Section 24(2)(ii) in The Dock Workers (Safety, Health And Welfare) Regulations, 1990
(ii)properly secured and securely fenced throughout its length on each side to a dear height of one metre by means of upper and lower rails, taut ropes or chains or by other equally safe means except that in the case of ship's accommodation ladder such fencing shall be necessary on one side only provided that the other side is properly protected by the ship's side;