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way to engage the strap of block, therefore when the word “shackle,” without further description, is used, it is always fitted in this manner. Where, however, it is essential to have it with the shackle pin running parallel with sheave pin (as is often necessary to get the falls of a tackle to lead in line with hauling part) the words " reverse shackle” must be used. If the shackle be required with its jaw uppermost, “reverse upset shackle” should be specified.

It often happens that a block is required with an eye to engage a shackle, which the blockmaker is not required to furnish. In such cases it is well to state whether the eye should be " worked " or a “shackle-eye” wanted. A “worked eye,” of course, is one having its edge worked round like a ring, the "shackle-eye'' being drilled straight through, so that the inserted pin bears along its entire length. For a given diameter of pin, that in a shackle-eye would be twice as strong as the one bearing on a worked eye, so that where other considerations do not count, it is economy to fit a shackle eye.

Beckets are small eyes fastened at the breech end of blocks to take the thimble on the standing part of a tackle. They are useful to have on all spare tackle blocks.

Strops. When blocks are intended for brace or guy pendants, they should be specified as having a score cut to receive the rope strop.

Hooks should not be used on blocks where heavy loads are dealt with. For loads under. ten tons they are equally reliable with shackles, besides being handier. They should be specified as “ loose, 66 stiff front,

"swivel ” hook, as required, and the working load given in all cases, as many of the hooks on low grade blocks are considerably inferior in strength to the other parts of the fitting.

Sister, or Match Hooks are used for a variety of purposes, and consist of two hooks on a common eye, arranged to open, and when closed, to form a seemingly solid eye.

Lashing Shackles are especially iarge in the bow, and wider at the jaws, than ordinary shackles, being fitted to the heavier classes of double and treble blocks, to permit of their taking a Manila or wire

rope lashing Swivel Jaws are sometimes fitted to the upper block in davit tackles.

Appended is a table giving actual weights of blocks, fitted with shackles and beckets complete, which will be of use in estimating rigging and outfit weights.

side,"

or

GUNS.

210

200

175

150

8.3 50 18.6 275

7.9 50 16.2

231

6.9 45 10.0

165

6.9 50 10.8

165

5.9 45 6.3

99

5.9 50 6.8

99

3,116 18,572

28.3

3,116 15,601

2,952 10,000 22.1

3,116 11,143 23.9

2952 6001 18.2

3116 6886 20.1

19.2

13.8

15.2

[blocks in formation]
[blocks in formation]

8.3 45 17.3 275

7.9 45 14.9 231

2,952 16,667

26.2

2,952 14,002

24.3

26.3

17.5

16.1

17.3

2.5 50 0.55 8.8

2.5 60 0.76 8.8

2.21 50 0.45 6

2.21 60 0.55 6

1.8
60
0.30
3.3

2952
533
7.9

3116
594
9.1

2952
362
7.1

400
7.5

3116

223 5.9

119 5.0

stated.

[blocks in formation]

Tot. len. of gun in ft.
Len. of bore, ins..
Wt. of gun, lbs.
Wt. of gun, tons.

9.84 11.07 12.30 13.78 15.5 17.22 15.75 17.7 19.69 19.55 22.00 24.14 108.66 123.43 138.19 153.55 174.21 194.89 175.20 199.25 222.45 218.12 247.49 276.78

1488 1711 1936 3748 4189 4740 5512 6283 7055 10,582 12,015 13,558
0.66 0.76

0.86 1.67 1.86 2.11 2.45 2.79 3.14 4.70 5.34 6.03
11.5 11.5 11.5 30.86 30.86 30.86 46.30 46.30 46.30 90.39 90.39 90.39
14.6 14.6 14.6 39.68 39.68 39.68 59.52 59.52 59.52 112.4 112.4 112.4
2.77 3.12 3.54 10.47 12.57 14.33 15.66 17.97 20.62 29.99 34.40 39.47
2690 2890 3068 2835 3022 3199

2877 3038 3225 2854 3008

3196
2388 2566 2723 2500 2661 2822 2539 2677 2841 2556 2697 2858
665 749 1720
1952 2191 2659 2969 3340

5099 5680 6389
7.13 7.91 8.53 10.87 11.92 12.93 12.87 13.90 15.15 16.15 17.41 18.98

[blocks in formation]

576

Muz. energy tot. ft.-tons.
Per. thro. steel in ins.
Per. thro. iron, Tresidder's

formula... Per. Krupp st., 3000 yds...

9.9

11.0

11.7

14.7

17.24

18.77

18.35 3.52

19.91 3.74

21.77 4.02

26.66 4.98

24.52 5.29

26.84 5.66

[blocks in formation]

Tot. len. of gun in ft..

27.56 30.5 34.45 31.50 35.4 39.37 36.75 41.3 45.93 40.3 45.0 50.03
Len. of bore, ins..

