181 



ROPE MAKING. 



HOPE MAKING. 



133 



The best mode of supplying the hemp is in the form of a thin flat 

 skein. When the spinner has traversed the whole length of the rope- 

 walk (or sooner, if the yams are not required to be so long), another 

 spinner detaches the yarn from the whirl, and gives it to a person who 

 carries it aside to a reel ; while the second spinner attaches his own 

 hemp to the whirl-hook. The hemp, being dry and elastic, would 

 instantly untwist if the yarn were now set at liberty. The first 

 spinner therefore keeps fast hold of it all the while that the reeler 

 winil.- it up, walking slowly up the walk, so as to keep the yarn equally 

 tight all the way. When it is all wound up, the spinner holds it until 

 another is ready to follow it on the reel. Sometimes, instead of being 

 wound on a reel as they are made, the yarns are laid together in large 

 hooks attached to posts at the side of the walk until about four 

 hundred are collected together, when they are coiled up in a haul or 

 .skein, in which state they are ready for tarring. 



The common size of rope-yarns is from one-twelfth to rather more 

 than one-ninth of an inch diameter; 160 fathoms of white or untarred 

 yarn weighing from two and a half to four pounds. 



The next proce.4s \A warping the yarns, or stretching them to a given 

 length, in order that they may, when formed into a strand, bear the 

 strain equally. When the rope is to be tarred, that operation is 

 usually performed upon the yarns immediately after their being 

 warped ; as the application of tar to the yarns previous to their com- 

 bination in necessary to the complete penetration of the whole substance 

 of the rope. The most common method of tarring the yarns is to 

 draw them in hauls or skeins through the tar-kettle by a capstan ; but 

 sometimes the yarns are passed singly through the tar, being wound 

 off one reel on to another, and the superfluous tar being taken off by 

 passing the yarn through a hole surrounded with spongy oakum. 

 Great care is required in thU process that the tar may boil neither too 

 fart nor too slow, the common heat being from 212' to 250 Fahr. 

 The degree of impregnation necessary depend* on the kind of cordage ; 

 cables and water ropes needing a considerable quantity of tar, while 

 for standing and running rigging it is sufficient that the yarns be well 

 covered. 



In making large cordage, it il not usual to twist together, at once, as 

 many yams as would suffice to form a rope of the required thickness ; 

 a suitable number of yarns, frequently from fifteen to twenty-five, are 

 I into a strand, and three or more such strands are afterwards 

 combined into a rope. The twist of the strand is in an opposite 

 direction to that of the yarns of which it is composed ; in order that, 

 as before mentioned, the tendency to untwist in the individual yarns 

 may be counteracted, and taken advantage of to prevent the untwisting 

 of the strand. In closing or laying the rope, three strands, or some- 

 time* four, (in 'which case a small central strand or heart is added) are 

 stretched at length along the walk and attached at one end to separate 

 but contiguous hooks, and at the other to a single hook ; and they are 

 twisted together by turning the single hook in a direction contrary to 

 : the other three. A piece of wood called a fop (see fy. 3), in 



Fig. I. Lajlnf a Rope. 



'ii of a truncated cone, la placed between the strands, and kept 

 during the whole operation gently forced into the angle formed by the 

 strands, where they are united by the closing or twisting of the rope. 

 As the rope shortens in closing, one end only of the apparatus is fixed, 

 the other being on a moveable sledge, whose motion up the ropewalk 

 is capable of regulation by suitable tackle attached to it, or by loading 

 it with weights. The top also is mounted on a sledge, for closing large 

 cordage ; and its rate of motion may be retarded, in order to give 

 greater firmness to the twist of the rope. The art of the ropemaker, 

 in this operation, consists in so regulating the various movement* that 

 the strands may receive separately at one end just as much twist as is 

 taken out of them at the opposite end, by their twisting the contrary 

 way in ttip proceM of combination. 

 Such ii the method, more or lew modified by the kind of machinery 



employed, of forming a shroud-laid or hawser-laid rope; and such 

 appears to have been the whole process of rope-making until cordage 

 of very large size was called for by the progress of navigation. In 

 making such it was not found advisable to increase the number of 

 yarns in a strand ; it being difficult, when their number is very great, 

 to throw an equal strain upon each, and thereby obtain their aggregate 

 strength. To obviate this inconvenience, cables, or such large ropes 

 as are said to be cable-laid, are formed by the combination of smaller 

 ropes twisted round their common axis, just as shroud-laid ropes are 

 composed of strands twisted round their common axis. As cable-laid 

 ropes are harder and more compact than others, this mode of forma- 

 tion is adopted for ropes to be exposed to the action of water, even 

 though their thickness may not be very great. 



