23. On a public highway belonging to the “special” class, the maximum total loaded mass of a combination of road vehicles consisting of 3 vehicles shall be computed by adding the maximum axle loads prescribed by section 13, up to and including:(1) 105,000 kg where the distance between the centre of the front axle of the tandem of the tractor and the centre of the rear axle of the combination of road vehicles is 28 m or more;
(2) 105,000 kg less the product of 1,200 kg per 300 mm under the 28 m length prescribed for paragraph 1.