None
5 .2 •J3 18.1 .24 .2 •55 44 20 •79 .072 6-57 1.82 717 7-5 •3 .22 16 •3 •3 .68 99 25 .98 .O8l 5-97 2.01 I 142 IO •39 •31 14.1 •38 •39 .88 178 30 1.18 •093 5-4 2.22 1635 12.5 •49 •39 12.7 •44 •49 .04 277 35 1.38 .1 4-93 2.41 22l8 15 •59 .4811.5 •52 •59 .2 400 40 J-57 .106 4-53 2.63 2912 17.5 .69 .58 10.6 .58 .69 •4 545 45 1.77 .II4 4.2 2.85 3074 20 •79 .66 9.8 .66 •79 •5 7i3 50 1.97 .128 3-9i 3-07 4547 22.5 .89 .76 9.1 .72 .89 .68 902 55 2.17 •13 3-65 3-3 5288 25 .98 .84 8.5 .8 .08 .84 I 120 00 2.36 .14 343 3-5 6540 30 1.18 i. 02 7-5 94 1.18 2.16 1035 65 2.56 •15 3-23 3-7 7660 35 1.38 12 6.7 i. 08 1.38 2.48 22l8 70 2.76 .158 3-o6 3-92 8893 40 1.58 1.4 6 .22 158 2.8 2912 75 2-95 .166 2.92 4-13 10214 45 1.77 1-56, 5-5 .36 1.77 3-2 3674 80 3-15 .174 2.76 4-36 11603 50 1.97 i-74 5-i •5 1.97 3-44 4547 85 3-35 .183 2.63 4.58 13100 55 2.17 1.92 4.7 .64 2.17 3-76 5288 90 3-54 .192 2.51 4.78 14794 60 2.36 2.08, 4.4 •74 2.36 4.08 6540 95 3-74 .2 2.41 5 16352 65 2.56 2.26 4.1 .92 2.56 4.4 7660 100 3-94 .209 2.31 5.22 18144 70 2.76 2.44' 3-8 2.06 2.76 4-7 8893 105 4-i3 .22 2.22 5-43 20000 75 295 2-6 | 35 2.2 2-95 5 10214 no 4-33 .226 2.13 5-66 21950 80 3-15 2.78, 3-4 2-34 3-15 5-35 11468 "5 4-53 •23 2.O6 5-87 23990 English. Bolts and iNTuts. (WUtworWs.) Hexagonal Heads arid. N"nts, and Triangular Threads. Diame Bolt. ter. •s-i II l"i ei D Head. sptb. Nut. Width of Head and Nut. Diana Bolt. eter. Base of Thread. Threads per Inch. DeF Head. th. Nut. Width  1.25 1.067 7 1.094 1.25 2.048 .1875 •134 24 .164 •1875 .448 1-375 1.161 6 1.203 1-375 2.215 .2187 24 i-5 1.286 6 1.312 1.5 2.413 •25 .186 20 .219 •25 •525 1.625 1.369 5 1.422 1.625 2.576 •3I25 .241 18 •273 •3125 .001 i-75 1.494 5 L53I i-75 2.758 •375 .295 16 .328 •375 .709 1-875 !-59 4-5 1.641 1-875 3.018 •4375 •346 14 •383 •4375 .82 2 I-7I5 4-5 i-75 2 3-T49 •5 •393 12 •437 •5 .919 2.125 1.84 4-5 1.859 2.125 3-337 •5625 •456 12 .492 •5625 .Oil 2.25 i-93 4 1.969 2.25 3-546 .625 .508 II •547 .625 .101 2-375 2.055 4 2.078 2-375 3-75 .6875 •571 II .60! .6875 .201 2-5 2.18 4 2.187 2-5 3.894 •75 .622 10 .656 •75 .301 2.625 2.305 4 2.297 2.625 4.049 .8125 .684 10 .711 .8125 •39 2-75 2.384 3-5 2.406 2-75 4.181 •8/5 •733 9 .766 •875 •479 2.875 2.509 3-5 2.516 2.875 4.346 •9375 •795 9 .82 •9375 •574 3 2.634 3-5 2.625 3 4-531 i .84 8 •875 i .67 3-25 2.84 3-25 — — 1,125 •942 7 .984 1.125 .86 3-5 3-o6 3-25 — — — RETENTION OF SPIKES AND NAILS. Square Heads and l^uts. ( Whitwortk* s. ) 159 Dia Bolt. meter. Base of Thread. Threads per Inch. Dia Bolt. meter. Base of Thread. Threads per Inch. Dia Bolt. meter. Base of Thread. Threads, per Inch. Ins. 3-75 4 4-25 Ins. 3-25 3-5 3-75 No. 3 3 2-875 Ins. 4-5 4-75 5 Ins. 3.875 4.0625 4-25 No. 2.875 2-75 2-75 Ins. 5-25 5-5 6 Ins. 4-4375 4.625 4.875 No. 2.625 2.625 2-5 "Weight of* Heads and Nuts in. Lt>s. (Molesworth.) Hexagonal, 1.07 D3. Square, 1.35 D3. D representing diameter of bolt in inches. Retentiveness of 'Wrought Iron Spikes and. Nails. Deduced from Experiments of Johnson and Sevan. SPIKES. SFIKI. WOOD. 1 | Depth of Insertion. Force re- auired to raw it. Ratio of force to weight. REMARKS. Ins. Ins. Ins. Lbs. Square Hemlockf Chestnut •39 •37 •38 3-5 3-5 1297 1873 2.16 Seasoned in part. Unseasoned. " * .... " * .... Yellow pine •375 •375 3-375 2052 2-37 Seasoned. i r*f? ' * .... White oak •375 •375 3-375 3910 4-52 0 u Locust •4 •4 3.5 5967 6.33 ii ef^' Flat narrow.. Chestnut •39 •25 3-5 2223 3-93 Unseasoned. « it White oak •39 •25 3-5 3990 7-05 Seasoned. (t U Locust •39 •25 3-5 5673 9-32 " " broad .. Chestnut •539 .288 3-5 2394 2.66 Unseasoned. u u White oak •539 .288 3-5 5330 5.71 Seasoned. U U Locust •539 .288 3-5 7040 7.84 u Square} ^ • Hemlockf •4 •39 3-5 1638 Seasoned in part. " >• 2,2 Chestnutf -4 •39 3-5 1790 i.Si Unseasoned. " J Q « Locust f •4 •39 3-5 3990 4.17 Seasoned in part. Round and) grooved..) Ash Diam. .5 3-5 2052 2.21 Seasoned. M M " -5 3-5 245 * 2.41 u M White oak « .48 3-5 3876 3-2 u * Burden's patent. t Soaked in water after the spikes were driven. NAIL. Length. Depth of Insertion. Pine. NAILS Force r& Hemlock. ;. quired to Elm. draw it. Oak. Beech. Pressure required to force them into Pine. Sixpenny u Ins. 2 2 2 Ins. I 1-5 2 Lba. I87 327 530 Lbs. 3I2 539 857 Lbs. 327 571 899 Lbs. 507 675 1394 Lbs. 667 889 1834 Lbs. 235 4OO 610 General Remarks. With a given breadth of face, a decrease of depth will increase retention. In soft woods, a blunt-pointed spike forces the fibres downwards and backwards so as to leave the fibres longitudinally in contact with the faces of the spike. l6<D ANGLES AND DISTANCES. — DISTANCES AND ANGLES. To obtain greatest effect, fibres of the wood should press faces of the spike in direction of their length ; thus, a round blunt bolt, driven into a hole of a less diameter, has a retention equal to that of any other form, when wholly driven, as without boring. The retention of a spike, whether square or flat, in unseasoned chestnut, from two to four inches in length of insertion, is about 800 Ibs. per square inch of the two surfaces which laterally compress the faces of the spike. When wood was soaked in water, after spikes were driven, order of their retentive power was Locust, White oak, Chestnut, Hemlock, and Yellow Pine. Diameter in Inches.. Threads per Inch . .. G-as IPipe Threads. .125 I .25 I .375 I .5 .75 i 28 I 19 I 19 | 14 14 1.25 ii 2 II ANGLES AND DISTANCES. Angles and Distances corresponding  73 14.28 a .42 20 4.17 38 7.8l 56 11.27 74 14.44 3 .63 21 4-37 39 8.01 57 "•45 75 14.61 4 .84 22 4.58 40 8.2 58 11.64 76 14.78 5 1.05 23 4.78 41 8.4 59 11.82 77 14.94 6 1.26 24 4-99 42 8.6 60 12 78 15.11 7 1.47 25 43 8.8 61 12. l8 79 I5-27 8 1.67 26 5-4 44 8-99 62 12.36 80 15.43 9 1.88 27 5-6 45 9.18 63 12.54 81 J5-59 10 2.09 28 5.81 46 9-38 64 12.72 82 ii 2.3 29 6.01 47 9-57 65 12-9 83 15-9 12 2.51 30 6.21 48 9.76 66 1307 84 16.06 13 2.72 31 6.41 49 9-95 67 I3-25 85 16.21 14 2.92 32 6.62 50 10.14 68 13,42 86 16.37 15 33 6.82 51 10.33 69 13-59 87 16.52 16 3-34 34 7.02 52 10.52 70 13-77 88 16.67 17 3-55 35 7.22 53 10.71 71 13.94 89 16.82 18 3-75 36 7.42 54 10.9 72 14.11 90 16.97 Distances and A.ngles corresponding to Opening of a Rnle of Two Feet. Distance Angle. Distance. Angle. Distance. Angle. Distance. Angle. Distance Angle. Ins. o Ins. 0 Ins. 0 Ins. 0 Ins. o •25 1. 12 3 14.22 6-5 31.26 10 49.14 13-5 68.28 •375 1.48 3-25 15-34 6-75 32-4 10.25 50-34 13-75 69-54 •5 2.24 3-5 16.46 7 33-54 10-5 51-54 14 71.22 .625 2-59 3-75 I7-58 7-25 35-09 10-75 53-14 14.25 •75 3-35 4 19.11 7-5 36.24 II 54-34 14-5 74-2 •875 4.12 4-25 20.24 7-75 37-4 11.25 55-54 I4-75 75-5 £ 4-48 4-5 21.37 8 38-56 "•5 15 77.22 1.25 5-58 4-75 22.5 8.25 40.12 "•75 5^38 15-25 78.54 *-5 7-1 5 24.4 8-5 41.28 12 60 15.5 80.28 I-75 8.<22 5-25 25.16 8-75 42.46 12.25 61.23 82.2 2 9-34 5-5 26.3 9 44.2 12.5 62.46 16 83-36 2.25 10.46 5-75 27-44 9-25 45-2 1275 64.1 16.25 85-14 2-5 11-58 6 28.58 95 46.38 65.36 16.5 1 86.52 2-75 13.1 6.25 30-12 9-75 47-56 '3-25 67.02 16.75 [88.32 WIRE ROPE. 1 6 1 WIRE ROPE. Wire rope will run over sheavee of like diameter to Hemp rope of same strength ; but larger sheaves reduce wear. Adhesion is the same as that of hemp rope. Wear increases rapidly with speed. Short bends should be avoided. In substituting wire rope for hemp, allow same weight per foot. Kinking wire rope materially damages and often destroys it. For transmission of power, wire rope can be used up to distances of 3 miles. For distances less than 100 feet, it is not advised for long trans- mission; sheaves are placed at intervals, dividing it into a number of shorter ones of 250 to 300 feet. Strength per square inch of section of rope is about 50 per cent, of an equal section of solid metal of §ame strength per square inch. Stationary wire ropes should be kept well painted or tarred to prevent their oxidation. Running ropes should always be well lubricated and pro- tected from grit with linseed-oil, pine tar, graphite grease, or any similar non-acid substances. Standard wire rope is made of 6 strands of 7, 12, or 19 wires each, with hemp or wire centre. Wire centre adds 10 per cent, to strength and weight of rope, but reduces its flexibility proportionally. Safe working load for standing ropes is about one fourth ultimate strength, arid for running ropes it is from one fifth to one seventh. Ropes for hoisting are composed of 6 strands of 19 wires each around a hemp centre. Ropes for transmission of power, for guys and rigging, are composed of 6 strands of 7 or 12 wires each. The ultimate strength of wires of which wire ropes are made are for : Iron wire, 70000 to 90000 Ibs. per sq. inch; Bessemer steel wire, 100000 to iioooo Ibs.; Crucible cast -steel wire, 150000 to 180000 Ibs., and Special plough-steel wire, 210000 to 300000 Ibs. Special ropes can be made of 4, 6, 8, etc., strands of varied construction. Wire ropes are also made flat, composed of several strands alternately twisted to right and left, laid alongside each other, and sewed together with soft iron wire. Wire hawsers of steel are made of 6 strands of 12 wires each with hemp centre, around a common hemp centre, and are as flexible as hemp hawsers of equal strength. Galvanized wire rope replaces hemp for rigging, because of its cheapness, durability, and resistance to stretch. It is one fifth bulk for equal strength of hemp "rope, and offers less surface to wind. Tiller ropes for vessel-steering gear are made of 6 smaller ropes around a hemp centre, each small rope composed of 6 strands of 7 wires each with hemp centre — 252 wires in all in the rope, giving great flexibility. Yacht rigging of galvanized cast-steel rope is one third to one half weight of iron wire rope of equal strength. 