11. For the purposes of Type I tests conducted, in accordance with paragraph 1.3 of Annex II to Council Directive 71/320/EEC, on a mobile crane falling within paragraph 9(3) of this Schedule, the reference to a laden vehicle is to be taken to be a reference to a vehicle laden with the heaviest weight possible without the sum of the weights transmitted to the road surface by all the wheels of any one axle exceeding 12,500 kilograms.