7. The Department authorises the use on roads of trailers constructed or adapted for use as grass cutters or hedge trimmers notwithstanding that such trailers do not comply in all respects with such of the requirements of the Construction and Use Regulations as apply to trailers, subject to the following conditions—
(a)the requirements of regulation 25 of the Construction and Use Regulations, so far as it applies to trailers, shall be complied with;
(b)the unladen weight of the trailer shall not exceed—
(i)1020 kilograms if drawn by a locomotive, a motor tractor or a heavy motor car, or
(ii)815 kilograms in any other case;
(c)the overall width of the motor vehicle by which the trailer is drawn and, except when it is actually cutting grass or trimming hedges, the overall width of the trailer shall not exceed 2.6 metres;
(d)except where the trailer is actually engaged in such operations, where it is being drawn in such a manner that its longitudinal axis and that of the drawing vehicle are parallel but lie in different vertical planes, the width of road occupied by both vehicles shall not exceed 2.6 metres.
For the purposes of this paragraph, the said width shall be taken as a distance equivalent to the distance which, if both vehicles were treated as if they were one vehicle at a time when the one is drawing the other in the said manner, would fall to be measured as its overall width;
except when the trailer is actually engaged in such operations, all cutting or trimming blades which form part of the machinery fitted to the trailer shall be effectively guarded so that no danger is caused or is likely to be caused to any person; and
the trailer shall not be driven at a speed exceeding 20 miles per hour.