LSA Chapter 5: Lifeboats — Types, Engine, Davit & Drills

1. Types, Approval & Strength Regulation

When the surveyor asks "what are the types of lifeboat?", name all three families in one line — open (oars plus engine), enclosed (roofed, seated) and freefall (slid from aft) — then give the regulation.

• Open lifeboat: as the name suggests it has no roof and is normally propelled by manual power using hand-propelled oars; a compression-ignition engine may also be fitted. Open boats are becoming obsolete under stringent safety norms but survive on older ships — they give little help in rain or bad weather and the possibility of water ingress is highest.
• Closed lifeboat: the most popular type — enclosed, saving the crew from seawater, strong wind and rough weather, with higher watertight integrity and the ability to get upright on its own if toppled by waves. Further classified as partially enclosed (rigid permanent canopy at bow and stern with foldable canvas shelter in midships, fitted primarily on passenger ships for rapid embarkation) and fully or totally enclosed (inherently self-righting when fully loaded and battened down; tanker versions carry compressed air cylinders giving at least 10 minutes of positive pressure and external water-spray deluge fire protection).
• Freefall lifeboat: similar to an enclosed boat but launched entirely differently — aerodynamic so it penetrates the water without damaging the body. Located at the aft of the ship, giving maximum clear area for free fall: the stern ramp skid launch converts gravity into forward hydrodynamic momentum, giving instant positive headway to clear the vessel even against 10° trim and 20° list.

Approval certificate — four entries

• Each lifeboat is fitted with a certificate of approval endorsed by the Administration containing at least: manufacturer name and address; lifeboat model and serial number; month and year of manufacture; number of persons approved to carry.

Strength and sizing rules to quote

• Of sufficient strength to safely launch when fully loaded with full complement of persons and equipment.
• Capable of being launched and towed when the ship is making headway at 5 knots in calm water.
• Except freefall boats, each falls-launched boat must withstand, when loaded with full complement and equipment with applicable skates or fenders in position, a lateral impact against the ship side at at least 3.5 m/s and also a drop into water from at least 3 m.
• Maximum persons: no lifeboat carries more than 150 persons.
• Size, number and capacity for a merchant vessel are decided by the type of ship and number of crew; minimum two lifeboats provided, one on each side (port and starboard).
• Ships of 20,000 GT and above must be capable of launching when heading at 5 knots.
• The ship must carry one rescue boat — one lifeboat may be designated as the rescue boat if more than one lifeboat is present.
• Gravity davits must hold and slide the boat down even when heeled 15 degrees either side; ropes holding the boat in its cradle are called gripes.
• The wires that lift or lower the boat are the falls: descent speed not more than 36 m/min, controlled by centrifugal brakes.
• Hoisting speed not less than 0.3 m/s with the boat loaded to full capacity.
• The lifeboat must be painted in international bright orange with the ship name painted on it.

Number chain for this section

150 persons maximum, 5 knots launch-and-tow and 5 knots headway launch at 20,000 GT, falls impact at 3.5 m/s with 3 m drop, davit heel 15 degrees, descent capped at 36 m/min and hoist at 0.3 m/s.

2. Engine, Fuel System & Release Hooks

For "tell me about the lifeboat engine", build the answer from fuel to propeller: the engine gives 6 knots for 24 hours, it must tow a 25-person raft at 2 knots, and the hook follows the on-load and no-load release rules.

• Type: powered by a compression-ignition engine; no engine may be used if its fuel has a flash point of 43 °C or less.
• Cycle and start: either two-stroke or four-stroke, started either by hand or by power.
• Power starting uses accumulator batteries or hydraulics, with two independent rechargeable energy sources normally provided.
• Any starting method must start the engine at 15 °C ambient within 2 minutes of commencing the starting procedure.
• Flooded running: capable of operating with the boat flooded up to the waterline of the crankshaft.
• Gearbox: power transmitted through a gearbox capable of disengaging the engine and engaging ahead or astern.
• Exhaust: pipe arranged to prevent water entering the engine during normal operation.
• Cold start: starting aids fitted as necessary to start at −15 °C within 2 minutes.
• Speed and endurance: speed at least 6 knots with a full complement of persons and equipment; fuel capacity sufficient to run at 6 knots for not less than 24 hours.
• Towing capacity: sufficient to tow a 25-person life raft loaded with its full complement at not less than 2 knots.