Ropes formed by plaiting instead of twisting are made use of for 

 some purposes in which pliability is especially needed ; they being 

 more supple and less liable to entanglement than those of the ordinary 

 make. Such ropes are preferred for sash-lines, clock-lines, &c., and 

 generally where the rope has to pass over pulleys of small diameter. 



Originally all the yarns composing a strand were selected of the same 

 length. This arrangement was defective, as it is evident that when 

 a number of yarns are stretched at length in a cylindrical mass, they 

 will lie at different distances from the centre of the cylinder; so that, 

 when twisted together, as all the yarns must form spirals of the same 

 number of turns, those which are near the outside, forming spirals of 

 large diameter, will be stretched to their full extent ; while those near 

 the centre, forming spirals of smaller diameter, will be less shortened 

 by the process of twisting, and must therefore be more or less 

 puckered up, according to their proximity to the centre of the mass. 

 The first successful attempt to remedy this defect by varying the 

 length of the yarns according to their position in the strand, was 

 that under Captain Huddart's patent of 1793 ; since which time many 

 further improvements have been effected in this essential point. 



This brings us to notice briefly the application of machinery to rope- 

 making, which may be said to have begun about the year 1783, and 

 to have been the subject of numerous ingenious inventions since that 

 date. One series of machines relates to the combining of the hempen 

 fibres into yarns ; another to the twisting of yarns into ropes ; while 

 the more complex kinds include both of these actions. Mr. Lang, of 

 Greenock, was the first to produce successfully machine-spun yarns, 

 intended to get rid of the irregularities and defects of those formed by 

 hand. By his process the hemp is more completely heckled, or divided 

 into fibres, than in the common mode of proceeding; and the 

 advantage of each fibre being laid at full length in the yarn, instead of 

 being doubled, as in hand-spinning, is ensured. By a modification of 

 the usual process, the fibres of hand-spun yarns may be laid in at full 

 length, instead of being doubled, as when they enter the yarn by their 

 bight ; but experiment has not shown any great advantage from such 

 a mode of spinning. That some improvement in this operation was 

 needful, may be inferred from the result of a comparison between Mr. 

 Lang's machine-spun yarns and those of equal grist spun by hand ; 

 the result showing the strength of the former to exceed the latter by 

 fifty-five per cent. Mr. Sherman, of Liverpool, patented a method of 

 rope-making intended to obviate the necessity for a long shed or rope- 

 walk. The machinery comprises rotating tables with hollow shafts or 

 axes; spindles project from the surfaces of the tables; bobbins are. 

 mounted on the spindles ; and hemp is wound on the bobbins. The 

 number of bobbins depends on the number of yarns and strands. The 

 ends of the yarns are passed through holes in a draw-plate beyond the 

 hollow shaft of one table, then through the hollow shaft, then through 

 another shaft ; and so on. The yam from each bobbin thus becomes 

 twisted round that of the other bobbins on the same table ; then round 

 the similarly twisted strands of another series ; and then of a third. 

 The finished strand or rope is drawn from the tube of the last 

 table, and is wound upon a reel ready for use. A modification of this 

 planetary system, as the inventor calls it, suffices for twisting the 

 strands into a rope. 



Captain Huddart's rope-making machinery, above adverted to, is 

 very ingenious. In order to get rid of the unequal strain upon the 

 exterior and interior of a rope, Huddart saw that the outer yarns of 

 every strand ought to be somewhat longer than the inner, to com- 

 pensate for the greater circumference round which they have to turn. 

 This he accomplished in a beautiful way. Bobbins are arranged in a 

 skeleton frame, each poised on a pivot and loaded with yarn ; the 

 number of bobbins depends on the thickness of the strands to be 

 made. The ends of all the yarns are passed through an equal number 

 of small holes in a plate, and combined into one close group, which is 

 slightly compressed by passing through a tube, and then wound on a 

 reel. The mechanism between the plate and the reel rotates on a 

 horizontal axis, thereby imparting a twist to the assemblage of yarns. 

 The free rotation of the bobbins, the arrangement of the holes in the 

 plate, the position of the tube, and the velocity of revolution all 

 combine to produce a strand of any desired hardness of twist, without 

 undue strain upon any of the yarns. The strand thus produced is a 

 smooth uniform piece of cordage, varying in thickness according to the 

 size of the rope to be made ; for a 12-inch cable, the strand is about an 

 inch thick and contains 80 yarns. Being worked by steam power and 

 having facilities for renewing the bobbins as they are exhausted, this 

 machine can produce a rope any length. 



