Part 5 - Outboard and portable combustion engines and portable fuel systems

Introduction to the subject matter covered by the checks in Part 5

This Part covers outboard motors, generators and other portable engines.

Carrying portable fuel tanks and transferring fuel can be hazardous if care is not taken - for example, petrol vapourises very readily during refuelling and can ignite very easily

Other fuels bring their own risks and they should be handled with equal care.

This chapter complements Chapter 2 (Fixed fuel systems and permanently installed engines) and reflects the particular hazards related to portable engines and their fuels on boats.

Risks associated with escaping fuels can be minimised by ensuring that fuel does not enter the interior of the boat, and that all components including portable fuel tanks and spare fuel containers, are suitable for the fuel used.

Keeping these in good condition and securely stowing the fuel containers will also reduce the risk of fuel spillage.

Notes on the qualities of fuels that have a bearing on the nature of the Requirements and the Examination Checking Procedures

Petrol is very volatile and quickly produces highly flammable vapours. Small spills of petrol create relatively large amounts of vapour.

The risks are also there when it is being transferred and especially when a tank is being filled and the vapour in the 'empty' tank is displaced by the liquid fuel.

Even if the concentration of vapour is too rich to burn immediately, it will dilute to flammable or explosive levels, even though when given enough ventilation, it may dissipate to a safe level eventually.

Petrol vapour is three to four times heavier than air. It will sink to the lowest level of its surroundings, accumulating at low level in places such as unventilated lockers and bilges or in enclosed spaces such as the
cabins and cockpits of boats.

The BSS requirements associated with boats fitted with, or carrying, outboard or portable engines, whether they are in use or not:

  • 13 All portable and outboard engines and portable fuel systems must be designed, installed and maintained in a way that minimises the risks of explosion or of fire starting and spreading.
  • 14 All spare petrol must be stored in a way that minimises the risk of fire and explosion.
  • 15 All portable and outboard engines with integral petrol or LPG tanks, and all portable petrol tanks, must be stored in a way that minimises the risks of fire or explosion when not in use.


The proposals

The revised version of the ECPs can be read from a pdf format file by clicking the link on the image on the right below.

The orginal version of the Checking procedures can be read by clicking on the link on the left-hand image. This will launch the chapter of the BSS Guide that also contains all the relevant guidance and descriptions which may offer a more whole perspective.

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ECP Cover 300x200

Click on this image to see original ECPs and notes  Click on this image to see Proposed revisions