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Combination-Picket Holdfast

A COMBINATION-PICKET holdfast consists of two or more pickets. Figure 6-2 gives you an idea of how to arrange pickets in constructing a 1-1-1 and a 3-2-1 combination-picket holdfast.

In constructing the 1-1-1 combination, drive three single pickets about 3 feet (0.9 meter) into the ground, 3 to 6 feet (0.9 to 1.8 meters) apart, and in line with the guy. For a 3-2-1 combination, drive a group of three pickets into the ground, lashing them together before you secure the guy to them. The group of two lashed pickets follows the first group, 3 to 6 feet (0.9 to 1.8 meters) apart, and is followed by a single picket. The 1-1-1 combination can stand a pull of about 1,800 pounds (810 kilograms), while the 3-2-1 combination can stand as much as 4,000 pounds (1,800 kilograms).

The combination of the pickets grouped and lashed together and the small stuff secured onto every pair of pickets makes the combinationpicket holdfasts much stronger than the singlepicket holdfasts.

The reason for grouping and lashing the first cluster of pickets together is to reinforce the point where the pull is the greatest. The small stuff links each picket to the next, thereby dividing the force of pull so that the first picket will not have to stand all of the strain. Using 12- to 15-thread small stuff, clove hitch it to the top of the first picket. Then, take about four to six turns around the first and second pickets, going from the bottom of the second to the top of the first picket. Repeat this with more small stuff from the second to the third picket, and so on, until the last picket has been secured. After this, pass a stake between the turns of small stuff, between EACH pair of pickets, and then make the small stuff taut by twisting it with the stake. Now, drive the stake into the ground.

If you are going to use a picket holdfast for several days, it is best to use galvanized guy wire in place of the small stuff. Rain will not affect galvanized guy wire, but it will cause small stuff to shrink. If the small stuff is already taut, it could break from overstrain. If you HAVE TO use small stuff, be sure to slack it off before leaving it overnight. You do this by pulling the stake up, untwisting the small stuff once, and then replacing the stake.

Combination-Log-Picket Holdfast

For heavy loads or in soft- or wet-earth areas, a COMBINATION-LOG-PICKET holdfast is frequently used. With this type, the guys are anchored to a log or timber supported against four or six combination-picket holdfasts. (See fig. 6-3.) The timber serves as a beam and has to be placed so that it bears evenly against the front row of the pickets. Since the holding power of this setup depends on the strength of the timber and anchor line as well as the holdfast, be sure to use a timber big enough and an anchor line strong enough to stand the pull.

Rock Holdfast

ROCK holdfasts are made by inserting pipes, crowbars, or steel pickets in holes drilled in solid

Figure 6-2.\Combination-picket holdfast: A. 1-1-1 combination, B. 3-2-1 combination.

Figure 6-3.\Combination-log-picket holdfast.

rock. Using a star drill, drill holes in the rock 1 1/2 to 3 feet (75 to 90 centimeters) apart, keeping them in line with the guy. Remember to drill the holes at a slight angle so that the pickets will lean away from the direction of pull. Make the front hole about 1 1/2 to 3 feet (75 to 90 centimeters) deep and the rear hole 2 feet (60 centimeters) deep (fig. 6-4). After driving pickets into the holes, secure the guy to the front picket. Then, lash the pickets together with chain or wire rope to transmit the load.







Western Governors University
 


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