108.553—Survival craft launching and recovery arrangements using falls and a winch.
Survival craft launching and recovery arrangements, in addition to meeting the requirements in § 108.550, must meet the following requirements:
(a)
Each fall wire must be of rotation-resistant and corrosion-resistant steel wire rope.
(b)
The breaking strength of each fall wire and each attachment used on the fall must be at least six times the load imparted on the fall by the fully-loaded survival craft.
(c)
Each fall must be long enough for the survival craft to reach the water with the unit in its lightest seagoing condition, under unfavorable conditions of trim and with the unit listed not less than 20 degrees either way.
(d)
Each unguarded fall must not pass near any operating position of the winch, such as hand cranks, payout wheels, and brake levers.
(e)
Each winch drum must be arranged so the fall wire winds onto the drum in a level wrap, and a multiple drum winch must be arranged so that the falls wind off at the same rate when lowering, and onto the drums at the same rate when hoisting.
(f)
Each fall, where exposed to damage or fouling, must have guards or equivalent protection. Each fall that leads along a deck must be covered with a guard that is not more than 300 millimeters (1 foot) above the deck.
(g)
The lowering speed for a fully loaded survival craft must be not less than that obtained from the following formula:
(1)
S=0.4 (0.02 H), where S is the speed of lowering in meters per second, and H is the height in meters from the davit head to the waterline at the lightest seagoing condition, with H not greater than 30, regardless of the lowering height.
(2)
S=79 (1.2 H), where S is the speed of lowering in feet per minute, and H is the height in feet, with H not greater than 99.
(h)
The lowering speed for a survival craft loaded with all of its equipment must be not less than 70 percent of the speed required under paragraph (g) of this section.
(i)
The lowering speed for a fully loaded survival craft must be not more than 1.3 meters per second (256 feet per minute).
(j)
If a survival craft is recovered by electric power, the electrical installation, including the electric power-operated boat winch, must meet the requirements in subchapter J of this chapter. If a survival craft is recovered by any means of power, including a portable power source, safety devices must be provided which automatically cut off the power before the davit arms or falls reach the stops in order to avoid overstressing the falls or davits, unless the motor is designed to prevent such overstressing.
(k)
Each launching appliance must be fitted with brakes that meet the following requirements:
(1)
The brakes must be capable of stopping the descent of the survival craft or rescue boat and holding it securely when loaded with it full complement of persons and equipment.
(2)
The brake pads must, where necessary, be protected from water and oil.
(3)
Manual brakes must be arranged so that the brake is always applied unless the operator, or a mechanism activated by the operator, holds the brake control in the off position.