Lifeboat release hooks: on-load vs off-load & hydrostatic interlocks

Lifeboat release mechanisms are one of the most critical safety systems audited during Flag, Class, and PSC inspections. Accidental releases during drills historically caused severe fatalities, prompting comprehensive IMO amendments (Res. MSC.320(89) / MSC.1/Circ.1392) governing hook stability and interlocks.

Step-by-step lifeboat recovery & hook reset sequence

1. Waterborne State: Lifeboat is floating safely in water; the hydrostatic unit is in the open position (yellow indicator in the green zone).
2. Hook Reset to Closed Position: Crew members at forward and aft stations physically reset the hooks back into their fully closed, upright positions.
3. Release Handle to Original Position: Bring the central releasing lever/handle back to its neutral/locked home position and insert the mechanical safety locking pin.
4. Visual Pin Verification: Inspect both forward and aft hooks thoroughly. Verify that the securing pins (cams) are in 100% full contact with the hook's heel, preventing accidental unhooking.
5. Indicator Confirmation: Confirm that the central operating station indicator has returned to normal green alignment.
6. Attach Fall Links & Hoist Clear of Water: Connect the suspension ring links into the hooks. Lift the lifeboat just slightly above the sea surface (0.5 m) and hold.
7. Automatic Locking Check: Verify that the hydrostatic interlock bar has dropped back into the locked position (indicator shifting to RED) now that water pressure has dropped to zero.
8. Full Hoist & Davit Limit Switch: Hoist the boat until the davit arms come fully upright against the stops; verify the winch limit switch trips power to the motor to prevent wire parting.
9. Manual Final Stowing: Complete the final stowage manually with the hand crank handle. Engage cradle stoppers (harbour safety pins), connect automatic painter trigger lines, and secure over-lashings (gripes).

Fall preventer devices (FPDs) — SOLAS MSC.1/Circ.1327 / 1392

• Mandatory Safety Measure: To prevent fatal unintended releases during drills or maintenance, IMO introduced requirements for Fall Preventer Devices (FPDs) on all hook systems not yet compliant with new MSC.320(89) criteria.
• Types of FPDs: Heavy-duty synthetic slings (strops) or high-tensile locking pins passing directly through the hook cheeks beneath the fall ring.
• Operating Rule: FPDs must be securely fitted before any person enters a suspended lifeboat for testing or lowering. They are only removed just before the boat becomes waterborne, and reattached immediately upon recovery before hoisting out of the water.

Four instruments the surveyor points at

The inclinometer reads the angle of heel, the chronometer gives universal (GMT) time, the anemometer gives wind velocity, and the barometer gives atmospheric pressure.

Tanker lifeboats with fire-protection and self-contained air

• Fire-protected lifeboats: when waterborne, capable of protecting occupants through a continuous oil fire envelope for not less than 8 minutes.
• Water-spray system: engine-driven seawater pump draws from beneath the boat and sprays water over the entire exterior canopy through a piping manifold.
• Self-contained air system: bank of compressed air bottles supplies breathing air for the full complement and engine combustion air for not less than 10 minutes, maintaining positive pressure inside the cabin to prevent ingress of smoke and toxic gases.

3. Lifeboat Equipment (30 Items) & Markings

A surveyor asking "what is inside the lifeboat?" expects the 30 SOLAS inventory items structured logically:

Statutory lifeboat markings (8 items)

• 1 — Ship name: painted in block Roman letters on both bows.
• 2 — Port of registry: marked clearly on both bows.
• 3 — Lifeboat number: odd numbers on starboard, even numbers on port.
• 4 — IMO ship identification number: clearly marked.
• 5 — Call sign: ship radio call sign.
• 6 — Principal dimensions: length, breadth, and depth.
• 7 — Carrying capacity: number of persons approved.
• 8 — Retro-reflective tape: fitted on hull and canopy for radar and searchlight location.

