The gabion, when wattled and sewed, is completed by cutting off the tops of the pickets 1 in. from the web, the bottom 3 ins., the latter sharpened after cutting, and driving a carrying picket through the middle of its length and a little on side of the axis. See that the middle of this picket is smooth. Three men should make a gabion in an hour.
Gabions may be made without the forms, but the work is slower and not so good. The circle is struck on the ground and the pickets driven at the proper points. The weaving is done from the ground up and the entire time of one man is required to keep the pickets in proper position.
If brush is scarce, gabions may be made with 6 ins. of wattling at each end, the middle left open. In filling, the open part may be lined with straw, grass, brush cuttings, or grain sacks, to keep the earth from running out.
[1123]. Gabion revetment.—The use of gabions in revetments is illustrated in [Fig. 20]. If more than two tiers are used, the separating fascines should be anchored back. Gabion revetments should be crowned with sods or bags.
The advantages of the gabion revetment are very great. It can be put in place without extra labor and faster and with less exposure than any other. It is self-supporting and gives cover from view and partial cover from fire quicker than any other form.
Several forms of gabions of other material than brush have been used. Sheet iron and iron and paper hoops are some of them. The iron splinters badly, is heavy, and has not given satisfaction. If any special materials are supplied the method of using them will, in view of the foregoing explanation, be obvious.
[1124]. Timber or pole revetment.—Poles too large for use in any other way may be cut to length and stood on end to form a revetment. The lower ends should be in a small trench and have a waling piece in front of them. There must also be a waling piece or cap at or near the top, anchored back. [Fig. 21] shows this form.
[1125]. Miscellaneous revetments.—Any receptacles for earth which will make a stable, compact pile, as boxes, baskets, oil or other cans, may be used for a revetment. Barrels may be used for gabions. Canvas stretched behind pickets is well thought of in a foreign service. If the soil will make adobe, or sun-dried bricks, an excellent revetment may be made of them, but it will not stand wet weather.