162 WIRE ROPES. Elements of Hoisting and Haulage TVire Rope. John A. Roebling's Sons Co. , Trenton, N. J. HOISTING ROPE. 19 Wires in a Strand. Hemp Centre. SWEDISH IRON. CAST-STKEL. Diameter. Approx- imate Circum- ference. Weight Foot. Tons of 2000 Lbs. Breaking Safe Strain. Strain. Least Diameter of Drum or Sheave. Tons of 2 Breaking Strain. ooo Lbs. Safe Strain. Least Diameter of Drum or Sheave. Ins. lus. Lbs. No. N 0 Feet. No. No. Feet. 2.25 7-125 8 78 15 .6 i 3 156 31.2 8-5 2 6.25 6-3 [ 62 12 •4 i 2 24.8 8 1.75 5-5 4-85 48 9 .6 10 96 19.2 7-25 1.625 5 4-15 42 8 •4 8-5 84 16.8 6.25 1-5 4-75 3-5 ) 36 7 .2 7-5 72 14.4 5-75 1-375 4-25 3 3' 6 .2 7 62 12.4 5-5 1-25 4 2-4. ) 25 5 6-5 50 10 5 1.125 3-5 2 21 4 .2 6 42 8.4 4-5 i 3 1-5* 5 17 3 •4 5-25 34 6.8 4 .875 2-75 1.2 13 2 .6 4-5 26 S-2 3-5 •75 2.25 •8c ) 9- 7 X •94 4 19.4 3-88 3 .625 2 .62 6. 8 I .36 3-5 13.6 2.72 2.25 •5625 1.75 •5 5- 5 I . i 2-75 ii 2.2 •5 1.5 ) 4- 4 .88 2.25 8.8 X.76 J-5 •4375 1.25 • 3' 3- 4 .68 2 6.8 1.36 '•25 •375 1. 12 5 .25 2. 5 •5 1.5 5 I i •3125 I .1; I. 7 •34 I 3-4 .68 .667 •25 •75 .1 I. 2 .24 •75 2.4 .48 • 5 '.Transmission and Haulage Rope. 7 Wires in a Sti 'and. h emp Cer itre. No rn.— Add 10 per cent, to weight for WIRE CENTRE. Swi DISH IRON. CAST-STKEL. Diameter. Approx- imate Circum- ference. Weight per Foot. Tons of 2 Breaking Strain. ooo Lbs. Safe Strain. Least Diameter of Drum or Sheave. Tons of 2 Breaking Strain. ooo Lbs. Safe Strain. Least Diameter of Drum or Sheave. Ins. Ins. Lbs. No. No. Feet. No. No. Feet. •5 4-75 3-55 34 6.8 13 68 13-6 8.5 •375 4-25 3 29 5- S 12 58 ii. 6 8 •25 4 2-45 24 4.8 10.75 48 9.6 7-25 .125 3-5 2 20 4 9 -5 40 8 6.25 3 1.58 16 3- 2 8-5 32 6.4 5-75 '.875 2-75 1.2 12 2. 4 7 • 5 24 4.8 5 •75 2.25 .85 9- 3 I. 86 6 •75 18.6 3-72 4-5 .6875 2.125 •75 7- 9 I.58 6 15-8 3.16 4 .625 2 .62 6. 6 I. 32 5 •25 13.2 2.64 3-5 -5625 1.75 •5 5- 3 I .06 4 -5 10.6 2.12 3 • 5 1.5 •3S 4- 2. 84 4 8.4 1.68 2-5 •4375 1.25 • 3 3' 3 .66 3 •25 6.6 1.32 2.25 •375 I.I25 .22 2. 4 .48 2-75 4.8 .96 2 •3125 I .15 I. 7 34 2 -5 3-4 .68 !-75 .2813 .875 .125 I. 4 28 2 -25 2.8 •56 Galvanized Charcoal Iron. "Wire Rope. Vessels' Rigging a lid .Derrick GJ-viys. 7 or 12 Wire 5 in a Strand. Hemp Centre. Approx- imate Diam- eter. 3ircum- erence. Weight per Foot. Breaking Strain in Tons of 2000 Lbs. of Maniltt Rope of Equal Strength Approx- imate Diam- eter. Circum- **% ference. jf^ Breaking Strain in Tons Of 2OOO Lbs. Circum. >f Manila Rope of Equal Strength. Ins. Ins. Lbs. No. Ins. Ins. Ins. Lbs. No. Ins. •75 5-5 4-85 44 ii •25 4 2.55 23 8 .6875 5-25 4-4 40 10.5 •1875 3-75 2.25 20 7-5 .625 5 4 36 10 .125 3-5 i-95 18 6.5 •5 4-75 3-6 32 9-5 .0625 3-^5 i-7 15 6 •4375 4-5 3-25 29 9 3 i-44 13 5-75 •375 4-25 2.9 26 8-5 '-875 2.75 i. 21 II 5-25 WIRE ROPES, HAWSERS, AND CABLES. i63 Gralvanized Charcoal Iron "Wire Rope. Vessels' Rigging and Derriclz Griiys. John A. Roebling'ls Sons C"o., Trenton, N. J. 7 Wires in a Strand. Approx- imate Diam- eter. Circum- ference. Weight Fwt. Breaking Strain in Tons of POOO Lbs. Circum. of Manila Rope of Equal Strength. Approx- imate Diam- eter. Circum- ference. Weight Breaking Strain in Tons Of 2080 Lbs. Circum. ofManila Rope of Equal Strength. Ins. Ins. Lbs. No. Ins. Ins. Ins. Lbs. No. Ins. .8125 2.5 i 9 5 •375 1.125 .2 1.8 2.25 •75 2.25 .81 7«3 4-75 •3125 i .16 1.4 2 .625 2 .64 5.8 4-5 .2812 .875 .123 i.i I-75 •5625 1.75 4.4 3-75 .25 .81 1-5 .5 1.5 •36 3-2 3 .2188 .625 .063 •56 1.25 •4375 1.25 .25 2-3 2.5 •1875 • 5 .04 •36 1.125 Gralvanized. Steel Hawsers. For Sea and. Lalze T<ywing. Approx- imate Diam- Circum- ference. Weight Foot. breaking Strain in Tons of 2000 Circnm. of Manila Rope of Equal Approx- imate Diam- Circum- ference. Weight t>er Foot. Breaking Strain in Tons Of 2000 Circum. ofManila Rope of Equal eter. Lbs. Strength. eter. Lbs. Strength. Ins. Ins. Lbs. No. Ins. Ins. Ins. Lbs No. Ins. 1-75 5-5 3.25 61 13-5 I-4375 4-5 2.1 3 42 "•5 1.6875 5.25 2-95 57 13 1.375 4.25 1.94 39 ii 1.625 5 2.7 53 12.5 i •25 4 1-7 2 32 10 1-5 4-75 2.42 45 12 1.1875 3-75 1.5 29 9.25 GJ-alvanized Steel Cables for Suspension Bridges. Diam- Weight Breaking Strain in Diam- Weight Breaking Stra n in Diam- Weight Breaking Strain in eter. Foot. Tons of 2000 eter Lbs. BE Tons of 2000 eter Lbs. Ct. Tons of 2000 Lbs. Ins. Lbs. No. Ins. Lbs. No. Ins. Lbs. No 2-75 12.7 3»o 2.375 9-5 232 2 6-73 164 2.625 n. 6 283 2.25 8.52 208 I .875 5-9 144 2-5 10.5 256 2.125 7-6 185 I •75 5-' 124 Grange, Weight, and Length of Iron "Wire. 1 Diam. Weight per loo Feet. Weight of one Mile. 63 Ibs. Bundle. Area. 1 I ' 1 > Diam. Weight per 100 Feet Weight of one Mile. 63 Ibs. Bundle. Area. N Inch. Lbs. Lbs. Feet. Sq. Inch. NoT Inch. Lbs Lbs. Feet. Sq. Inch. 6/0 .46 56.1 2962 112 .16619 16 .063 1.05 55 6000 . 