Fig. 13.
The chains have links of three-quarters-inch to one-inch diameter, and are made of iron, sometimes of steel. Their constant use necessarily subjects them to great wear, and as they are also often exposed to severe shocks (especially the hoisting chain) they must be made of the very best material and in the most careful manner. At present iron chains are preferred to those made of steel: they are more durable, and less likely to break under severe shocks. Steel chains have suffered in reputation through rapid wear and frequent breakages occurring within the last few years, but with increased experience in their manufacture and use they will undoubtedly be improved, and eventually take the lead over iron chains.
The propelling mechanism consists of an endless chain connecting one or more axles of the truck or supporting wheels with the shaft of the hoisting drum by means of friction clutches or positive gearing. The usual speed is five to six miles per hour.
FIG. 9.—OTIS-CHAPMAN STEAM SHOVEL; John Souther & Co., Boston, Mass.
Steam shovels of seven of the most prominent manufacturers are shown in Figs. [1] to [9], and the general particulars of each are given in condensed form in Table I. In each case the boiler is upright.
TABLE I.—General Description of the Important Parts of the Most Prominent Makes of Steam Shovels.
| <—Frame—> | ||||||||||
| Fig. | Shovel. | Material. | Size, ft. | Running gear. | Gage, ft. ins. | B'l'r | Eng- ine | Cylinder, ins. | H'st'g gear. | |
| [1]. | Osgood | Wood | 10 × 34 | 2 trucks | 4 8½ | V | H | 2 | 10 × 12 | F |
| " | " | 10 × 30 | " | " | " | " | " | 8¼ × 10 | F | |
| " | " | 10 × 25 | " | " | " | " | " | 7 × 10 | F | |
| [2]. | Thompson | {I-be'm} | 10 × 32 | " | " | " | " | " | 10 × 14 | F |
| " | {and} | 10 × 30 | " | " | " | " | " | 8 × 12 | F | |
| " | {chan- } | 10 × 28 | " | " | " | " | " | 8 × 10 | F | |
| " | {nels} | 10 × 24 | " | " | " | " | " | 6 × 8 | F | |
| [3]. | Barnhart | " | 10 × 28 | " | " | " | V | " | 8 × 10 | F |
| " | " | 10 × 26 | " | " | " | H | 1 | 8 × 10 | F | |
| " | " | 10 × 24 | " | " | " | V | " | 8 × 10 | F | |
| " | " | 10 × 22 | " | " | " | " | " | 6 × 8 | F | |
| [5]. | Victor | " | 10 × 30 | " | " | " | H | 2 | 8 × 10 | F |
| [6]. | Clement | " | 10 × 30 | " | " | " | " | " | 8 × 10 | P |
| [7]. | Giant | " | 10 × 35A | " | " | " | " | " | 13 × 16 | F |
| " | " | 10 × 35 | " | " | " | " | " | 8 × 12 | F | |
| " | " | 10 × 30 | " | " | " | " | " | 7 × 11 | F | |
| [8]. | Little Giant | " | 7 × 23 | {4 r'd wh | 8 0 | " | " | " | 7 × 11 | F |
| " " | " | 6 × 23 | {4 r'd wh | 8 0 | " | " | " | 6 × 8 | F | |
| [9]. | Otis-Ch'pm'n | Wood | 10 × 22 | {4 fl'ge wh | 7 10 | " | V | 1 | 10 × 12 | P |
| " | " | 10 × 18 | {4 fl'ge wh | 7 10 | " | " | " | 8 × 10 | P | |
Transcriber's Note:
Boiler and Engine—V=Vert., H=Hor.
Hoisting Gear—F=Friction Clutch, P=Positive