305.91 347.29 388.59 350.80 398.28 445.28 409.46 464.62 519.70 445.67 505.95 565.76
Wt. of gun, Ibs.

29,321 33,279 37,258 44,092 50,265 56,438 70,105 79,907 89,507 90,609 103,174 120,141 Wt. of gun, tons.

13.03 14.80 16.56 19.60 22.34 25.09 31.16 35.48 39.79 40.28 44.86 51.45

S 249.1 249.1 249.1 374.48 374.48 374.48 595.2 595.2 595.2 771.6 771.6 771.6
Wt. of st. proj, in lbs.

308.6 308.6 308.6 474.0 474.0 474.0 460.6 460.6 460.6 981.0 981.0 981.0
Wt. of ch, in lbs.

82.47 94.59 108.71 124.58 143.10 164.27 198.41 227.07 262.35 255.73 293.21 337.30 2,851 3,015 3,196 2,854 3,018 3,199 2,854

3,018 3,202 2,854

3,018 3,199
Muz. vel. in ft.-secs..
2,559 2,707 2,868 2,533 2,687 2,845 2,523 2,664 2,835

2,526 2,674

2,838
Muz. energy tot. ft.-tons. 14,037 15,684 17,620 21,169 23,718 26,655 33,561 37,595 42,435 42,564 48,728 54,859
Per. thro. steel in ins.

23.20 25.13 27.30 26.96 29. 20 31.73 31.80 34.45 37.48 34.94 37.84 41.10
Per, thro. iron, Tresidder's
formula.

31.73 34.51 37.65 36.47 39.66 43.27 42.52 46.28 50.57 46.42 50.47 55.08 Per. Krupp st., 3000 yds... 8.14 8.65 9.22 9.84 10.45 11.13 12.11 12.86 13.70 13.58 14.41

15.39

BETHLEHEM

ORDNANCE.

[graphic]

LEN.

PER.

Dan-
OF

WT.
Wr.

Per. of B. CAL. BORE CAL.

Hard-faced

gerous
OF

GAVRE
OF

GUN. PROJ. Veloc-
IN

En- FORM-
Space

Arm.

En-
CAL.

for
ity.

Pierc. ergy. ULA. Tar- ergy. Proj. with

Normal

High. Impact. Ins. Cals. Cms. Lbs. Lbs. Ft.-lb. Ft.- Ins. Yds. Ft.- Ins.

sec.
tons.

tons.
1.457 50 3.7 120 1 2150 37
1.831 50 4.7 550 3 2400 119
2.244 50 5.7 960 6 2400 240
3 50 7.62 1900 13

2800

707 Tons. 4

45 10.16 2.3 33 2600 1545 9.8 240 755 4 50 10.16 2.6 33 3000 2060 12.1 315

1,000 5

45 12.7 3.4 60 2600 2810 12.8 255 1,575 5 50 12.7 4.75 60 3000 3745 15.8 340 2,035 6

45 15.24 7.2 105 2600 4965 16.9 275 2,970 6.9 6

50 15.24 8.4 105 3000 6550 20.0 365 3,950 8.3 7 45 17.78) 12.7 165 2800 8965 23.2 330

9.5 7 50 17.78 14.5 165 3000 10,300 25.5

385 6,640 10.4 8 35

20.32 15.2 316 2250 10,500 28.3 235 8,240 11.0 8 45 20.32 18.6 260 2800 14,230 29.1 350 9,860

12.3 8

50 20.32 22.3 260 3000 16,220 32.2 405 11,350 13.4 10 35 25.4 30.0 604 2250 21,200 38.6

245 16,580 14.8 10 45 25.4 35.4 515 2800 27,990 40.8 370 21,080

17.2 10 50 25.4 43.9 515 3000 32,110 44.7 430 24,070 18.7 12 35 30.48 52.0 1046 2250 36,700 50.1 250 29,880 19.1 2 45 30.48 53.8 870 2800 47,290 51.7 380 36,790

21.7
2
50 30.48 66

870
3000 54,280 57.1 435 42,350

23.7 4

35 35.56 57.4 1660 2150 53,190 50.4 230 44,660 22.3
4
45 35.56 70.3 1350

2450
56,170 52.4 295 45,090

22.4
8
30 45.72 60.0 2075 2150

66,490 49.2

225 52,750 21.1

Guns less than 3" cals. are chambered for fixed ammunition with the powder nd projectiles in brass cartridge cases. Guns from 3'' cals. upwards, and includig the 6" L 45 gun, can be chambered to use either fixed ammunition, or loose mmunition with the powder in cartridge bags and the projectile separate from the owder. Guns above 6' cal. and including the 6" L 45 gun are chambered for ose ammunition. The breech mechanisms of all guns up to 10' are operated by

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