Murmester cheat sheet

Length overall (LOA) is measured from the foremost point of the hull to the aftermost point, excluding bowsprits and overhanging fittings; length between perpendiculars (LBP) is measured between fore and aft perpendiculars, with the aft perpendicular normally at the rudder stock.

Length on the waterline (LWL) is taken at the design waterline; register length and rule length may differ from LOA, so always state which length basis a certificate uses.

Beam is maximum breadth moulded for structural purposes and extreme breadth over plating for tonnage and berthing; depth is measured at amidships from keel top or moulded baseline to freeboard deck.

Displacement is the weight of water displaced at a given draught; deadweight is displacement minus lightship and covers cargo, fuel, water, stores, and crew effects.

Gross and net tonnage are dimensionless volumes under the 1969 Tonnage Convention (gross = K1 × V), not weights; they are used for fees and manning thresholds, never for stability calculations.

Classification societies assign class notations such as hull, machinery, ice class, and service restriction; class is a voluntary technical standard unless a flag State delegates statutory work to it.

Operational categories follow flag rules: unlimited, near-coastal, sheltered waters, and harbour limits; each category fixes permitted significant wave height, distance from safe haven, and required equipment.

Passenger ship means a ship carrying more than 12 passengers; cargo ship covers all other mechanical vessels, while special-purpose ships (tugs, dredgers, research) carry their own service notations.

SOLAS Chapter I sets the applicability: ships on international voyages, with chapter-specific thresholds (for example, Chapter IV radio applies from 300 gross tonnage on international voyages).

MARPOL has six technical annexes; Annex I (oil) and Annex IV (sewage) apply by tonnage and voyage type, while Annex VI (air pollution) applies to all ships above 400 gross tonnage.

Load line rules derive from the 1966 Load Line Convention as amended by the 1988 Protocol; the freeboard deck and load line mark positions are fixed by that instrument.

ISM Code applies to passenger ships and cargo ships of 500 gross tonnage and above on international voyages; the DOC is issued to the company and the SMC to the ship.

STCW sets minimum rest hours: at least 10 hours in any 24-hour period and 77 hours in any 7-day period, with rest split into no more than two periods.

Flag State implements conventions through national law; Port State control inspects against the same instruments under regional memoranda of understanding and may detain for detainable deficiencies.

Certificates have fixed maximum validity: Safety Construction, Safety Equipment, and Safety Radio certificates are normally 5 years, subject to annual and intermediate surveys.

The ISPS Code applies to passenger ships, cargo ships of 500 gross tonnage and above, and port facilities; each ship holds an International Ship Security Certificate valid up to 5 years.

Freeboard is the distance from the freeboard deck to the assigned load line; minimum freeboard increases with the tabular freeboard for length plus corrections for block coefficient, depth, superstructures, and sheer.

Load line marks: the summer mark sits at the assigned freeboard; tropical adds 1/48 of the summer draught, winter subtracts the same amount, and the fresh water allowance equals displacement divided by 4 × tonnes per centimetre immersion.

Initial transverse metacentric height GM = KM − KG; positive GM gives a righting moment, and the righting lever GZ = GM × sin θ for small angles only.

The intact stability criteria include an area under the GZ curve of at least 0.055 metre-radians to 30 degrees and 0.09 metre-radians to 40 degrees, and a maximum GZ at 30 degrees or more.

Damage stability is assessed by the probabilistic method (SOLAS Chapter II-1 subdivision index A ≥ R) for most cargo ships, with deterministic rules for specified ship types.

Watertight subdivision uses bulkhead decks and collision bulkheads; the collision bulkhead position is bounded between 0.05L and 0.08L from the forward perpendicular, or 0.05L plus 3 metres.

Longitudinal strength depends on section modulus and moment of inertia amidships; loading instruments check still-water shear force and bending moment against permitted harbour and seagoing values.

A ship's stability booklet and loading manual are approved documents; any change to lightweight or KG requires re-issuance of the inclining experiment report or deadweight survey.

Essential services must have redundant supplies; SOLAS requires at least two independent power sources, one being an emergency source located above the bulkhead deck outside the main machinery space.

The emergency generator must start automatically and take load within 45 seconds of main power failure, supplying emergency lighting, steering, radio, and fire pumps for the required period.

Insulation resistance readings are taken with the system isolated; a common bench mark is 1 megohm minimum for the installation, but class rules specify the acceptance value.

Propulsion arrangements include direct-drive low-speed diesel, geared medium-speed diesel, diesel-electric, and gas turbine; each has distinct fuel and maintenance profiles.

Steering gear must be capable of moving the rudder from 35 degrees on one side to 30 degrees on the other in not more than 28 seconds at rated speed.

Main and auxiliary machinery alarms and safety trips are type-tested; unattended machinery space (UMS) notation requires periodic inspection and alarm testing.

Fuel oil systems require quick-closing valves, high-temperature and low-pressure alarms, and a means to prevent overpressure; MARPOL Annex VI limits sulphur in fuel to 0.50 percent globally and 0.10 percent in emission control areas.

Electrical distribution uses main switchboard, emergency switchboard, and distribution boards; protective discrimination must ensure a fault trips only the affected circuit.

Lifeboat capacity and number depend on the ship type and the number of persons on board; cargo ships normally carry lifeboats or free-fall boats totalling 100 percent of persons, plus a rescue boat.

Lifebuoys, lifejackets, and immersion suits are specified by LSA Code; immersion suits are required where the ship operates in cold water, and lifejackets must include child sizes on passenger ships.

Fire detection and alarm systems must cover accommodation, service, and machinery spaces; fixed fire-extinguishing systems include CO2, foam, and water mist, each with distinct release and warning requirements.

Fire control plan must be permanently exhibited and duplicated in a marked container outside the deckhouse for shore firefighting use.

Fire drills and abandon-ship drills are conducted at intervals not exceeding one month; each crew member must participate in at least one abandon-ship drill every month.

Personal survival techniques, firefighting, and medical first aid are STCW basic training requirements; certificates of proficiency are separate from the Certificate of Competency.

Firemain pressure and hydrant spacing are fixed by SOLAS; the required number of fire pumps and their capacity scale with ship size and passenger numbers.

Emergency lighting and low-location lighting are required in escape routes; escape route marking and muster station identification are checked during surveys.

Initial survey precedes certificate issue; annual surveys fall within a window of three months before to three months after the anniversary date, and intermediate surveys replace one annual survey.

Renewal survey is carried out within three months before the certificate expiry; if completed early, the new certificate runs from the completion date, not the old expiry.

The Harmonized System of Survey and Certification aligns survey dates across SOLAS, MARPOL, and load line certificates; extension of certificate validity is limited to a maximum of three months in defined cases.

Classification surveys include annual, intermediate, special (five-yearly), and continuous survey cycles; the special survey includes thickness measurement and tank testing.

Port State control uses a targeting regime based on flag performance, company performance, and prior detentions; a detention triggers a follow-up verification inspection.

Deficiency codes are recorded against the ship; detainable deficiencies include inoperative fire pumps, missing charts, and lifeboat launching gear failures.

The Continuous Synopsis Record records the ship's ownership, flag, and management history; it must be updated within three months of any change and kept on board.

Documentation to be verified includes the Safety Management Certificate, Document of Compliance, International Oil Pollution Prevention Certificate, and the ship's certificates of class.