003 117 5/o •43 49.01 2588 129 .14522 I .054 •77 41 8182 .00229 4/0 •393 40.94 2162 154 .1 21304 I 8 .04 7 -58 31 10 362 .001734 3/o .362 34-73 1834 .102921 I .041 •45 24 14000 .00132 2/0 •331 29.04 1533 217 . 086 049 20 •035 •32 17 19687 .000962 I/O •3°7 27.66 1460 228 .0 74023 2 i -03 2 .27 14 23 333 .000804 i .283 21.23 II2I 296 .062901 22 .028 .21 ii 30000 .000615 2 .263 18.34 968 343 .0 54325 2 3 .02 5 •17 5 9.: '4 36 DOO .000491 3 .244 I5-78 833 399 .046759 24 .023 .14 7-39 45000 .000415 4 .225 13-39 707 470 .03976 25 .02 5 6.124 54310 .000314 5 .207 "•35 599 555 .0 33653 2 5 .OI 8 .09 3 )i 67 742 .000254 6 .192 9-73 647 .0 28952 2 7 .01 7 .08 3 4-: 582 75 ?°3 .000227 7 .177 8.03 439 759 .024605 2 S .Ol6 .074 3-9°7 85135 .000201 8 .162 6.96 367 9°5 .0- 20612 2 9 .01 5 .06 r 3-' 22 103 278 .000 176 9 .148 5.08 306 1086 .017 203 30 .014 •054 2.851 116666 .000154 o •135 4-83 255 1304 •014313 31 •0135 2.64 126000 .000133 i .12 3.82 202 1649 .on 309 32 .013 .046 2.428 136956 .000132 2 .105 2.92 154 2158 .0< 38659 3 3 .01 i •03 7 I. ?53 170 270 .000095 3 .092 2.24 118 2813 .006647 34 .01 •03 1.584 2IOOOO .000078 4 .08 1.69 89 3728 .01 35026 3 5 .oc Q5 .02 5 I. 32 252 000 .000071 5 .072 72 4598 .004071 36 .009 .02 1.161 286363 .000064 164 IKON, STEEL, AND HEMP HOPE. "Weight and. Strength, of Single Strand and Cable laid Fence TV^ire. (F. Morton & Co.} Strands. N, Single Wire of equal Diameter. Len per 10 Of a Strand. gth oo Ibs. Of Rope. Strands. No. Single Wire of equal Diameter. Len per io< Of a Strand. gth DO Ibs. Of Rope. No. No. Inch. Feet. Feet. No. No. Inch. Feet. Feet. 3 2A 8 •159 20090 15270 7 00 4 .229 8300 7366 4 2 7 .174 14730 12790 7 3/o 3 -25 8036 6228 7 I 6 .191 I3I25 10580 7 4/o 2 .274 7500 5156 7 0 5 .209 10446 8928 7 5/o I •3 5090 4286 No. and diameter of wire is that of Ryland's Bros., pp. 122-4. Hemp, Iron, and Steel. (R. S. Newall & Co.) HEMP. Circumference. Weight per Foot. IRON. Circumference. Weight per Foot. STEEL. Circumference. Weight Foot. Tensile 5 Safe Load. >trength. Ultimate Strength. Ins. Lbs. Ins. Lbs. Ins. Lbs. Lbs. Lbs. 2.75 •33 I .16 — — 672 4480 i-5 •25 I .16 1008 6720 3-75 .66 1.625 •33 — — J344 8960 1-75 .42 i-5 •25 1680 II 20O 4-5 .83 1-875 •5 2016 13440 2 •58 1.625 •33 2352 15680 5-5 1.16 2.125 .66 i-75 .42 2688 17920 2.25 •75 — — 3024 20 160 6 i-5 2-375 •83 1-875 •5 336o 22400 2.5 .92 3696 24640 6-5 1.66 2.625 2 •58 4032 26680 2-75 .08 2.125 .66 4368 29 1 20 7 2 2.875 .16 2.25 •75 4704 31360 3 •25 — — 5040 33600 7-5 2-33 3-125 •33 2-375 -83 5376 36840 3-25 .41 — 5672 38080 8 2.66 3-375 -5 2-5 .92 6048 40320 3-5 1.66 2.625 i 6720 44800 8.5 3 3-625 1-83 2-75 i. 08 7392 49280 3-75 2 — 8064 5376o 9-5 3-66 3-875 2.16 3-25 i-33 8736 58 240 10 4-33 4 2-33 9408 62 720 4-25 2-5 3-375 i-5 10080 67200 ii 5 4-375 2.66 — — 10752 71680 4-5 3 3-5 1.66 12096 80640 12 5-66 4-625 3-33 3-75 2 13440 89600 FLAT. Dimensions. Dimensions. Dimensions. 4 X .5 3-33 2.25 X.5 1-85 — 4928 44800 5 Xi.25 4 2.5 X-5 2.l6 — 5824 51520 5-5 Xi. 375 4-33 2.75 X.625 2-5 — 6720 60480 5-75XI.5 4.66 3 X .625 2.66 2 X.5 1.66 7168 62720 6 Xi.5 5 3.25 X.625 3 2.25 x-5 1.83 8064 71680 7 Xi. 875 6 3-5 X.625 3-33 2.25 x. 5 2 8960 80640 8.25X2.125 6.66 3-75 X.6875 3-66 2.5 X-5 2.16 9850 89600 8.5 X2.25 7-5 4 X.6875 4.16 2-75 X. 375 2-5 II 200 100800 9 X2.5 8-33 4-25 X-75 4.66 3 X.375 2.66 12544 II2000 9-5 X 2.375 9.16 4-5 X-75 5-33 3-25 X. 375 3 14336 125 440 10 X2.5 10 1 4.625 X. 75 5-66 3-5 X.375 3-23 15232 134400 HOPES AND CHAINS. 165 Ultimate Strength, arid. Safe Loads of Hemp, Iron, and. Steel. Ultimate SAFB LOAD < | Ultimate SAFE LOAD Strength per Lb. Weight per Foot. perLb. Weight per Foot. per Square in InXT/l Strength perLb.Weigbt per Foot. per Lb. Weight per Foot. per Square ofCircum. in Inches. Lba. Lbs. Lbs. 1 Lbs. Lbs. Lbs. Hemp. Iron . .. 15000 22OOO 4550 5000 100 ! 