Cargo gear and rigging

46 CFR §28.885

Cargo gear. (a) The safe working load (SWL) for the assembled gear shall be marked on the heel of each cargo boom, crane, or derrick. These letters and figures are to be in contrasting colors to the background and at least one inch in height. The SWL is construed to be the load the gear is approved to lift, excluding the weight of the gear itself. (b) All wire rope, chains, rings, hooks, links, shackles, swivels, blocks, and any other loose gear used or intended to be used in cargo loading or unloading must be commensurable with the SWL rating in paragraph (a) of this section. This gear shall be visually inspected by the vessel's captain or his designee at frequent intervals, and in any event not less than once in each operating month. (c) In addition to the inspection required in parag…

NAVEDTRA 14067 §3-4

Wire rope handling and care Wire rope aboard ship is used where high strength and low stretch are needed — standing rigging, boat falls, cargo runners, and towing gear. It is made of steel wires laid into strands around a core, and its behavior depends on how many wires and strands, and the core (fiber core holds lubricant and is flexible; independent-wire-rope core resists crushing and heat). Wire rope must be handled to avoid the damage it does not recover from: never allow a kink to form and then pull it taut, because a kink permanently distorts and weakens the wire; unreel and coil it so turns are not forced in or out (roll the reel or turntable rather than throwing off loops); keep it off sharp edges and small-radius bends; and keep it clean and lubricated so the wires slide over one…

NAVEDTRA 14104 Ch. 10 — Cranes

Cranes are designed to meet the following criteria: 1. Hoist, lower, top, and rotate a rated load at the specified speed and against a specified list of the ship. 2. Handle 150 percent of rated load at no specified speed. 3. Withstand a static, suspended load of 200 percent of rated load without dam or distortion to any part of the crane or structure. The types of cranes installed on ships vary according to the equipment handled. The crane equipment generally includes the boom, king post, king post bearings, sheaves, hook and rope, machinery platforms, rotating gear, drums, hoisting, topping and rotating drives, and controls. Some of the components of cranes include booms, king post bearings, sheaves and ropes, machinery platforms, rotating gear and pinions, and drums. Booms A boom, used a…

NAVEDTRA 14256 — Blocks

Blocks are used in combination with rope and wire to hoist and move loads. The block consists of a metal shell which supports both ends of a pin. The shell also houses a grooved pulley that revolves on the pin. Attached at one end of the first block is a freely revolving hook. Blocks may be classified as single, double, triple, etc. according to the number of pulleys housed in the shell of the block. Depending on the various combinations of blocks available to do the job, the mechanical advantage can be increased indefinitely. TYPES AND USES - Continued

NAVEDTRA 14256 — Using the Block

1 Secure one end of the rope or ropes to the load (1) to be moved. 2 Pass the other end of the rope over the pulley (2) of the block attached to some type of solid support. 3 Apply the necessary manpower to the end of the rope to lift the load.

NAVEDTRA 14343 §4-5

Emergency towing rigs and hawser handling A vessel may be called on to tow a disabled ship or to be towed. The tow hawser is a heavy line or wire; nylon is favored for its elasticity, which absorbs the shock of surging seas, while wire gives strength with less stretch. The towing connection uses a bridle (a two-legged span shackled to strong points, usually the disabled vessel's anchor chain or bitts) so the strain is shared and the tow tracks straight. A pendant (a length of chain or wire between bridle and hawser) resists chafe at the fairlead and adds catenary weight. The catenary — the sag of the towline — is critical: it acts as a spring, smoothing out surge loads, so towing speed and hawser length are adjusted to keep a good catenary and prevent the line coming bar-taut. To pass a t…