ROPE-MAKING. 



In laying cordage, the yarn for twitting into ftrands is 

 hung on the hooks in the tackle-board, at the upper end of 

 the ground, and upon hooks in the brealt-board of the 

 fledge, at the lower end, which are turned by men at both 

 ends until the itrands are hard ; and are kept up from the 

 ground by the (take-heads. 



Before the turn is put in, the yarn (hould be ftretched to 

 its full extent by means of the tackle fixed from the fledge 

 to the capftern, at twenty yards afunder, at the lower end of 

 the ground ; and when itretched to two hundred fathoms, 

 the prefs is put upon the fledge and drag, before the tackle- 

 fall is ca(t off; for if the yarn be not properly ftretched be- 

 fore the tackle-fall is caft off, the rope will not be of its fize, 

 nor well made. 



The ftrands fliould have a good hardening before the top 

 is put in to lay the rope, and the layer fliould fee that the 

 heavers at the upper end keep the fame hardnefs that the 

 rtra.ids had before the top fet off, nor fliould he begin to lay 

 the rope until the fledge or wheel is moved by the power of 

 the twift from the upper end. 



When twifted fuffieicntly hard, the ftrands are hung on 

 one hook in the brealt-board of the fledge, but remain fe- 

 paratc on th:- three hooks at the other end. The top is 

 placed in at the fledge, and the rope t wilted by turning the 

 hooks at both ends one way, and, as the rope clofes, the 

 top moves towards the upper end. 



When the top is put in, fome of the weight fliould be 

 taken off the fledge or drag, for if laid with as much weight 

 as is ufed in the hardening, it would be too (tiff, but, by re- 

 moving a part of the weight, the ftrands will couch better. 



The ftrength of the men at the hooks being greatly inade- 

 quate to the force required for twiiting of cables, woolders 

 are uied, according to the fize of the cable, at equal diftances 

 along the whole length. 



Cables fliould be rounded by the lower hook after they are 

 laid, to throw the turn well up. They are generally thought 

 to wear belt when flack-laid ; but fome think when fhort- 

 laid. 



Cablets ufed for tow-lines or hawfers, require the ftrands 

 to be laid (horter than cable-ftrands, but not fo (hort-laid in 

 clofing ; for being ufed in water, they would become (tiff, 

 hard, unhandy to coil away, and liable to break in cold 

 weather. 



In all cable-laid ropes, the proportion of the circum- 

 ference is to the length of the ftrand in one round, as 1 1 is 

 to 15; that is, if the circumference be 14 \ inches, the 

 length of the ftrand in one circumference is 19; inches. In 

 all hawfer-laid rope, the proportion is as 1 2 to 16; that is, 

 if the circumference be 7 inches, the length of the ftrand in 

 one circumference is near 9^. 



The ftrength of ropes depends on the hardening or well 

 manufacturing, and not on the bare ftrength of the hemp ; 

 for it ltrengthens through every ftage ; viz. when firit fpun 

 into yarn it is little better than hemp extended ; when 



twifted into ftrands, it fhortens and ftrengthens as above, 

 and increafes in the fame manner when laid into rope. 



Where the diameter and circumference of one rope to an- 

 other is as two to one, that is, where one rope is twice as 

 big as another, the fquare of the diameter is as four to one • 

 which (hews, that one rope has four times as much yarn in 

 it as the other, and confequently is four times as ftrong, 

 according to the different magnitudes. 



Cable-laid ropes (liorten as five to three, and hawfer-laid 

 ropes as three to two ; confequently the length of the yarn 

 and ftrength will be accordingly ; that is, the ftrength will 

 be in the yarn, after it is laid in the rope, as much as if the 

 rope-maker, in fpinning, had allowed the fame quantity of 

 hemp in two feet as he did in three feet, fo that the ftrength 

 communicated by the procefs is two-thirds. 



A rope is the fame fize when laid as the yarns were before 

 twifted ; fo that what the yarns are leffened by twiiting it is 

 made up by (hortening ; from which it is inferred, that the 

 yarns are always of an equal bignefs, fince the hemp is the 

 fame at one time as at another, and not any way diminilhcd. 

 Were the ftrands fingle, without being twifted one about 

 another, the ftrength would then be only in proportion as 

 the area of each particular ftrand is in itfelf ; but if the 

 ftrands could poflibly be twifted fo as to be dire&ly perpen- 

 dicular to the bafe, the ftrength would then be found, by- 

 multiplying the diameter of the ftrands and the diameter of 

 the whole rope one into the other, and the half of the pro- 

 duct would be the ftrength of the faid Itrands ; but more 

 particularly take the area of the fingle ftrand and area of the 

 whole cable, and add them together, and the half of that 

 will (hew the ftrength of each ftrand when they are well 

 twifted together. 



But as it may be obfervcd the ftrands lie at a certain angle 

 between a perpendicular and the bafe, fo that, as the angle 

 of incidence is to radius, fo is the relative to the abfolute 

 ftrength. 



Refpedting the Banding of Cordage. — In the calculations 

 fpecifying the weights of the different lengths of cordage, 

 fuch weights are to beconfidered as the neat weights of the 

 rope without bandage. 



N. B. To every hundred weight of cordage the manu- 

 facturer is allowed to put on four pounds weight of bands ; 

 thofe bands are compofed of the fhakings, flyings, and 

 firings with which the hemp is tied together, formed into an 

 interior kind of cordage ; but it is to be obferved thofe are 

 all weighed to the rope-makers as good hemp, and paid for 

 accordingly, therefore if he was not allowed to apply the 

 refufe to fuch purpofe, he mult either put a higher price on 

 his cordage, or be a very confiderable lofer. At the fame 

 time it (hould be confidered, that as it is neceflary that every 

 coil of rope (hould be bound together for the convenience of 

 carriage, (towage, &c. this kind of bandage anfwera 

 luch purpofe in every degree, as well as if the coils were 

 bound with bands made from the beft hemp. 



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