Paragraph 3

in the case of a motor vehicle so constructed that it is fitted with a crane, dynamo, plant or other special appliance or apparatus which is a permanent or essentially permanent fixture, the appliance or apparatus is not to be deemed to constitute goods or burden of any description; and

water, fuel or accumulators used for the purpose of the supply of power for the propulsion of a vehicle or, as the case may be, of any vehicle by which a trailer is drawn, and loose tools and loose equipment are not to be deemed to constitute goods or burden of any description.