EMPIRE FIBRES

Otago Daily Times, Issue 21952, 13 May 1933, Page 24

EMPIRE FIBRES

SISAL FOR MARINE CORDAGE. (From Our Own Correspondent.) LONDON, March 31. The Admiralty, desiring to make _ use of Empire produce so far as possible, have been carrying out experiments with cordage manufactured from sisal hemps. Tests were comriienced in 1926 in Conjunction with the Imperial Institute Advisory Committee on Vegetable Fibres to ascertain the degree to which ropes manufactured from Empire hemp could resist the action of sea water as compared with ropes made from manila. _ Over a six months’ exposure the sisal compared very closely with the manila. In the final stages of the twelve months’ trials the manila gave the best results. Generally, however, the sisal fibre can be regarded as satisfactory so far as its capacity to resist the. action of sea water is concerned. A large number of satisfactory reports on the use of sisal for general purposes were received. Generally, as regards flexibility and ease of handling,, it was considered to be up to the standard of manila, and, except in a,few instances, no difficulty was experienced as regards swelling. In some cases, when used for tackles, noticeable stretching was reported, and when wet it is inclined to become slippei’y and needs care inhandling. , In summarising the results it is stated in a report issued by the Imperial Institute that the following defects can be definitely regarded as peculiar to marine cordage made from sisal: —(1) Shrinks in length when wet, and requires tending continually in wet weather. (2) Swells when wet, although, except in two or .three isolated cases, it was insufficient to interfere with its working through blocks. (3) Elongates consider - ably under load, particularly when wet, and in some cases becomes definitely longjawed. Under some conditions •, it tends to return to size after load is removed, but generally, the extension is .m&re or less permanent. (4) Becomes, greasy and slippery, is difficult to handle when wet, and greater care is necessary when working it round a cleat or bollard, (o) After prolonged use it tends to chare and fray and becomes discoloured. , In considering the-result of the trials, the question of sisal being an Empire product must be given prominence, it the two fibres—sisal and manila—were on an equal footing as regards their origin, the results of the, trials,would not warrant any departure from the existing practice. As, however,_ the policy of the Admiralty is to .give a preference to products of the Empire, the results are regarded as sufficiently promising to warrant the partial adoption of sisal, and (so long as supplies of sisal can be obtained at satisfactory prices) arrangements are being made for 50 per cent, of the service requirements for towing hawsers, heaving ana hauling lines to be made, from sisal, also for its entire adoption m the manufacture of cordage for about 30 different purposes. \