Figure Standard Iron Pipe Stanchion
• Wood Post Stanchion. Wood posts can be used as stanchions (Figure 2-4) for handlines, or standing timber may be used if the path is through natural growth. Wood post stanchions should be 6 to 8 cm (2 to 3 inches) in diameter and should be notched near the top so rope handlines can be tied to them with a clove hitch.
A clove hitch is tied in the center of the rope and slipped over the end of the stanchion.
• Rock Anchors. Rock anchors are used to hold ends of handlines or other cables. Where handlines are placed parallel to a vertical rock face, they can be supported by rock anchors placed horizontally in the face of the rock instead of by vertical stanchions. Rock anchors used this way should be spaced according to the contours in the rock and up to 9 meters (30 feet) apart.
• Hole Drilling. Three methods of hole drilling in rock for pipe stanchions or rock anchors are discussed below.
Hand drilling. In hand drilling, hold the drill bit against the rock. After each hammer stroke, rotate the drill slightly so that a round hole is drilled. One man can hold the drill and strike it with a short-handled hammer. An inexperienced man can drill a hole 25 cm (10 inches) deep in ordinary rock in 30 to 60 minutes. For faster drilling, one man holds the drill and rotates it, while one or two other men strike it with hammers. Three inexperienced men should drill a hole 25 cm (10 inches) deep in about 15 minutes.
Gasoline-operated hammer. A gasoline-operated hammer can be used for drilling holes in positions where there is enough room for it to operate, and accessibility permits. It is faster than hand drilling.
Pneumatic drills. Pneumatic drills can be used in more accessible locations and are faster. A small portable gasoline-engine-driven compressor is available.
• Line Rigging. Wire or fiber rope can be used for handlines. However, wire rope is stiff and the ends of any broken wires produce severe cuts on the hands. Therefore, wire rope must be wrapped before use.
A marline-clad rope, if available, is a satisfactory material for such uses. Both fiber rope 1.9 cm (3/4 inch) in diameter and marline-clad wire rope with a l.9-cm (3/4 inch) outside diameter have the required strength. Fiber rope weighs less and is more flexible, but is not as strong as the same size wire rope. Wire rope is more durable, resists weathering, and offers greater resistance to stretching. To rig either rope, pass one end through the eye of a rock anchor at one end of the handline. Fasten this free end to the main portion of the rope to provide a firm hold. Splice or tie fiber rope with a bowline with the eye of the anchor in the bight of the knot; or fasten wire rope with clips or clamps.
Roll the coil of rope along the path at the base of the stanchions. If wooden post stanchions are used with fiber rope, raise the rope to the top at each stanchion, pull tight, and tie around the top of the stanchion with a clove hitch. If pipe stanchions are used, lift the wire fiber rope to the top of the stanchion, and insert a wire rope clip over the rope through the stanchion. Place the nuts on the ends of the U-bolt of the clip and tighten slightly. Pull the rope tightly past the stanchion, and securely tighten the nuts.
Construction continues along the path to the end of the handline or until the coil of rope is used up. Fasten the free end to a rock anchor the same as the beginning of the path. Where rock anchors are used to support the rope along vertical rock faces, feed the rope through the eyes of the anchors. In rigging wire rope, remove kinks along the path as they develop since they can cause stretching and deformation of the wire, weakening the line after erection.
Continue reading here: Part B Steps And Ladders
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