Maskinbefal cheat sheet

Two-stroke slow-speed diesel: uniflow scavenging via exhaust valve, crosshead design separates cylinder from crankcase; lube oil for cylinder liners is total-loss, fed by dedicated cylinder lubricators.

Four-stroke medium-speed diesel: trunk piston, common lube sump; indicated mean effective pressure typically 18–25 bar versus 18–21 bar for two-stroke; used with reduction gear where propeller rpm is low.

Propeller law: power varies with rpm cubed (P ∝ n³) and thrust with rpm squared; a fixed-pitch propeller's torque demand rises steeply, so engine overload shows as high exhaust temperature at low scavenge pressure.

Specific fuel consumption (SFCS) for large two-strokes is about 160–175 g/kWh at MCR; SFOC rises sharply below 50% load, so slow steaming is optimised by de-rating or part-load tuning.

Steam plant: superheated steam at 60–70 bar/510–520 °C; feedwater treatment controls dissolved oxygen (<0.02 mg/L) and conductivity to limit corrosion and scale.

Auxiliary systems: fuel treatment (settling tank, separator, filter) removes water and solids to <0.5% water before injection; purifier throughput is set by density and viscosity at separation temperature.

Boiler safety: safety valves set at or below design pressure, low-water-level cut-out tested regularly, and gauge glass blow-through confirms true water level before firing.

Cooling: central cooling system uses a single sea-water circuit with plate heat exchangers; jacket water is treated with corrosion inhibitor and kept at 70–85 °C to limit thermal stress.

Load line marks: freeboard measured from deck line to summer load line; Tropical (T) is higher than Summer (S), Winter (W) lower; the timber freeboard applies only when timber deck cargo rules are met.

Initial metacentric height GM = KM − KG; positive GM gives positive righting moment, and GZ = GM × sin θ for small angles (up to about 10–15°).

Angle of loll occurs when GM is negative; it is corrected by lowering G (ballast in double bottom) or reducing free surface, never by adding top weight.

Free surface effect reduces effective GM by FSC = (i × ρ)/Δ, where i is the second moment of area of the free surface; longitudinal bulkheads reduce i markedly.

Damage stability: the vessel must satisfy SOLAS probabilistic subdivision (A/R index); flooding of a compartment raises KG and may create a heel if the flooded space is asymmetric.

Ship types: bulk carrier single-deck with hopper sides and double bottom; tanker with longitudinal bulkheads and slop tanks; container ship with high GM and large windage area requiring careful berthing.

Shear force and bending moment: still-water plus wave-induced loads cause hogging (deck tension) and sagging (deck compression); load distribution must keep both within class limits.

Hull stresses: panting frames resist fluctuating pressure at the bow, and transverse strength is provided by floors, webs and decks; continuous longitudinal strength comes from the upper deck and inner bottom.

Planned maintenance system (PMS): jobs are scheduled by running hours or calendar interval; overdue items are recorded and reported to the technical manager, not silently deferred.

Crankcase inspection: check for oil mist, hot spots, bearing wear and loose parts; oil mist detector alarm requires stopping the engine and investigating before restart.

Cylinder liner wear: measured at top, middle and bottom of the liner with a dial gauge; maximum wear rate for a large two-stroke is typically 0.05–0.1 mm per 1,000 hours.

Exhaust valve and turbocharger fouling show as rising exhaust gas temperature and falling scavenge air pressure; water washing of the turbine and compressor restores efficiency.

Fuel injection troubleshooting: high exhaust temperature in one unit suggests faulty injector, delayed injection timing, or worn fuel pump; compare individual exhaust temperatures at the same load.

Vibration analysis and thermography are condition-monitoring tools; trending bearing temperatures and vibration velocity (ISO 10816 zones) detects misalignment before failure.

Starting-air system: minimum pressure typically 25–30 bar; interlocks prevent starting with turning gear engaged, and the air receiver must hold enough starts for the class requirement.

Spare parts and stores: critical spares are class-required and must be on board; consumption records support reordering and demonstrate maintenance history during surveys.

Three-phase AC: line voltage = √3 × phase voltage in star connection; line current equals phase current in star, while line current = √3 × phase current in delta.

Generator protection includes overcurrent, reverse power, under/over voltage and frequency; reverse power trip prevents a generator from motoring when its prime mover loses power.

Synchronisation conditions: equal voltage, frequency, phase sequence and phase angle; the synchroscope should be at the 12 o'clock position before closing the breaker.

Insulation resistance: measured with a 500 V DC megohmmeter; a reading below 1 MΩ on a 440 V system requires investigation, and readings are corrected to 40 °C for trending.

Earthing: the hull is the return path on an insulated-neutral system; earth fault detection monitors leakage and a second fault can cause a short circuit and trip.

Automation: PID control loop with proportional, integral and derivative action; integral action removes steady-state offset, derivative action responds to rate of change and amplifies noise.

