185 



HOPE MAKIXii. 



ROPE MAKING. 



188 



yarn bears its own strain unaided, it will break at its weakest part ; 

 whereas, if combined, the mean strength of each will be rendered avail- 

 able. Huddart'a flat-rope machine, of more recent invention, is shown 

 in part in.R'y. 5. Supposing four round ropes be needed to make one 

 flat rope, four reel* are so placed that the ropes can unwind from them 

 with facility, and pass side by side through a steam-heated box, 

 where the tar becomes a little softened, and the ropes more easily 

 worked. They next pass through a groove or recess closed in tightly 

 at top, bottom, and sides, except holes at the sides to admit large 

 needle-*. A piercer, or *harp-(>ointed rod of steel, is then forced 

 entirely through the whole of the four ropes, by leverage produced by 



l>ower; anil A man immediately passes a needle and thread 

 through the hole. Two piercers are employed alternately, one on 

 either edge, making holes as fast as two men can introduce needles and 

 thread. The thread here spoken of is sometimes yarn as much as 

 half an inch in thickness, requiring great force to draw it tightly. 



Much attention has been devoted to the discovery of the best 

 method of preserving ropes from decay, especially when exposed to 

 the action of water. The operation of tarring, which has been almost 

 universally practised for this purpose, effects it very imperfectly, and 

 materially diminishes the strength of the cordage. Taking the mean 

 of several experiment* by Dubamel, it seems that untarred ropes bore 

 a greater weight, by nearly 30 per cent , than those to which the tar- 



rocess had been applied ; and he states that it is decided by 

 experience that white cordage in continual service is one-third more 

 durable than tarred, that it retains its force much longer when kept in 

 store, and that it resists the ordinary injuries of the weather one-fourth 

 Notwithstanding these facts, it is found that for cables and 

 ground -tackle, v. hich are much exposed to the alternate action of 

 water ami air, tarring u a valuable preservative ; though cordage that 

 i only superficially tarred in Kiid to be stronger than such as is tarred 

 tin-. r_"h"'-.t. .-UK! better able to be.ir the alternations of wet and dry. 



nioval of the defects and bad qualities of common tar was the 

 object of a patent taken out by Mr. Chapman. Unsuccessful attempts 

 had been made to substitute oils and various fat substances, which 

 would be inaoluble in water, for tar ; but they had been found to 

 impede the operation of twisting. Chapman improved the ordinary 

 tar, first, " by boiling the tar in water one or more times, each of 

 liieli extracts a portion of its superabundant acid, and its mucilage, 

 which contains a disengaged acid ;" and, secondly, " by continuing these 

 processes until the tar has thrown off a larger portion of its essential 

 oil, and becomes more pitchy than usual ; and, finally, by restoring the 

 requisite plasticity through the addition of substances less injurious 

 and less volatile, and therefore more continuous : namely, by the addi- 

 tion ..i suet, tallow, animal oils, or suitable expressed oils." Of the 

 advantages attending this process, an idea may be formed from the 



ned statement of the relative strength of the cordage without 

 any tar, with common tar, and with Chapman's purified tar. The rope 

 contained twelve yarns in each strand ; part was tried immediately, 

 and the rest steeped in water for about three months, then removed to 

 a foundry stove for three months, and finally kept at the ropery nine 

 months ; when another trial gave the following results : 



ft -.;,- -f r, tt, 



Common tarred 

 Tarred with purified tar 



Portion at original 

 strength retained. 

 . V 7 per cent. 



. -o ,. 



. 43-8 



Sir Joseph Banks had some ropes tarred with leak tar, by way of 

 experiment, and found them to be one-third stronger than those done 

 with common tar. Tanning has been tried for the preservation of 



The 

 , have al ' 



chief substance used for this purpose. 



Mr. Chapman gives the following notice of the mode of classifying 

 the work in her majesty's dockyards. Petersburg hemp U mostly 

 used for cables and cablet* ; Italian hemp for bult rope and breeching* ; 

 and Riga hemp for all other cordage. To make Petersburg hemp 

 .. 'JO'., the hemp is given to the hatcheller in bundles of 70 Ibs. ; 

 he takes out 7 Ibs. of shorts, and gives 63 Ibs. of heckled hemp to the 

 (pinner, who spins it into 18 threads of 170 fathoms and 34 Ibs. each. 

 To make Kiga hemp into No. 25's, the hemp is given to the hatcheller 

 in bundles of 56 Ibs.; he takes out S Ibs. of shorts, and gives 51 Ibs. of 

 heckled hemp to the spinner, who spins 18 threads of 170 fathoms 

 and 2\ Ibs. each. In uring Italian hemp, 16 Ibs. of shorts are taken 

 out of 112 Ibs, of hemp ; and the remaining 96 Ibs. are made up into 

 bands of 1] to 3( Ibs. each, according to the size of the yams to be 

 made. Much old-fashioned routine still prevails in the royal dock- 

 yards, in denning exactly how many porters, Darters, hatchellers, wheel- 

 turners, spinners, Ac., shall be employed for each ton of hemp. 



\\ .. have hitherto spoken only of hemp as the material employed ; 

 but several other kinds of vegetable fibre have been made use of 

 in th manufacture of cordage; and some appear greatly to exceed 

 hemp in strength. In a comparative trial made at Paris between 

 ropes made of hemp and of the aloe from Algiers, the latter was found 

 to bear 2000 kilogrammes, while the former, of equal size, bore only 

 400. Ropes have been formed also of long wool ; but they are only 



about one-third as strong as the best hempen cordage of the same size. 