600 Steel. f 30000 (45500 f6ooo (5000 f 1000 (1300 PLOUGH STEEL FLAT MINING ROPES. John A . Roebling's Sons Co. , New York Width. Thickness. Weight per Foot. Ultimate Strength. Width. Thickness. Weight per Foot. Ultimate Strength. Ins. Ins. Lbs. Lbs. Ins. Ins. Lbs. Lbs. 2 •375 I.I9 63000 5-5 •375 3-9 156000 2-5 •375 1.86 i 74000 5-5 •5 4.8 193000 3 •375 2.32 93000 6 •375 4-34 I73OOO 3-5 •5 2.97 118000 6 •4375 4-5 lOOOOO 4 •375 2.86 114000 6 •5 5-1 210000 4 -5 3.3 130000 6-5 •5 5-5 224000 4-5 •375 3.12 125000 7 •5 5-9 238000 4-5 -1V5 1;I 4 160000 7-5 •5 6.25 250000 5 •375 3-4 125000 8 •5 6-75 270000 sJ$uifri •5 4.27 I7QOOO For Cast- Steel Flat Ropes see page 1029. - Ropes and Chains of Equal Strength. CIRCUMFERENCE. WEIGHT PER FOOT. Diameter of Iron Chain. Hemp Rope. Crucible Steel Rope. Charcoal Iron Rope. Steel Rope. Iron Rope. Hemp Rope. Iron Chain. Safe Load. Ins. Ins. Ins. Ins. Lbs. Lbs. Lbs. Lbs. Tous. •218 75 2-75 — I. 14 •34 «5 -3 •25 3 — 1.18 , 21 .46 •65 •4 .28125 3-5 I 1.39 •17 28 .67 .81 •5 •3125 4-25 1.26 1.57 •25 33 •75 .96 .6 •375 4-5 1.45 1.77 •3 •45 •83 1.38 .8 •4375 5 1.57 1.97 •35 57 1.16 I.76 i .46875 5-5 1.77 2.19 •45 7 1.2 2.2 1.3 •5 5-75 1.06 2.36 •59 -83 1.6 2.63 1.5 -625 6-75 2.36 2-75 •85 i. 08 2 4.21 2-3 .6875 7-75 2-75 3-14 I .1 1-43 2.65 4.83 •75 8-75 2-95 3-53 I .28 1.8 3-35 5-75 3'8 •875 9-75 3.14 3-93 I •45 2-3 4.6 7-5 4.8 •9375 10.5 3-53 4-32 1.83 2-94 4-92 9-33 5-9 1.0625 n-75 3-93 4.71 2-33 3-56 5-83 10.6 7 1.125 12.75 4-32 5.1 2.98 4 6.2 11.9 8.2 1.25 J4-75 4.71 5-5 3-58 4.8 8-7 14-5 9-5 1-375 15-25 4.81 5-89 3-65 5-6 9 17.6 ii 15-75 5.1 6.28 4.04 6.3 10. 1 20 12.5 1.625 17-75 5-8 7.07 5-65 7-95 13-7 22.3 J-75 19-5 6-35 7.85 6-5 9 81 16.4 24-3 19.6 By experiments of U. S. Navy, hemp rope of this circumference has weight of 71 309 Z&s., and a wire rope of 5.34 ins. has equivalent strength. a breaking 1 66 WEIGHT, STRESS, AND TENSION OF EOPES. \Veiglit of* Hemp and Wire Rope. (Molesworth.) In Lbs. per Fathom. Circum- ference. H» Common. HP. Good. Wi Iron. SE.  6 i-5 .41 •54 1.96 2 5-5 5-45 7.26 •55 •74 2.66 2-73 6 6.48 8.64 2 .72 .96 3.48 3.56 6-5 7.61 10.14 2.25 .91 1.22 4.4 4-51 7 8.82 11.76 2-5 1*13 **5 5-44 5.56 7-5 10.13 13*5 2-75 1.36 1.82 6.58 6-73 8 11.52 15-36 3 1.62 2.16 7.83 8.01 8-5 I3-05 17-34 3-25 1.9 2-54 9.19 9-4 9 14.58 19.44 3-5 2.21 2.94 10.66 10.9 10 18 24 3-75 2-53 3.38 12.23 12.52 12 26 34-56 4 2.88 3-84 13.92 14.24 15 40.52 54 To Compvite Stress upon a Rope set at an Inclination. RULE. — Multiply sine of angle of elevation by strain in Ibs., add an allow- ance for rolling friction and weight of rope, and multiply by factor of safety. Factor of safety.— For standing rope 4, for running 5, and for inclined planes from 5 to 7. ILLUSTRATION.— Inclination of rope 92.5 feet in 100, velocity 1500 feet per minute, and strain 2000 Ibs. ; what should be diam. of iron rope, 7 wires to a strand ? Angle of 92.5 feet in 100 = 43°, and sine of 43° — .682. .682 X 2000= 1364, to which is to be added rolling friction and weight of rope, assumed to be u ; hence, 1364 + 11 = 1375. Factor of safety assumed at 6, consequently 1375 X 6 = 8250 Ibs. , capacity or break- ing weight or stress of rope. By table, page 162, 8200 Ibs. is breaking weight of a wire rope of 7 strands, .625 inch in diam. To Compvite Tension of a Rope. TD — = t. v representing velocity of rope in feet per minute, EP horses1 power, and t tension in Ibs. ILLUSTRATION.— Assume wheel 7 feet in diameter, revolution 140 per minute, and IP as per preceding table, 29.6. _, 29. 6 X 33 ooo 976 800 7X3- Hi6 X 140 , 3079 To Compvite Operative Deflection of a Rope. = d. D representing distance between centres of wheels or drums in feet, w weight of rope in feet per lb., t tension, or power required to produce required power or tension of rope when at rest, and d deflection in feet. ILLUSTRATION.— Take elements of preceding case: diam. of wire rope of 7 strands = .5625 inch, and by table, page 162, w = .41 lb., and D = 300 feet. Then 10.7 X 317-2 = 10.87 feet. Capacity.— At the Falls of the river Rhine there is a wire rope in operation that transmits the power of 600 horses for a distance exceeding one mile. TRANSMISSION OF POWEK AND EQUIVALENT BELT. Endless Ropes. Wire Ropes, when practicable and proper for application, can be used for transmission of power at a less cost than belting or shafting. Transmission, of IPower. Diameter of Wheel. Jifc Is! tf^S So ll Diameter of Wheel. *N III Diamater of Rope. || 1 Diameter ( of Wheel. Revolu- tions per Minute. Diameter of Rope. II Feet. Ins. Feet. Ins. Feet. Ins. 4 80 •375 3-3 7 IOO .5625 21. 