A FLOOD GATE.

Te Aroha News, Volume VI, Issue 336, 23 January 1889, Page 3

A FLOOD GATE.

! Mb Jesse Pabkinson, of Thorpe, Nelson, ■writes to us :—: — ' I will now try to describe to you a flood gate to fence across large creeks or small rivers (which is largely used about here). You put up two good strong piles, one on each side of the river, well back from the flood, sunk sft or 6ft into the ground, well braced and rammed, and sufficiently above ground to carry a wire rope or cable well above the floods. The affair will look something 7/ke the accompanying sketch.

Bore ab a proper height for tho cable to go through lin. holes in each of the piles. Pub the cable through one of the holes ; open out the strands of the cable and fasten them to the post with four or five common fencing staples to each strand. In the other post bore another hole, above or below the cable hole. Now fasten a ropo with 2£in. on the cable, well back from the post, bring the other end of the rope through the hole in tho post. Have a nice round, tough, and hard sapling for a roller about 2ft long, and from 7in to 9in through ; bore two holes through each end at right angles with each other, so as to break the quarters, and one small hole in the centre. Put the rope through the centre hole and take a turn round the piece of sapling. Now take a crowbar, and put it through one of the holes in the end of the roller and pull v, down ; another man takes another crowbar and puts it in one of ■ the holes at the other end of the roller, and pulls down and holds till the first man puts his crowbar in and pulls down again ; so, in four pulls each, or eight pulls together, the roller is worked round once. When the cable is tight, fasten and take another roller (or the same one), and put on the cable and tighten it up in the same way as the rope. the crowbars are not long enough to tighten it up, fasten levers on to them. You must see that nothing gives way or breaks, or look out for consequences. Have a short piece of iron bar to put in a hole in the roller, and let it fasten against the post, and then all will be safe. Most people here use two long bolts with long threads and nuts on them, to go through the posts and tighten up the cable 3 instead of the staples and roller. The bolts and nuts are made with a ring at the end of the bolt, and the cable rove through the ring the same as a loop is worked on the end of a rope. A wire brace on the up-stream side, or a wooden brace on the opposite side of the flood-gate posts is required. Take two rails Bor 9ft. long and Dail good long palings on to them (or better still, two light scantlings, and nail boards on them). When you have got enough of these gates made to go across the river tie them to the wire cable with flax. You can then keep tightening till they are all in proper places. Then cut some fencing wire into proper lengths to go over the cable and under the top rail or scantling and twist the two ends together, -putting a wire on each end of each gate, back of one of the palings from the end. The gates will then hang loose and float down the river in times of flood, and rise up if struck by a log and let it pass under. Put the cable high enough when sagged down by the heat ot the sun and weight of the gates to allow any trees coming down the river in time of flood to pass under it without catching. The gates ought to just rest on the gravel with a slight slant by the bottom down the river. Footbridges are made with wire cables about here with two piles at each side of the river, put in the same way as the piles for the flood-gate, and two wire cables put across the river and fastened to the four piles with four long bolts with long threads and nuts. The long threads are for tightening up the cables. If the span of the river is long the piles must be sunk in deep and well braced, or of course they will sag in fl'ards and let the bridge down. To stop the bridge from swaying too much sideways the decking is generally put on in the following manner : — A long scantling is laid across the wire cables, and two short flat pieces of iron bars with their bottom ends welded round to go through two auger holes in the scantling and to fasten with nuts on the lower side of the scantling. The iron bars should have four or five small holes punched through them to put wires through to form handrails, and keep children from falling off the bridge. There ought to be a larger hole punched through near the top, and a round iron bar bent at right angles to go through and fasten with a nut, the bottom end to be flattened out and bent at a proper angle to lie flat on the end of the scantling. The scantling should have a hole bored through it> to come under a hole to be punched through the flat end of the bar, which should be fastened to the scantling with a bolt and nut. Cut out of the scantling two notches about 1 inch deep just where they rest on the wire cables wide enough to drop over the cables. These notches will bold the scantling and cables in their places. The scantling should rest on tho cables at" about 8 or 10 feet apart, placing shorter and lighter scantlings at suitable distances between them ; then nail the decking on the scantling. If any one objects to go to the expense of the iron bars they can nail battens on the long scantlings to run the 3tnall wire 9 through, and other battens for braces instead of the iron bars. I would give a full working plan of these bridges if I could, but I am afraid I could not do it so that all readers could understand it. J will therefore leave it to you or some one else to supply my deficiency in that respect.