A Tractor-Powered Method for Installing Earth Anchors during Fence Construction

Abstract

Fencing is an important tool for managing rangelands. However, the cost of conventional fencing is often prohibitive for anything other than boundary or important cross fences (Moore et al. 1968). Suspension fences cost about half as much as conventional fences, and, under many conditions, will turn cattle equally well, last as long, and require less upkeep (McNamee and Kinne 1965). A suspension fence requires strong comer assemblies. A typical comer is double braced with the first brace post guyed to a ‘deadman” (a large object such as a rock or section of post) buried 60 cm deep midway between the corner and first brace post. Installing a deadman is hard, time-consuming work. Under most soil conditions it takes one man approximately 45 minutes per deadman if a power auger is used to dig the hole. This paper describes the adaptation of a tractor-powered post hole digger to screw earth anchors into the soil for use as a deadman, thus reducing the installation time per deadman from 45 to 10 minutes. It also reports on the suitability of earth anchors for holding fence-corner assemblies. The use of a tractor to install screw-in earth anchors requires an adapter to transmit the turning force of the auger power head to the earth anchor. The adapter (Fig. 1) fits on the power head in place of the auger and holds the eye of the earth anchor so that the power head can screw the anchor into the soil. The materials needed to construct the adapter are readily available ih most communities from some of the larger hardware stores (Fig. 1). The earth anchor used with the adapter shown in Figure 1 had an 1 1 / 16-inch (18 mm) rod, a 6-inch (15 cm) helix, and an overall length of 48 inches (122 cm). If an anchor with a different sized eye or rod were used, the dimensions of the adapter would need to be adjusted accordingly. Also, if the shaft of the power-head were different in size than the one used, a different sized adapter sleeve would be needed (Fig. 1). Earth anchors should be lined up and installed before the posts are set; this allows room to operate the tractor. The anchor is started perpendicularly to the ground and turned until the helix is covered by the soil surface. The anchor shaft is then angled towards