1 II I4O •6875 132.1 4 IOO •375 4.1 7 140 .5625 29.6 12 80 •75 99-3 4 1 20 •375 5 8 80 .625 22 12 IOO •75 124.1 4 140 •375 5-8 8 IOO .625 27-5 12 140 •75 173-7 5 80 •4375 6.9 8 140 .625 38.5 13 80 •75 122.6 5 IOO •4375 8.6 9 80 .625 41-5 13 IOO •75 153-2 5 120 •4375 10.3 9 IOO .625 51-9 13 120 •75 183.9 5 I4O •4375 I2.I 9 140 .625 72.6 14 80 •875 I48 6 80 •5 IO.7 10 80 •6875 58.4 14 IOO •875 I76 6 IOO •5 13-4 10 IOO .6875 73 14 120 •875 222 6 120 •5 16.1 10 140 .6875 102.2 15 80 •875 2I7 6 I40 •5 18.7 ii 80 .6875 75-5 15 IOO .875 259 7 80 •5625 16.9 ii IOO •6875 94-4 15 120 •875 300 Wire Rope and. Equivalent Belt. In substituting wire rope for an ordinary flat belt, the diameter is deter- mined by rule in practice for estimating power transmitted by a belt— viz., One horse power for every 70 square feet of running belt surface per minute. Thus, a belt 15 inches wide running at rate of 1400 feet per min- ute, its power would be equal to (1400 x 15) •— (70 x 12) = 25 horses' power. The same result is obtained by the use of a wire rope .5625 inch in diam- eter, running over a wheel 6 feet in diameter, making 130 revolutions per minute. Average life of iron wire rope with good care is from 3 to 5 yearst and that of steel rope is greater. Wear increases rapidly with velocity. GJ-eiieral Notes. — Hemp and. "Wire Ropes. White Rope, 2 inches in circumference, of different manufactures, parted at a stress of from 4413 to 6160 Ibs. Specimens of Italian, Russian, and French manufacture parted with an average stress of 5128 Ibs. = 1633 Ibs. per square inch of rope. Bearing capacity of a hemp rope is proportional to its thickness, number of its strands, slackness with which they are twisted, and quality of the hemp. Hemp and Wire Ropes. — Ultimate Strength is 2240 Ibs. per Ib. per fathom for round hemp, 3300 Ibs. for iron, 7000 Ibs. for cast-steel, and 10000 Ibs. for plough-steel. Working Load is 336 Ibs. per Ib. weight per fathom for round hemp, 660 Ibs. for iron, 1400 Ibs. for cast-steel, and 2000 Ibs. for plough-steel. Or, .83 times square of circumference in inches for round hemp, 5 times square of circumference for iron, and 9 times square of circumference for steel. (D. K. Clark.} Steel Ropes may be one half less in weight than iron or hemp for like working loads. 1 68 ROPES AND CHAINS. IRON WIRE AND UNITED STATES NAVY HEMP ROPE. Wire 6 Strands-, Hemp Core. Rope 4 Strands. Ci Actual. rcumferenc Nominal. WIRE, e. Core. Wires. Breaking Weight. Circun Actual. HEl ference. Nominal. [p. Yarns. Breaking Weight. Ins. Ins Ins. No. Lbs. Ins. Ins. No. Lbs. 7 7 2-35 108 187400 12 I3-25 1168 75966 6 6 2.25 108 104050 II 12.25 1036 77633 4-937 4-9 i-57 114 65409 10.5 11.875 928 76933 4-375 4-5 i-57 114 55316 10 n-375 876 7°533 3-5 3-36 1.27 114 34480 95 10.5 800 58766 3-187 2.98 1.17 114 28606 9 10.312 712 56466 2-75 2.68 .78 114 21846 8-5 9-437 640 42866 2-5 2-45 .78 114 15692 8 8.812 560 4OOOO 2-375 2.4 .78 42 I57I8 7-5 8-437 484 35500 2 2.06 •39 114 10925 ! 7 7.812 436 32 166 Weight and. Strength, of Stud-link Chain Cable. (English.) D Diam. of each Side. MKNSION Length of Link. 3. Width of Link. Weight Fathom. Admiralty Proof-stress (adopted by Lloyds'). D Diam. of each Side. IMKNSION Length of Link. 8. Width of Link. Weight per Fathom. Admiralty Proof-stress (adopted by Lloyds'). Ina. Ins. Ins. Lbs. Tons. Ins. Ins. Ins. Lbs. Tons. •4375 2.625 1-575 "•3 3-5 I«J 9 5-4 121 405 •5 3 1.8 134 4-5 1.625 9-75 585 I42 47-5 •5625 3-375 2.025 17.2 5-5 i-75 o-5 6-3 164.6 55-125 .625 3-75 2.25 21 7 1-875 1.25 6-75 189 6325 .6875 4.125 2.475 25.4 8-5 2 2 7-2 215 72 •75 4-5 ; 2.7 30.2 10.125 2.125 2?5 7-65 242.8 81.25 .875 5-25 3-!5 41.2 13-75 2-25 ! 35 8.1 276.2 91-125 i 6 3-6 53-8 18 2-375 425 8-55 303.2 IOI.5 1.125 6-75 4-05 69 22.75 2-5 5 336 112 5 1.25 75 4-5 84 28.125 2-75 16.5 9-9 406.6 ; 136.125 1-375 [8.25 4.95 101.6 34 i NOTE i.— Safe Working-stress is taken at half Proof-stress, 3.82 tons per sq. inch of section. •2.— Proof -stress and Safe Working - stress for close-link chains are respectively two-thirds of those of stud-link chains. 3. — Proof-stress averages 72 per cent, ultimate strength, and Ultimate Strength averages 8 tons per square inch of section of rod or one side of a link. Weight of close-link chain is about three times weight of bar from which it is made, for equal lengths. Karl von Ott, comparing weight, cost, and strength of the three materials, hemp, iron wire, and chain iron, concludes that the proportion between cost of hemp rope, wire rope, and chain is as 2 : i : 3 , and that, therefore, for equal resistances, wire rope is only half the cost of hemp rope, and a third of cost of chains. Safe "Working Load of Chains. (Molesworth). Diameter of Iron. Load. Diameter of Iron. Load. Diameter of Iron. Load. Diameter Load. Ins. •375 •5625 .625 Lbs. 2240 3800 4900 6270 Ins. .6875 •75 .8125 •875 Lbs. 7390 8960 10280 12320 Ins. •9375 I 1.0625 1.125 Lbs. 13700 15680 17920 20 160 Ins. 1.1875 1.25 I-3I25 1-375 Lbs. 22 4OO 24640 26680 30240 ROPES AND CHAINS. 