Fire extinguishers

Guidance on fire extinguishers to have on board a boat, yacht or motorboat

In the heat of the moment, will yours fit?

I was on board a brand new 40 footer destined for use by an RYA Training Centre for cruising courses; this was its first inspection.

The yacht was up to spec with lots of expensive and shiny new safety equipment and signage, making her look like a floating Health and Safety advert.

‘I doubt it’ll fit’, I said. ‘Do you mind if we try?’

We were discussing whether the engine fire extinguisher would actually fire through the key-hole in the engine compartment fascia.

Unfortunately, the extinguisher did not have a nozzle or tubing to feed through the key-hole; because of its design it could not be positioned to effectively fire through the hole.

It was agreed the extinguisher had to be exchanged.

On examining the engine compartment the problem was found to be more fundamental; the hole was in the wrong place. The key-hole in the fascia was positioned so that any extinguisher fired through the hole would simply hit the engine casing, where there would be little chance of fire.

The owner was aghast; the solution was to drill another key-hole in a position where the fire extinguisher had a chance of reaching the area’s most at risk fire.

Causes of engine fire

Common causes of engine fires are fuel and oils spraying onto a hot surface such as; turbo chargers, exhausts, and those made hot by malfunction, such as a pump. The other culprits are electrical faults; alternators and starter motors generate or use huge amounts of electricity.

    Extinguishers used to fight engine fires are either:
  • Inside the compartment and operate automatically at a certain temperature, or sound an alarm so that a manual trigger can be operated on deck.
  • Alternatively, they are outside the compartment and fired through a peep-hole in the fascia.

Types of extinguisher

    There are three common types of extinguisher fitted to leisure boats:
  1. Dry powder extinguishers which smother and create a chemical reaction with the fire. They can be fitted inside the compartment and operate automatically or fired through a key-hole.
  2. Halocarbons such as FE36 and FM 200, change the oxygen content in the air starving the fire of oxygen and are always fitted inside the engine bay.
  3. Pyrogen aerosols propel potassium radicals at the fire. These attach themselves to the flame reaction, extinguishing the fire chemically and are always fitted inside the engine bay.

What to do in the event of an engine fire:

  1. Do not to open the engine compartment and feed it with more air.
  2. Turn off the possible causes: diesel fuel, batteries.
  3. Close the engine seacock to prevent the inlet pipe burning through, sinking the boat.
  4. Alert everyone and get them on deck with lifejackets readying the liferaft but not inflating it.
  5. Smoke and heat is the immediate problem, so act fast and investigate early.
  6. Fight the fire with a clear route of escape.
  7. Crouch down low to escape heat and smoke.
  8. Ensure the fire is completely extinguished as embers remain hot for long periods. If opening the engine compartment do so after it has had chance to cool and have an extinguisher ready.

Written by: Simon Jinks – SeaRegs – RYA Yachtmaster™ Examiner and Marine Journalist