Elementary Rigging

■ 17. Importance.—The engineer often makes his own machines for use in heavy work and as substitutes for tools and machines that are unavailable. The machines are simple, but they save much labor. By "rigging" is mean; the handling of rope (manila or wire) and chains with blocks and tackles to raise, move, or hold heavy loads. The combinations which the engineer rigs up with rope are really simple machines. This chapter explains the principles and methods of rigging, which will be one of your most valuable skills as an engineer. Make a thorough command of this skill a part of your personal Army knowledge.

■ 18. Care or Rope.—Proper care of rope lengthens its usefulness. Observe the following precautions:

c. Do not store in wet, damp, or hot places.

b. Clean muddy rope by washing in water.

c. Dry before storing, but do not use artificial heat.

d. Avoid pulling over sharp edges.

e Avoid dragging rope through sand or dirt. Sand has an abrasive action on the inner fibers.

1. Keep rope free of contact with acid, alkali, or other damaging chemicals.

p. Use knots that can be untied and will not have to be cut.

h. Repair broken strands as soon as possible.

i. Slaken dry, taut lines when exposed to rain or damp weather.

j. Always whip loose ends of rope, and when cutting a length of rope put on two whippings and cut between them, k. Inspect rope frequently.

■ IB. Uncoiling and Coiling Rope.—a. New rope is coiled into bales usually containing 1.200 feet each. To uncoil, begin with the end in the center of the coil. The rope should

31 19-20

uncoil in a left-hand (counterclockwise) direction. If it uncoils in the wrong direction, turn the bale over, pull the end through the center, and uncoil from the opposite side.

b. Coil rope In a right-hand (clockwise) direction (see flg. 43(5» • Mark the end of the rope that will enter the coil last; this is helpful in uncoiling.

■ 20. Definitions.—a. Knot.—A knot is a tie or fastening made with a rope or cord. Types of knots Include the following:

(1) Bend knot which fastens one rope to another or to a ring or loop.

<2) Hitch knot, a temporary knot used to fasten one rope to another, or to spar or post, so as to be readily undone.

Notk.—These termi are often loosely applied; the same tie. fcr example, Is called a sheet bend, weaver''» knot, or weaver's hitch

(3) Splice, a knot joining two ropes, or parts of same rope, by interweaving strands of two parts.

(4> Lashing, a knot which ties together objects such as spars or poles by means of a rope. The individual ropes used in this knot are also called "lashings"; rope of this ktnd, used to lash pontons, is about 18 or 20 feet long and l/2 inch in diameter. It has an eye splice at one end and is whipped at the other end.

b. Special terms.—(!) Anchorage.—Any means, natural or Improvised, for securing guys, ropes, struts, etc.

(2) Bight.—Loop formed on rope so that the two parts cross (or lay alongside) each other.

(3) Chock.—Bring blocks together until they touch each other.

(4) Frapplnq.—Several turns of rope taken around lashing turns, used to keep the lashing tight and in place.

(52 Guy.—Rope, chain, or spar attached so as to steady an object.

(7) Mousing.—Closing mouth ot hook by lashing to prevent rope or load from becoming dislodged.

<8) Owrhaul.—To separate the blocks in block-and-tackle rigging. 32 2Q_23

(9) Reeve.—Thread blocks with rope in assembling block and tackle.

(10) Return.—Each part oi rope between blocks or between either end and a block.

(11) JSoand (run) in.—Bring blocks closer together.

(13) Seizing.—Lashing the running end to the standing part of rope.

(14) Standing end (part).—Whole rope less running end.

(15) Tackle.—Assembly of ropes and blocks.

(16) Transom.—Horizontal spar.

(18) Whipping.—Binding or lashing end of rope to prevent uniaying.

■ 21. Knots and Thuf Uses.—For any one job a particular knot Is the best to use; that is why there are so manjr knots an engineer must know. Learn to tie all the knots and learn to use them at the proper time. Figures 44 to 48, inclusive, illustrate the most common knots.

■ 22. Splices.—The three principal steps in splicing a rope are unlaying the strands, placing the ends together, and tucking the ends of the strands. No attempts should be made to learn to splice without having rope In the hands and actually executing the operations. Marlinespikes or ben pins are desirable, but no special tools are necessary.

B 23. Short Splice (fig. 49).—o. Short splicing is the best method to Join two ropes when an appreciable increase of

elevation

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