Safety update

November 1995 Fire protection in motor launches

This safety update is for owners and operators of motor launches. It is issued to raise awareness of the potential serious risk to safety on board motor launches. It provides safe practice tips for how to best reduce the risks involved and to alert people to the risk to safety associated with fire and/or explosion.


Maritime New Zealand wants to remind the owners and operators of motor launches of the dangers of fire and/or explosion in their vessels and the precautions that should be taken. If fire does occur, those onboard are often seriously injured and sometimes die.

The most common cause of fire aboard launches is the ignition of petrol vapour. Petrol fires are very difficult to extinguish.

Safe practice tips

Common sense strongly recommends the following safety precautions:

  • Do not use petrol for cleaning purposes. There are many other products available which are much safer and produce better results.
  • Carburettors on petrol engines should be fitted with wire-gauze covered drip trays, and flame traps should be fitted in the air intakes. Clean the drip trays before starting the engine.
  • Properly ventilated bilges and engine rooms are absolutely essential to the safe operation of any motor launch. Petrol, CNG, LPG and other gas vapours are heavier than air and will accumulate in the lowest parts of the launch. Vent tubes should extend right down into the bilges to ensure that any vapour collected there is removed.
  • Before starting up a petrol engine, open all doors, vents, etc., leading into or out of the engine compartment and allow the space to ventilate for at least 5 minutes.
  • Fit a cover over the batteries so that tools or other metal objects cannot fall on to the terminals and cause a spark.
  • Do not strike matches, smoke, or use kerosene or other open flame lamps inside the engine room.
  • Allow only safety matches to be used on board. Non-safety matches and cigarette lighters that can spark if dropped should be prohibited.
  • Inspect fuel tanks frequently and test them periodically (annually) to ensure that they do not leak. Where leaks have been caused by corrosion of the tanks, do not try to patch it. Replace the tank - it is cheaper than replacing the whole launch.
  • Filling pipes for fuel tanks should be led from near the bottom of the tank to the open deck outside cockpits and coamings so that any spillage of fuel will run overboard and not down to the bilges. Be sure the filling pipe covers are a good fit.
  • A vent pipe should be fitted to the top of each fuel tank that is the same size as the filling pipe. This should lead from the tank to the outside of the hull with the outlet covered with wire gauze.
  • Do not overfill fuel tanks. Leave some space for expansion of the fuel. • Take proper precautions when fuelling.
    • Except in emergencies all fuelling should be carried out in daylight. (b) All engines, motors, fans, etc., should be stopped.
    • Galley fires should be extinguished, and open lights put out before fuelling is started. Do not smoke, strike matches, or throw electric switches during fuelling.
    • When fuelling is complete close all filling pipes tightly and if any spillage has occurred wipe it up carefully. Allow sufficient time, at least 5 minutes, for proper ventilation after fuelling has been completed and before starting up the engines, lighting galley stoves, etc.
    • Fire extinguishers should be kept outside the engine room and in places where they can be reached from the open deck. They need to be accessible. C02, foam or dry-powder extinguishers are suitable for engine room fires. One 2-gallon foam extinguisher or one 10 lb. dry-powder extinguisher should be kept near the wheelhouse entrance or other suitable position. C02 or drypowder fire extinguishers are the most suitable for dealing with galley fires and one should be kept near the stove.
    • Make sure engine exhausts and uptakes are properly insulated and are not liable to scorch or set fire to nearby woodwork.
    • Petrol stoves are not recommended for use in boats. CNG, LPG or other gas stoves should be kept clean. Check to see that there are no leaks in the gas lines. The gas storage bottles should, if possible, be kept in a locker outside the galley or cabin in which the stove is located. Ensure that the stove is properly secured so that it will not overturn in rough weather. When not in use be sure gas stoves are properly switched off both at the stove and at the storage tank when the boat is unattended.
    • Check the electrical wiring periodically and replace any frayed or worn electric cables, broken plugs, lamp holders, etc.
    • Keep the boat clean. Remove inflammable rubbish such as dirty waste, rags, loose oil and grease etc.

Remember: A third of a litre of petrol which has vaporised in an enclosed space can cause an explosion equivalent to 2 kg of dynamite.

Observe the advice given in this notice and keep your boat out of the marine accident statistics.

Original source content - Boat Notice 021995: Fire protection in motor launches.

Email updates

Get an email notification when a safety update is available online.


Contact us for more help

If you have any questions about this safety update, please contact our Wellington office.


New Zealand (toll free):
0508 225 522

Call Maritime New Zealand now

Tell us what you need help with and remember to include your contact details (email address and phone numbers).