO₂ displaces oxygen; foam blankets the fuel; dry powder interrupts the chain reaction.

The emergency fire pump must be capable of delivering at least two jets of water; it is located outside the machinery space and tested monthly.

The muster list must be displayed in each crew area and at the muster stations; it must be updated whenever there is a change in crew.

Abandon ship: the order is given by the Master only; the crew proceeds to the muster station with lifejackets, and the lifeboat is launched under the coxswain's direction.

Oil spill response: stop the source, contain with booms, use absorbents, and report to the port state and flag state; the SOPEP/SMPEP must be activated.

Personal protective equipment for engine room work includes: safety helmet, safety shoes, eye protection, hearing protection in high-noise areas, and gloves appropriate to the task.

First aid for electric shock: isolate the supply, then assess breathing and circulation; commence CPR if trained and the casualty is unresponsive and not breathing.

The engine room logbook records: date, time, position, course, speed, machinery parameters, fuel and water consumptions, and any incidents; it is a legal document and must be preserved.

The Chief Engineer's standing orders define watchkeeping arrangements, alarm responses, and reporting requirements; they must be read and signed by each engineer.

Effective communication uses closed-loop confirmation: the receiver repeats the message back to the sender to confirm understanding.

Fatigue management: STCW requires minimum rest periods of 10 hours in any 24-hour period and 77 hours in any 7-day period; rest records must be maintained.

The human element (HE) in accidents is addressed by the ISM Code and the STCW Convention; root cause analysis typically identifies organizational, supervisory, and individual factors.

Toolbox talks before a job brief the hazards, controls, and emergency arrangements; attendance is recorded.

Permit-to-work systems are required for hot work, enclosed space entry, working aloft, and electrical isolation; the permit is signed by the authorizing officer.

Near-miss reporting is a leading indicator of safety performance; reports are reviewed at safety committee meetings and used to update the SMS.