Inflatable Life Raft (SOLAS-A)

What defines this type

SOLAS-A denotes the equipment pack and construction standard, not the raft's size: it is the version required for ships on unrestricted or long international voyages, carrying the full LSA Code equipment scale rather than the reduced pack permitted on a SOLAS-B raft for shorter, better-supported routes. The defining engineering features are a self-righting canopy so the raft is usable whichever way it lands after inflation, and a hydrostatic release unit (HRU) on the painter line so the raft floats free and inflates automatically if the ship sinks before anyone can launch it by hand.

Main components

• Buoyancy tubes – two independent inflatable tube chambers, either can support the raft alone if the other is damaged.
• Floor – typically a double, inflatable insulated floor that keeps survivors off cold water beneath the raft.
• Canopy – self-erecting on inflation, shelters occupants and collects rainwater for drinking.
• Painter line and hydrostatic release unit – the line that triggers inflation on pulling, and the HRU that releases the raft automatically at a shallow depth if the ship goes down with the raft still in its cradle.
• Inflation system – a CO2 or CO2/N2 gas cylinder that inflates both buoyancy chambers and the canopy within roughly a minute of activation.
• Boarding ramp and righting strap – aids to board from the water and to right the raft if it inflates upside down.
• SOLAS-A equipment pack – rations, water, seasickness tablets, first aid, pyrotechnic flares, a signalling mirror and torch, fishing kit and repair materials to the scale set by the LSA Code.

Selection

The choice on a SOLAS-A raft is less about performance variants and more about matching stowage and capacity to the vessel:

• Capacity in persons, sized so the ship's total raft capacity covers the full complement with the required margin for a damaged raft.
• Container type: a rigid GRP canister for davit or float-free stowage on larger ships, versus a valise pack on smaller craft where a soft case is stowed in a dedicated locker.
• Float-free versus davit-launched arrangement, which decides whether an HRU is fitted at all and how the raft is cradled.

Regulations and class

SOLAS Chapter III sets out life-saving appliance carriage requirements, and the LSA Code fixes the SOLAS-A equipment scale and construction standard the raft and its pack must meet. Rafts require annual servicing at a manufacturer-approved service station, where the canister is opened, the raft inflated and inspected, the gas cylinder weighed, and the equipment pack checked against expiry dates. The hydrostatic release unit carries its own limited service life, commonly replaced on a fixed cycle rather than serviced, since its trigger mechanism cannot be reliably tested without destroying it. A raft or HRU running past its service or expiry date is a routine port state control detention item.