Section 143.101 - Means of escape(a) "Primary means of escape" shall be fixed stairways or fixed ladders of metal construction.(b) "Secondary means of escape" shall be types approved for "primary means of escape" or portable, flexible ladders, knotted man ropes, and other devices satisfactory to the Officer in Charge, Marine Inspection.(c) Manned OCS facilities shall be provided with at least two "primary means of escape" extending from the uppermost platform level that contains living quarters or that personnel occupy continuously, to each successively lower working level and to the water surface. Working levels without living quarters, shops, or offices in manned facility structural appendages, extensions, and installations that personnel occupy only occasionally shall be provided with one "primary means of escape" and, when necessary in the opinion of the Officer in Charge, Marine Inspection, one or more "secondary means of escape."(d) Unmanned OCS facilities shall be provided with at least one "primary means of escape" extending from the uppermost platform working level to each successively lower working level and to the water surface. When personnel are on board, unmanned facilities shall also be provided with one or more "secondary means of escape," but not more than one will be required for every 10 persons extending from the uppermost working level of the facility to each successively lower working level and to the water surface, excluding facility appendages and installations, unless "secondary means of escape" from such appendages and installations are necessary in the opinion of the Officer in Charge, Marine Inspection.(e) "Means of escape" shall be suitably accessible to personnel for rapid facility evacuation.(f) When two or more "means of escape" are installed, at least two shall be located as nearly diagonally opposite each other as practicable unless such requirement is unreasonable or impracticable in the opinion of the Officer in Charge, Marine Inspection.