464 



R O P E M A K I N G. 



Hope. <3 that by applying wheels of a greater or lesser num- 



^inaking. ^er o f teeth above and beneath, the twist given to the 



""~ / ""'" ' strands can be increased or diminished accordingly. 



The upper of these two communicates motion by means 



of the shaft o, to another spur wheel 8, which, work- 



jng in the three pinions (9) above, gives the twist to 



the strand hooks. 



The carriage is drawn out in the following manner. 

 *g- 3. Q n t j, e en( j O f t h e s | )a f t 2.2 (Fig. 8.) is the pinion r, 

 which, working in the large wheel R, gives motion to 

 the ground rope-shaft s s. In the centre of this shaft 

 is a curved pulley or drum t, round which the ground 

 rope takes one turn. This rope is fixed at the head 

 and foot of the ropery, so that when the machinery of 

 the carriage is set a-going by .the endless rope k k, and 

 gives motion to the ground rope-shaft as above de- 

 scribed, the carriage will necessarily move along the 

 railway, and the speed may be regulated either by the 

 diameter of the circle formed by the gubs on the wheel 

 in m, or by the number of teeth in the pinion r. 

 (Fig. 3.) T is a small roller merely for preventing the 

 ground rope from coming up among the machinery. 

 At the head of the rail-way, and under the tackle- 

 board, (Fig. 2.) is a wheel and pinion Z, with a crank 

 for tightening the ground rope. (Fig. 2. connected 

 y>g- 8. with Fig. 8.) exhibits the fixed machinery at the head 

 for hardening or tempering the strands. The machi- 

 nery here is similar to that on the carriage, with the 

 exception of the ground rope gear which is unneces- 

 sary. The motion is communicated by another end- 

 less rope,, (or short band as it is called, to distinguish 

 it from the other,) and passing over gubs at the back 

 of the wheel 1.1. 



When the strands are drawn out by the carriage to 

 the requisite length, the spur wheels r R, (Fig. 3.) 

 are put out of gear. The strands are cut at the tackle- 

 board and fixed to the hooks 1, 1, 1 ; after which they 

 are hardened OF tempered, being twisted at both ends. 

 When this operation is finished, the three are united 

 on the large hook h, the top put in, and the rope finish- 

 ed in the usual way. 



In preparing the hemp for spinning an ordinary 

 thread of rope yarn, it is only heckled over a large 

 keg or clearer, until the fibres are straighted and 

 .separated so as to run freely in the spinning. In 

 this case the hemp is not freed of the tow or cropt, 

 unless it is designed to spin beneath the usual grist, 

 which is about twenty yarns for the strand of a three 

 inch strap-laid rope. The spinning is still performed 

 by hand, being found not only more economical, 

 but also to make a firmer and smoother thread than 

 has yet been effected by machinery. Various ways 

 have been tried of preparing the yarns for tarring. That 

 which seems now to be most generally in use, is to 

 warp the yarns upon the stretch as they are spun. This 

 .is accomplished by having a wheel at the foot as well 

 as the head of the walk, so that the men are able to 

 spin both up ami down, and also to splice their threads 

 at both ends. By this means they are formed into a 

 haul resembling the warp of a common web, and a little 

 turn is hove into the haul to preserve it from getting 

 foul in the tarring. The advantages of warping from 

 the spinners as above, instead of winding on wenches, as 

 formerly, are, 1st, the saving of this last operation altoge- 

 ther ; 2dly, the complete check which the foreman has 

 of the quantity of yarn spun in the day; and 3dly A that 

 :the quality of the work can be subjected to the minutest 

 inspection at any time. In taring the yarn, it is found 

 ^favourable to the fairness pf the strip, to allow it to 



pass around or under a reel or roller in the bottom of Rope. 

 the kettle while boiling, instead of coiling the yarn in making. 

 by hand. The tar is then so pressed from the yarn by * m ^-f m 

 means of a sliding, nipper, with a lever over the upper 

 part, and to the end of which the necessary weight 13 

 suspended. The usual proportion of tar in ordinary 

 ropes is something less than a fifth. In large strap- 

 laid ropes, which are necessarily subjected to a greater 

 press in the laying of them, the quantity of tar cau 

 scarcely exceed a sixth, without injuring the appearance 

 of the rope when laid. 



For a long pe-riod the manner of laying the yarns 

 into ropes, was by stretching the haul on the rope- 

 ground, parting the number of yarns required for each 

 strand, and twisting the strands at both ends by means 

 of hand-hooks or cranks. It will be obvious that this 

 method, especially in ropes of any considerable size, is 

 attended with serious disadvantages. The strand must 

 ever be very uneven j but the principal disadvan- 

 tage, and that which gave rise to the many attempts at 

 improvement, was, that the yarns being ail the same 

 lengtti before being twisted, it followed when the rope 

 was finished, that while those which occupied the cir- 

 cumference of the strand, were perfectly tight, the 

 centre yarns on the other hand, as they were now great- 

 ly slackened by the operation of hardening or twisting 

 the strands, actually would bear little or no part of the 

 strain when the rope was stretched, until the former 

 gave way. The method displayed in the accompany- 

 ing drawing and description is among the latest and 

 most approved. Every yarn is given out from the 

 bobbin frame as it is required in twisting the rope ; and 

 the twist communicated in the outgoing of the carriage, 

 can be increased or diminished at pleasure. In order 

 to obtain a smooth and well. filled strand, it is necessary, 

 also, in passing the yarns through the nipper board, to 

 proportion the number of centre and outside yarns. 

 We know of no arithmetical proportion for ropes 

 of all sizes ; but in ordinary sized ropes, the strand 

 seems to have the fairest appearance when the outside 

 yarns form from Ids to f ths of the whole quantity in the 

 strand. But the nicest part of the operation is the pro-! 

 portion of twist given by the carriage in drawing out 

 and forming the strand?. Were the whole twist neces- 

 sary, communicated then, and the rope closed without 

 the operation of hardening, the whole strain would beat- 

 on the centre yarns when the rope came to be stretch- 

 ed. The object of hardening (that is twisting the 

 strands at both ends before putting in the top to close 

 the rope), seems to be, at once to tighten &ndjirm the 

 strand, and also so to ease the centre yarns, as that too 

 much strain may not fall upon them either in closing 

 or afterwards in stretching the rope. We find the twist 

 to be in this proportion when one complete turn of an 

 outside yarn occupies as much space along the strand 

 as the circutTii'erence of the rope itself when made. 

 This is easily seen by attaching a white thread to an 

 outside yarn before it reaches the nipper. It may be 

 also ascertained by the difference of length between the 

 centre and an outside yarn, taken in connexion with 

 the circumference of the rope; but the former method 

 is the simplest and most satisfactory. It may be remark- 

 ed also, that this refers to strap-laid ropes only. In hawser, 

 or cant-laid ropes, as they are called, the proportion of . 

 twist is fully ^th less. Where this is not attended to, 

 the hawser, or cable, will be found to be stiff and un- 

 manageable. However, it is difficult to give precise 

 arithmetical proportions. The ropemaker should have 

 frequent recourse to experiment, that is, to the exami- 

 6 



