5.—(1) Where the length of a forward or rearward projection of a load carried on a relevant vehicle exceeds 3 metres, one side marker must be fitted to the right hand side of the projection and one side marker must be fitted to its left hand side.
(2) The side markers under sub-paragraph (1) must be fitted so that—
(a)each side marker is, as near as is practicable, in a longitudinal plane;
(b)no part of a side marker extends beyond the end of the projection;
(c)the vertical distance between the lowest part of each side marker and the surface of the road is not more than 2.5 metres;
(d)the horizontal distance between each side marker and the end-marker (or, as the case may be, the rear marking fitted to the projection in accordance with the Lighting Regulations) does not exceed 1 metre; and
(e)each side marker is clearly visible, within a reasonable distance, to a person using the road on that side of the projection.
6.—(1) This paragraph applies where any relevant vehicle is carrying a load and—
(a)the length of any forward projection of the load exceeds 4.5 metres; or
(b)the length of any rearward projection of the load exceeds 5 metres.
(2) Additional side markers must be fitted to the right hand side and the left hand side of a forward or rearward projection so that the horizontal distance between the extreme projecting points of the relevant vehicle and the nearest points of any adjacent side markers does not exceed—
(a)2.5 metres in the case of a forward projection;
(b)3.5 metres in the case of a rearward projection.
(3) The additional side markers also must be fitted to the projection so that—
(a)each additional side marker is, as near as is practicable, in a longitudinal plane;
(b)the vertical distance between the lowest part of each additional side marker and the surface of the road is not more than 2.5 metres; and
(c)each additional side marker is clearly visible, within a reasonable distance, to a person using the road on that side of the projection.
(4) In determining the extreme projecting points of a relevant vehicle for the purposes of sub-paragraph (2), any part of a crane or other special appliance or apparatus, which is treated as a forward projection or a rearward projection by virtue of article 6(3), is to be disregarded.