169 Breaking Strain and IProof of Chain Cables. Diam. of Chain. Breaking Strain. Diam. .of Chain. Breakinf Strain. Diam. of Chain. Breaking Strain. Diam. of Chain. Breaking Strain. Ins. I 1.0625 I.I25 Lbs. 67700 75640 84 100 I.l875 1.25 1-375 Lbs. 92940 102 160 121 840 Ins. 1-5 1.625 i-75 Lbs. I43IOO 165 920 2l6 120 Ins. 2 2.125 2.25 Lbs. 243 1 80 272580 303280 Proof-stress is 50 per cent, of estimated strength of weakest link and 46 per cent, of strongest. Comparison, of" "Wire Ropes and Tarred. Hemp Rope, Hawsers, and Cables. COARSE LAID. FINE LAID. Ropes. Haws'rs. Cables. Ropes. Haws'rs. Cables. Diam- | Safe 11 4 §a Ii if Diam- Safe rt H II eter. g Load. £g tajl £g £ « eter. Load. (2S ££ •F £ 5 H35 02  — •5 1875 3-12 2.87 — •3125 i 690 2-43 2.25 3-32 — •5625 2420 3-56 3-25 4.87 •375 1.25 825 2.68 2-375 3-5 — 625 2900 3-93 3-62 5-25 •5 1600 2.87 2.62 3-87 — •75 4320 4.81 4-37 6-37 -5625 !-75 2800 3-8i 3-5 — •875 5700 5-5 5 7-25 .6875 2.125 3800 4-75 4-25 6^2 — i 8200 7-25 6.25 8-75 •75 2-375 4400 5-25 4.87 7 — 1.125 IO IOO 8.18 7 9-5 •875 2.625 6 150 6.12 5-75 8 8 1.25 13600 8.81 8.06 ii 3 8400 6.62 6.12 8.62 8.62 «•! 17500 10 9-75 12.5 •25 3-75 13400 8.81 8-5 10.93 10.93 1.625 21800 n.x8 10.93 •375 4-25 16800 9.87 9-56 12.25 12.12 i-75 27000 12.5 12.12 — .5 4.625 20 160 10.75 10.5 13 13.12 1875 32500 — .625 5 24600 - 11.87 ii 56 "•75 2 37000 — — — In above table, determination of circumference of rope, etc., is based upon Breaking Weight or Tensile resistance of wire being reduced by one fourth, and ultimate resistances of rope, etc., are reduced one third. Result of Experiments upon "Wire Rope at TJ. S. Navy- Yard, Washington. -(J A Roebling's Sons.) Circumfe Actual. rence. Nom- inal. ill 1§ Weight Foot. Breaking Weight. Circumft Actual. rence. Nom- inal. tii rf * *~Z jj!^ No. 13 14 14 17 20 18 19 III Breaking Weight. Ins. 4-9375 4-375 3-9375 3-5 3-1875 2-75 2.6875 2-5 Ins.  18 Lbs. 3-14 2.15 2.0875 I-I525 1.09 1.0275 1.0225 .14 Lbs. 65409 55 3l6 44420 34840 28606 21846 18810 15692 Ins. 2-375 2.1875 2 1-9375 1-4375 1-3125 1.125  •05 -035 Lbs. I57I8 14478 10925 10 118 7880 5687 4428 3729 To Compute Circumference of Wire Rope with Hemp Core, of Corresponding Strength to Hemp Rope, and of Hemp Rope to Circumference of "Wire Rope. RULE i. — Multiply square of circumference of hemp rope by .223 for iron wire and .12 for steel, and extract square root of product. 2.— Multiply square of circumference of hemp-core wire rope by 4.5 for iron wire and 8.4 for steel wire. EXAMPLE.— What are the circumferences of an iron and steel wire rope corre- sponding to one of hemp-core, having a circumference of 8 ins. ? /82X .223 = 3. 78 in*, trow, and i '82x.i2 = 2. 77 ins. steel. ROPES, HAWSEKS, AND CABLES. ROPES, HAWSERS, AND CABLES. Ropes of hemp fibres are laid with three or four strands of twisted fibres, and are made up to a circumference of 12 ins., and those of four strands up to 8 ins. are fully i6per cent, stronger than those of three strands. Hawsers are laid with three or four strands of rope. Cables are laid with but three strands of rope. Hawsers and Cables, from having a less propor- tionate number of fibres, and from the irregularity of the resistance of their fibres in consequence of the twisting of them, have less strength than ropes, difference varying from 35 to 45 per cent., being greatest with least circum- ference, and those of three strands up to 12 ins. are fully loper cent, strong- er than those having four strands. Tarred ropes, hawsers, etc., have 25 per cent, less strength than white ropes ; this is in consequence of the injury fibres receive from the high tem- perature of the tar, viz. 290°. Tarred hemp and Manila ropes are of about equal strength, and have from 25 to 30 per cent, less strength than white ropes. White ropes are more durable than tarred. The greater degree of twisting given to fibres of a rope, etc., less its strength, as exterior, alone resists greater portion of strain. Ultimate strength of ropes varies from 7000 to 12000 Ibs. per square inch of section, according as they are wetted, tarred, or dry. One sixth of ulti- mate strength is a safe working load= 1166 to 2000 Ibs. per square inch. Units for computing Safe Strain th.at may "be "borne "by N~e\v Ropes, Hawsers, and. Catoles. (t^. S. Navy.) DESCRIP- TION. Circumference. Wl 3 strands. Ron ite. 4 strands. ts. Tar 3 str'ds. red. 4 str'ds. HAW White. 3 str'ds. SEES. Tarred. 3 str'ds. CAI  600 u 6 " 8 1090 I20O — — 570 — 510 — u 8 " 12 1045 880 — —  " 8 — — 825 940 — 480 — — u 8 " 12 — — 780 820  2.5 " 6 810 950 — — 440 — — tt 6 " 12 760 835 — — 465  by a Manila rope of 3 strands, having a circumference of 6 inches ? (See Rule, page 167. ) 62 = 27360^5. When it is required to ascertain weight or strain that can be borne by ropes, etc., in general use, preceding Units should be reduced from one third to two thirds, in order to meet their condition or reduction of their strength by chafing and exposure to weather. Molesworth's table is based upon a reduction of three fourths. ILLUSTRATION. — What weight can be borne by a tarred hawser of 3 strands. 