Unmanned machinery space (UMS) requires alarms and safety systems tested before each unattended period; alarm limits and dead bands are recorded in the PMS.

Battery and UPS: lead-acid cells need ventilation because charging releases hydrogen; specific gravity around 1.28 indicates a fully charged cell at 25 °C.

Fire triangle: fuel, oxygen and heat; extinguishing removes one leg - cooling (water), smothering (CO₂/foam), or chemical inhibition (dry powder).

Fire classes: A solid, B flammable liquid, C gas, D metal, and electrical fires; water is prohibited on electrical and oil fires, CO₂ is suitable for machinery spaces when personnel are evacuated.

Fixed CO₂ system: release requires warning alarm, evacuation and head count; CO₂ concentration of about 30–35% by volume extinguishes a machinery-space fire by oxygen displacement.

Enclosed space entry: permit required, atmosphere tested for O₂ (20.9% normal, entry above 20%), hydrocarbons and toxic gas (H₂S below 5 ppm); a standby man is posted at the entrance.

Emergency drills: SOLAS requires abandon-ship and fire drills monthly; each crew member must participate in at least one abandon-ship drill and one fire drill per month.

Life-saving appliances: immersion suits and lifejackets inspected monthly; lifeboat engines run weekly and the boat launched and manoeuvred at least every three months.

Personal protective equipment: helmet, safety shoes, gloves and eye protection in the engine room; hearing protection where noise exceeds 85 dB(A).

Emergency generator: tested weekly under load, must start automatically on main power failure and supply emergency lighting, steering gear and radio within 45 seconds.

MARPOL Annex I (oil): any discharge of oil or oily mixture is prohibited except under specified conditions; machinery-space bilge water must pass through 15 ppm equipment with an alarm and automatic stopping device.

Oil Record Book Part I records all bilge transfers, sludge disposal and bunkering; entries are signed by the person in charge and the master, and are retained for three years.

Annex II (noxious liquid substances): discharge depends on category X, Y, Z or OS; category X may not be discharged into the sea, and prewash is required before ballasting.

Annex IV (sewage): discharge of comminuted and disinfected sewage is allowed beyond 3 nautical miles from land, untreated sewage beyond 12 nm, and only at moderate speed.

Annex V (garbage): plastics may never be discharged; food waste may be discharged beyond 3 nm (comminuted) or 12 nm (not comminuted); garbage record book kept for two years.

Annex VI (air): sulphur content of fuel oil limited to 0.50% globally and 0.10% in ECAs; ships must hold a Bunker Delivery Note and a sample for 12 months.

Ballast water management: exchange must achieve 95% volumetric exchange or pump through three times tank volume; D-2 treatment standard applies to new ships and after the compliance date.

Environmental emergencies: SOPEP contains contact details, response equipment inventory and reporting procedures; pollution incidents are reported to the nearest coastal state without delay.

STCW 2010 Manila Amendments: minimum rest 10 hours in any 24-hour period and 77 hours in any 7-day period; rest may be split into at most two periods, one of at least 6 hours.

Watchkeeping: the officer of the watch (OOW) is responsible for the safe navigational and engineering watch; handover includes machinery status, alarms, ongoing work and standing orders.

SOLAS Chapter V: continuous watch by qualified personnel; the master's night orders and standing orders must be read and signed by watch officers.

ISM Code: safety management system with documented procedures, designated person ashore, and internal audits; non-conformities are recorded and closed out with root-cause analysis.

MARPOL and load line certificates have a maximum validity of five years, subject to annual and intermediate surveys; the class certificate confirms hull and machinery compliance.

Muster list and emergency organisation: every crew member has a designated station and duty; the list is posted in accommodation and updated when crew changes.

Fatigue management: records of hours of rest are maintained and signed; the master may require a watchkeeper to rest if fitness for duty is compromised.

Pollution reporting and casualty investigation: the flag state investigates marine casualties; near misses are reported internally to prevent recurrence.

Safety committee meets at least monthly; minutes record hazards, near misses and corrective actions, and are reviewed by the master and the designated person ashore.

Permit-to-work systems cover hot work, enclosed space entry, working aloft and electrical isolation; the permit is signed by the responsible officer and valid only for the stated task and period.

Toolbox talk before a non-routine job identifies hazards, controls, PPE and the stop-work authority of every participant.

Human error is reduced by closed-loop communication: the sender states the order, the receiver repeats it back, and the sender confirms.

Just culture distinguishes human error from at-risk behaviour and reckless violation; reporting near misses without blame increases the reporting rate and safety performance.

Fatigue, complacency and inadequate situation awareness are the dominant human-factor contributors to machinery-space incidents; watch handover is a high-risk moment.

Leadership: brief the team, set clear expectations, verify understanding, and debrief after drills and incidents to capture lessons learned.

Records: official log book, oil record book, garbage record book, training records and rest-hour records are retained per flag-state and company requirements.