Rescue boat drill — seven numbers

Rigid or inflatable, 3.8 m to 8.5 m long: 6 knots for 4 hours manoeuvring; 5 seated persons + 1 lying on a stretcher; inboard or outboard engine; recovery within 5 minutes with full complement; launchable at 10° trim and 20° list. Stowage: 1 each side on ships ≥ 500 GT, 1 boat on ships < 500 GT (passenger ships ≥ 500 GT carry at least 1 per side); a lifeboat may count as the rescue boat if launching and recovery arrangements comply.

4. Davit, Maintenance, No-Start Checks & Lowering Drill

For "how does the davit work?", describe the gravity system with its numbers: it lowers at 36 m per minute, it hoists at 0.3 m per second, and it is held by the dead-man grip.

• Gravity davits swing out and lower by the boat's own weight, effective at 15 degrees heel either side with gripes securing the boat in the stowed position.
• Descent speed: not more than 36 m per minute, governed by a centrifugal brake.
• Hoisting speed: not less than 0.3 m per second on recovery with the boat fully loaded.

Lowering drill — the full deck sequence

1. Pre-lowering rigging and painter: one crew member enters the boat, screws in the brass bottom drain plug and passes the end of the toggle painter forward to a strong deck cleat, making it fast. Check the overside is completely clear of garbage chutes, ballast overboard valves and flotsam.
2. Clear the boat and the ship side: check all lifelines and falls are clear of the boat, and make sure the ship's side is free of everything — no water or garbage outlet discharging.
3. Cast off gripes and harbour pin: release the forward and aft lashing gripes from the davit arms, rig the tricing pendants and bowsing tackles, and remove the davit harbour safety locking pin.
4. Swing out to the embarkation deck: one person lifts the dead-man handle slowly, releasing the brake; the boat with its cradle slides downward to the embarkation deck. Secure the bowsing tackles taut against the ship's side, pull the tricing pendant to bring the boat alongside, and board the complement quickly, fastening the 4-point harnesses.
5. Lower and hook release: remove the tricing pendant so the whole load comes on the falls, then lower further with the dead-man handle — from inside the boat, or from the deck winch, with the centrifugal brake regulating descent to 36 m per minute or less. The dead-man handle is nothing but a simple handle operated by only one person from inside; as soon as the boat comes to about 1 m above the seawater the handle can be released. At that height actuate the on-load release handle, or allow the hydrostatic off-load release on floating, cast off the toggle painter and steer clear at 6 knots.

Lowering checks as the engineer

• Battery properly charged.
• Rudder turning both port and starboard.
• Fuel tank, fuel pipe and lube-oil level.
• Air bottle pressure.
• Engine running in both directions — ahead and astern.
• Electrical connections.
• Bilge pump and plug condition.
• All tools in the toolbox.
• Shaft sealing.

Davit safety devices — six to name

• 1 — Dead-man (dead hook) handle — lowering stops the instant the operator releases grip; the boat is lowered only while one person holds it.
• 2 — Harbour pin — locks the davit arm in harbour/stowed position.
• 3 — Winch upper limit switch — cuts hoisting before the blocks foul the davit head; cleaned and checked weekly.
• 4 — Drum brake — holds the falls on the winch drum under load.
• 5 — Release gear hook ring (release hooks) — post-2014 simultaneous-release hooks with locks and interlocks.
• 6 — Winch brake counterweight — assists controlled lowering and brake release.

Off-load versus on-load release

• Off-load: releases the boat after the load transfers to the water — when the boat touches the surface the load on the falls and hooks releases and the hooks detach; any crew member can remove a stuck hook. Often manually disengaged on malfunction — but in fire it is dangerous to go out and release the hook.
• On-load: releases the boat from the wire with the boat still above water and all crew inside — load still on the falls. Normally about 1 m height is kept so the fall is smooth without damaging the boat or harming the crew. A lever inside the boat operates it — safe without going outside when there is fire on board.

Maintenance and weekly checks

• Engine trial weekly — propulsion checked both ahead and astern.
• Battery checks by the electrical officer, renewed about every 2 years.
• Mechanical linkages and electrical launching-gear equipment checked including lubrication; cleaning of the davit limit switch.
• Weekly the boat is lowered to the embarkation ladder and all davit mechanism inspected and checked.
• Winch hand-operated brake gets static and dynamic tests.
• The boat is launched once in 3 months and taken for a round to prove proper functioning.
• Tanker air system: the O2 cylinders are provided so oxygen is released when the boat passes through fire.

