Quantcast INSTALLATION OF NEW WIRE ROPE.

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TB 55-1900-232-10
B-6.3 INSTALLATION OF NEW WIRE ROPE. Ideally, new wire rope should be broken in by using it first with a light
load. This will help ensure a straight fairlead onto the drum, but the line must be loaded more heavily in order to seat
properly on the drum for later heavy use. In each layer of wire rope on the drum, the rope rides in the "grooves" between
the wraps on the next lower layer If the wire is wound on the drum under too light a load, the required number of wraps
may not go on the drum and the space between the flanges of the drum may not be completely filled The tension load on
the wire at the point at which it leaves the drum can force the rope down between the wraps and bury it in the lower
layers. Damage to the individual strands and lays of the rope at the contact point and in the lower wrap can occur. See
Section B-10 for further information on the relationship of wire lay to tight winding of the first layer on the winch drum.
CAUTION
Sudden application of a load to wire rope by rapid acceleration causes stress much
greater than the weight or resistance of the tow. Avoid such strain on the rope by
employing gradual acceleration.
NOTE
The need to wind the towline on the drum under fairly high tension, approximately 5
percent of the breaking strength, holds for both smooth and grooved drums.
Using stoppers to load the wire bight by bight is one way to approach the problem but is cumbersome and time-
consuming. During the construction of the first four ARS 50 Class ships, a lightweight cable brake was utilized to aid in
installing the wire-rope towing hawsers on those ships. This device, called a Wallis Brake, is shown in Figure B-5 and
discussed in the following paragraph As designed, this cable brake permitted continuous loading of the wire rope under
tension
The Wallis Brake is first tied down to a strong point aft of the drum. In the case of a towing machine or winch, there is
usually a strong point on the fantail such as an H-bitt or a heavy-lift roller These devices are not intended to be pulled on
in the forward direction, but they are built for much heavier loads than they will be required to withstand while sup- porting
a cable brake To install the wire, the bitter end is passed through the brake and onto the winch or the brake is opened by
removing the spring assembles and the top plate. The wire to be loaded on a winch may then be placed on the bottom
plate of the brake The top plate and spring assemblies may then be reinstalled. The spring assemblies may then be
tightened with the clamp nuts until the proper ten- sion is reached. Once the cable brake has been properly adjusted, the
rope is wound onto the winch in a continuous manner until all the wire is on the winch drum.
When new wire ropes are put m service as towing hawsers or pendants, their identification (see Section B-2) should be
recorded in the Towing Hawser Log described in Appendix F
B-7 STOWING
When the towing hawser is to be removed from the drum, it should be wound neatly on a reel and stored in an acid-free,
dry, protected location. Whenever a wire rope towing hawser is to be stored for some time, first lubricate it with MIL-G-
18458 grease and keep the outer layer lubricated with the same grease throughout the storage period.
Other wire ropes such as beach gear, pendants, etc., may be stowed below deck in open coils in clean, dry, protected
bins. If galvanized, these wire ropes may be stowed without the recommended outside protection layer.
B-5


 


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