25.—(1) Subject to paragraph (2) where a trailer is drawn by a motor vehicle the driver (or in the case of a locomotive one of the persons employed in driving or tending the locomotive) shall be in a position readily to operate any brakes required by these Regulations to be fitted to the trailer as well as the brakes of the motor vehicle unless a person other than the driver (or in the case of a locomotive a person other than one of the persons employed in driving or tending the locomotive) is in a position and competent efficiently to apply the brakes of the trailer.
(2) This regulation shall not apply to a trailer which—
(a)in compliance with these Regulations, is fitted with brakes which automatically come into operation on the overrun of the trailer; or
(b)is a broken down vehicle being drawn, whether or not in consequence of a breakdown, in such a manner that it cannot be steered by its own steering gear.