Page 129 - Moving the Earth_ The Workbook of Excavation

ROCK, SOIL, AND MUD

ROCK, SOIL, AND MUD 3.23

necessary to drill and bolt. Spruce, although soft, is tough and resists splitting, can be nailed, and
is lighter than the hardwoods.
Green lumber can be used. It is tougher and heavier than after curing.
Figure 3.15A shows a sample of very light construction. The loops shown at each end may be
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of any size cable from ⁄ 8 inch up, fastened with two clamps. A chain is hooked to both of these
and to the shovel bucket when the mats are moved. Three-eighths-inch chain is satisfactory for
ordinary service with light shovels.
It is a good plan to make up a special chain about 2 feet longer than the platforms are wide. Round
hooks should be used on the ends, preferably the lock-on type. The center should have a ring and a
special hook large enough to hook on the bucket, or on the drag chain links next to the bucket.
A mat may be lifted and dragged by one side loop, but this is not as convenient as using two.
The siderails, above the deck, prevent the shovel from sliding off the side. They get in the way
occasionally but on the whole are well worth having.
When nails are used, they should be long enough to hammer through the wood. The projecting
point should be hammered over flat.
Bolts should have washers on both ends. Heads should be countersunk into the deck.
The laminated platform in Fig. 3.15B is suitable for any but the roughest service and will support
light trucks. It is heavier to handle.
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The heavy-duty type in Fig. 3.15C will take any abuse a ⁄ 2 -yard shovel can give it, for a while.
It is suitable for use on rough or frozen ground, and among stumps and boulders, but it is too
heavy to be convenient for ordinary soft ground.

FIGURE 3.15A Butt joint platform.