Lifeboat engine not starting — 12 checks

• Empty fuel tank.
• Incorrectly attached fuel supply hose.
• Damaged fuel supply hose.
• Defective fuel pump.
• Contaminated fuel.
• Improper starting procedure.
• Faulty, spoiled or incorrectly positioned spark plug(s).
• Improper maintenance.
• Emergency shut-off de-activated.
• Undercharged starter battery.
• Loose electrical connections.
• Bad ignition coil and defective starter motor.

Davit safeties & engine no-start rapid checks

Six davit safeties: dead-man brake handle, harbour safety pin, upper limit cut-off switch, winch drum brake, automatic resetting hook ring and winch counterweight.

Common engine no-start faults: fuel valve shut or empty tank, air lock in the fuel line or contaminated fuel, dead starter battery below 24V, emergency shut-off tripped, loose electrical terminals, and a defective solenoid or starter motor.

Dead-man handle use

• Hold the handle to lower; release to stop instantly — never lash or wedge it open.
• Lower in short controlled stages, watching both falls; stop on any uneven fall, list change, or overside obstruction.

Drill-week answer

"When did you last lower and launch?" — lower to embarkation weekly, launch with round turn 3-monthly, engine ahead and astern weekly, battery about 2-yearly, davit descent capped at 36 m/min and hoist at 0.3 m/s.

5. Freefall Rules & Oral-Exam Rapid Fire

Freefall boats — capacity, seating, clearance and strength

Freefall boats must meet totally-enclosed requirements plus the freefall rules below — the surveyor's favourite closing station. The boat is painted in international bright orange with high-intensity retro-reflective tape, and the statutory markings are cut in clear Roman capital block letters on the bows.

• Capacity: the number of persons that can be provided with a seat without interfering with propulsion or equipment operation.
• Seat dimensions: width at least 430 mm; free clearance in front of the backrest at least 635 mm; backrest extending at least 1000 mm above the seat pan. Every occupant is given an aft-facing contoured seat fitted with a 4-point shock-absorbing safety harness and head support.
• Headway and clearing: must make positive headway immediately after water entry and not contact the ship after freefall launching against a trim up to 10° and a list up to 20° either way from the certification height when fully equipped and loaded with: full complement; occupants giving the most forward centre of gravity; occupants giving the most aft centre of gravity; operating crew only.
• Strength: must withstand, loaded with full complement and equipment, a freefall launch from at least 1.3 times the freefall certification height.

Release system — five rules

• Two independent activation systems, operable only from inside the boat and marked in a contrasting colour.
• Must release under any loading from no load up to at least 200% of normal load of the fully equipped boat with its approved persons.
• Adequately protected against accidental or premature use.
• Designed to test the release system without launching the boat, using a secondary hydraulic test valve.
• Factor of safety 6 on ultimate material strength.

Freefall certificate extras — three entries

• Beyond the fully-enclosed certificate, the approval must also state the freefall certification height, the required launching ramp length, and the launching ramp angle for that height.

Oral-exam rapid fire

• "Engine?" — compression ignition, flash above 43 °C, 2/4-stroke, hand or power, 15 °C in 2 min, crankshaft-waterline flooding, 5 min cold, 6 kn / 24 h, tows biggest raft 2 kn / 25 persons.
• "Hooks?" — post-2014: no load on release gear, non-opening locks, hydrostatic auto-reset.
• "No start?" — run the 12-check list from empty tank to starter motor.
• "Markings?" — Roman alphabet: ship name, maker + trademark, serial, port, IMO, call sign, capacity, dimensions — orange hull.
• "Drill weeks?" — weekly engine + embarkation lowering, 3-monthly launch with round turn.

Closing line for the examiner

Quote the chain: fully loaded launch → 5 knot tow → 3.5 m/s + 3 m falls test → 43 °C fuel → 6 knots / 24 hours → 36 m/min down → 0.3 m/s up → 1 m release → 3-monthly round turn — every number in one breath.