MORE ABOUT ROPES

Hawke's Bay Herald-Tribune, Volume 81, Issue 31, 30 October 1937, Page 14

MORE ABOUT ROPES

This is a continuation of last week'e article out of Qilcraft's "Pioneering." Ropes are measured and desorjjxftd by their cireumferences in inche^ a three-inch" rope being just under an inch in diameter. The word "?ope'' is not usually applied to anything less than one inches in oircumference. smaller sizes being described as cord, line, and so on. Cords are usually distinguished by the number of yams— six, nine, twelve, etc. , In making the rope the aim is to make the tension on the stranda aud yams composing the strands equal. But, since this is impossible, it is always necessary to take out the kinks or "turns" in a new rope for the first. two or three days it is used. If a uew rope is so kinky that it cannot be used, the twist can be removed by draggiug it backwards and forwards along the ground. The method used at sea to take the turns out of a new rope is to lay it left-handed; the end is thon taken through the coil and . hauled through. If this is done three or four times the kinks will have been takou out evenly for the whole length. j If a rope is held up, it wjll be

noticed that the strands run from the bottoiq lef t hand tp the top right hand. The twisting of the strands together is called the lay, and iu this case the rope is right-handek Three strands laid up together right-handed form a hawser-laid rope. Four strands laid up together right-handed, sometimes rouud a core, form a ehro.ud-laid rope. On the Continent of Europe hawserlaid ropes and sbroud-laid ropes are usually laid left-handed. That, howoverj, causes complications ouly whea it comes to splicing, and does not materially affect the. use of the ropes for knotting and lashing. It wiU meau that the twist of a new rope will have to be taken out the opposjte way to that previously described, Roughly, the. safe working load for hemp ropes, which are gtronger and1 more durable than cotton, may be taken being equal in cwts. to the square of the circumference in inches, so tha,t the safe loading for a three-inch rope would be nine cwts. Don't put the same load in a rope that has beeu in use for some time that you wpuld put on a new rope. These figures, however, Ieave, a considerable matgin of safetyj the. aetual breaking load is about sev'en timea that weight, but do not ruu the risk of eounting on a rope to, take a big overload, for it migbt not. be up to it. Knots, turns and hitehes weakeu a rope by forming a bend which distrL butes the strain unequally on the fibres. For instance, it has been calculated that an eye-spKoe weakens a rope by ten per cent., a short spUce by twe.nty per cent., a timber hitch by thirty-fiye per cent., a clOYe hitcn or running bowline by forty per cent., and a reef knot or sheet-bend by fifty per cent. This means, that you will "have to. go easy on a. rope that hau been knotted or splicedj it also ac.counts for the reas.on that. you will sometimes find a rope breaks at. the knot. All ropes and cordage should be kept as dry as possible, and should not be coiled to put away damp or they will becomd mildewed very quickly. Mildew usually causes a defeet whieh "Will only become apparent when the rope suddenly breaks unexpectedly. Wet ropes should be laid in the shade to dry before being coiled up. A stif? and ha.rd rope i$ likely to eause trouble, espeeially if it is to run through a block. It, can be softened by placing in water aud then by bringing ihe water to the boil. After this the rope should be atretched straight utnU it is thoroughly dry. This pcpcess weakens the. Strength of the rope, but not yery appieciably.