 Ropes composed of fibres of hemp intermixed with threads of caout- 

 chouc are very valuable for some purposes, owing to their superior 

 strength and elasticity. Their power of bearing sudden jerks without 

 injury is a highly important property. Such a rope was used with 

 the grapnel or anchor of the great Nassau balloon, and was found to 

 arrest the balloon without any unpleasant check when the grapnel 

 caught. Ropes made of thongs of ox-hide twisted together are used 

 in the rope-bridges of Peru, and for some other purposes. Coir or 

 cocoa-nut fibre has lately been much used for this purpose, owing to 

 the high price of Russian hemp ; it wears well, weighs little, and is 

 cheap; and is useful for hawsers and warps owing to its great 

 elasticity. 



Wire Roptt. Iron is the substitute which is now engaging most 

 attention. Ropes formed of this metal are found to effect a great saving 

 of expense from their durability and superior lightness. From a paper 

 communicated by Count Breunncr to the British Association in 1838, 

 it appears that such ropes had been introduced about seven years 

 before, in the silver mines of the Harz Mountains, and had been found 

 so advantageous as almost entirely to supersede flat and round ropes of 

 hemp in the mines of Hungary, and most of those in the Austrian 

 dominion.". The count observes that these iron ropes are nearly equal 

 in strength to solid bars of the came diameter, and equal to hempen 

 ropes of four times their weight. One of them had been in use for 

 upwards of two years without any perceptible wear, though a common 

 flat rope i*rforming the same work would not have lasted much more 

 th:m one year. Tbe diameter of the largest rope in ordinary use is 

 one inch and a half, and it is composed of three strands, each con- 

 taining five wires. Great care is observed in the manufacture of these 

 ropes, that the ends of the wires may be set deep in the interior of the 

 rope, and that two ends may not occur near the same part. In use, it 

 is necessary that the ropes be wound on a cylinder of not less than 

 eight feet diameter, and be kept well coated with tar, to prevent 

 oxidation. IQ one case mentioned by Count Breunner, so great a 

 saving of power was effected, that four horses were doing as much 

 work with a wire rope as six with a flat hempen rope. 



Prior to the date of this memoir, patents had been obtained in this 

 country for the manufacture of wire ropes ; and they have since been 

 improved and acted upon. The wire ropes of Mr. Andrew Smith are 

 formed in various ways, according to their intended use. For stand- 

 ing rigging straight untwisted wires are employed, bound round with 

 cloth or small hempen cordage saturated with a solution of caoutchouc, 

 axphaltum, or other preservative from rust. Flat ropes may likewise 

 be made of straight wires, interwoven or wrapped with hempen yarn, 

 or sewed between canvas, &c. ; but the patentee prefers using them 

 with a slight twist. Other ropes are formed much in the same way 

 as those of hemp ; the wires taking the place of rope-yarns, and being 

 twUted into strand*, and combined into ropes, both hawser-laid and 

 cable-laid. The twisting should not be so hard as in hempen cordage; 

 and all the wires must be protected by an anti-corrosive composition, 

 or by coating with tin, zinc, Ac. In a patent obtained by Mr. Newall 

 of Dundee, for improvements in wire ropes, coating with the follow- 

 ing mixture is recommended : Tar, six parts; linseed oil, two parts; 

 and tallow, one |iart : the whole being melted together, and applied 

 while hot. In this patent it is proposed to twist wires round a core, 

 either of wire, hemp cord, spun yarn, or other material, to form a 

 strand ; and to lay such strands round a similar core when there are 

 more than three strands iu a rope. For joining the wires, Messrs. 

 Smith and Newall both recommend twisting their ends together for a 

 few inches ; and the latter also suggests the possibility in some cases , 

 of welding them. Wire ropes may be very conveniently and firmly 

 secured at their ends by passing them through the small end of a 

 conical collar, and doubling up, or ttptcttiny, the ends of the wires, 

 which may then be welded into a solid mass, or secured by running 

 melted brass or solder among them. The collars may then be attached, 

 in various ways, to anything with which it is desired to connect the 

 rope ; or they may, as suggested in Newall's patent, be screwed 

 together, so as to unite several lengths of ro]ie. Iron is the material 

 usually employed for wire ropes, but copper and other metals may 

 also be used. The annexed table, showing the comparative size and 

 weight per fathom for equal strength, gives the result of experiments 

 with the wire ropes of Mr. Andrew Smith, and may serve to show their 

 great superiority to those of hemp, which they surpass even iu 

 flexibility : 



Hemp Rope. Patent Wire Unix 1 . Kqnal to a 



8Ue. Weight per fathom. Rite. Weight per fathom. strain of 

 Indies. lli. oz. Inches. Ibs. o/. tons. cwt*. 



10 

 11 

 12 





 9 

 12 

 14 

 19 

 25 

 JO 

 36 



4 



15 

 

 

 3 

 S 

 6 

 

 



i; 

 it 

 l] 



ji 



i* 



2 

 2 

 4 

 5 

 1 



11 

 IS 



14 

 2 

 9 

 1 

 4 

 1 

 6 



12 



16 

 24 

 29 

 35 



10 



10 



15 







11 



18 

 6 

 6 

 S 



4 



Experiment* were made at Liverpool in 1857, to find the relative 