10 inches in circumference, in general use? io2 X (505 — 505 -r- 3) = zoo X 336.67 = 33 667 #*• HOPES, HAWSERS, AND CABLES. Destructive Strength, of* Tarred. Hemp Ropes. (D. K. Clark.) Circum. Diam. Res Common Cold. ister. Russian Warm. Circum. Diam. Reg Common Cold. wter. Russian Warm. Ins. 3 3-5 4 4-5 5 Ins. •95 i. ii 1.27 1-43 i-59 Lbs. 7390 II 200 I3IOO 16330 19580 Lbs. 8620 II 760 15340 19440 23990 Ins. 5-5 6 6-5 7 8 1-75 1.91 2.07 2.24 2-54 Lbs. 24800 28985 34030 40320 52480 Lbs. 29120 33150 40550 47041 61420 Specimens furnished by National Association of Rope and Twine, Spinner*, As tested by Mr. Kirkaldy. Ron. Circum- ference. Weight perLb. Extreme Strength. Breaking Weight per Ib.per Fathom. Extend atStre 1000 Ibs. >n In 50 in ss per Ib. r Fathom 2000 IDS. s. Length W*h. 3000 Ibs. Rus Ma< Hai Br a 9 £ 5 sian 3hine id-sp eaki 5 rope ... 48 thr yarn. . . 50 ' an yarn, 51 * ing Streng Old Method. Common Best Hemp. Russian. ds. tn I Cc Ins. 5-26 5-37 5-39 of a y Regist Id. W Lbs .92 .85 1. 00 ^arr sr. arm. 6 i 6 ec i ! I I I 1 > Lbs. 1088 1514 8278 Hei § 5 Lbs. 1933 2152 3024 np R OldM Common Hemp. Ins. 5-29 4-53 4.46 opes. ethod. Best Russian. Ins. 6.56 5-91 (Mr. By Re Cold. Ins. 6.63 Plynn.) gister. Warm. Ins. 3 3-5 4 4-5 5 Ins. •95 i. ii 1.27 J-43 i-59 Lbs. 5056 7466 8780 10300 13328 Lbs. 6248 8668 10460 12432 15859 Lbs. 7392 II 2OO I3I04 16330 20496 Lbs. 8624 II 760 17810 19443 23990 Ins. 565 6.5 8 Ins. 1-75 I.9I 2.O7 2.24 2-54 Lbs. 15456 18144 20518 22938 26680 Lbs. 18414 2l6lO 23 610 27462 32032 Lbs. 24797 28986 34630 40320 52483 Lbs. 29120 33150 40544 47040 61420 To Compute Strain that may "be borne witn safety t>y new Ropes, Hawsers, and. Cables. Deduced from experiments of Russian Government upon relative strength of different Circumferences of Ropes, Hawsers, etc. U. 8. Navy test is 4200 Ibs. for a White rope of three strands of best Riga hemp, of 1.75 inches in circumference (= 17000 Ibs. per square inch ofjibre), but in preceding table (page 166) 14000 Ibs. is taken as unit of strain that may be borne with safety. RULE.— Square circumference of rope, hawser, etc., and multiply it by Units in table. To Compute Circumference of a Rope, Hawser, or Cat>le for a GKven Strain. RULE. — Divide strain in pounds by appropriate units in preceding table, and square root of product will give circumference of rope, etc., in ins. EXAMPLE i.— Stress to be borne in safety is 165 550 Ibs. ; what should be circum- ference of a tarred cable to withstand it? 165 552 -r- 550 = 301, and -v/301 = J7- 35 ins- 2.— What should be circumference of a Manila cable to withstand a strain, in general ttse, of 149 336 Ibs. ? Assuming circumference to exceed 18 ins., unit = 560. 149 336 -r- (560 — 560-7-3) = 400, and V400 = 20 *'«*• 172 KOPES, HAWSERS, AND CABLES. To Compute "Weignt of Ropes, Hawsers, and Catoles. RULE. — Square circumference, and multiply it by appropriate unit in following table, and product will give weight per foot in Ibs. : HAWSERS. HOPES. CABLES. 3 strand Hemp 032 .031 .031 3-strand tarred Hemp, .042 .041 .041 3-strand Manila 032 .031 .031 4-strand Hemp 033 — — 4-strand tarred Hemp, .048 — — 4-strand Manila 035 .034 .034 Units for Thread Ropes is same as that for Ropes of like material. EXAMPLE.— What is weight of a coil of lo-inch Manila hawser of 4 strands of 120 fathoms? io2 X .034 = 3. 4, and 120 X 6 X 3- 4 = 2448 Ibs. Weignt and. Strength, of Hemp and Wire Ropes. (Molesworth.) C representing circumference in ins., W weight of rope in Ibs. per fathom, L working load in tons, and S destructive stress in tons. VALUES OF y, X, AND k. ROPES. y X k ROPES. y X k Hawser, hemp ' '31 Warm register, hemp .7 .116 Cable " Manila hawser • *77 .27 •045 Tarred hawser hemp ' ' cable IQ 03 3 ' ' cable ' ' Iron rope .87 1.8 ,2Q Cold register. ". .6 .1 Steel ". .80 2.8 .4^ To Compute Circumference of Hemp or "Wire Rope for Fore or ]Vtaiii Standing Rigging. (V. S. Navy.) RULE. — To length of mast between partners and deck, add half extreme breadth of beam of vessel and divide sum by half extreme breadth. Mul- tiply quotient by half square root of tonnage (OM) and extract square root of product. For Mizzen, take .74 of Fore and Main. EXAMPLE. — Required circumference of hemp rope, for main - mast of a vessel having a breadth of beam of 45 feet and a burden of 3213 tons? Extreme length of mast ____ .................. 94.4 feet. Depth of hold, or total bury of mast, 21.4 feet. Head .............................. 15 " 36.4 " Breadth of beam, 45 feet. 58 + 15--:- 1s- = 3. 58, and 58 " 6 = io.n ins. Then if circumference for a wire rope is required, see table, page 164. 