The Railway Library, 1909. Various
Читать онлайн книгу.
locomotive on each gradient,
level being unit.
Col G: Number of locomotives of equal power necessary to carry
the same load up each gradient.
| A | B | C | D | E | F | G | |
| From Harrisburg to Lewistown, 60–7/10 miles | { | 16 | 346.6 | 207.9 | 0.534 | 1.87 | |
| 8 | 454.3 | 272.6 | 0.697 | 1.42 | |||
| From Lewistown to foot of Allegheny Mts., 72 miles | { | 21 | 300.7 | 180.4 | 0.464 | 2.15 | |
| 10½ | 414.6 | 248.8 | 0.640 | 1.56 | |||
| From foot to summit of Allegheny Mountains, 12–3/10 miles | { | 80 | 105.6 | 63.4 | 0.163 | 6.13 | |
| Level | 648.0 | 388.8 | 1.000 | 1.00 | |||
| From summit to Pittsburg, 106 miles | { | 47 | 172.4 | 103.4 | 0.266 | 3.76 | |
| 50 | 50 | 163.7 | 98.2 | 0.252 | 3.95 | ||
| 52.8 | 52.8 | 156.2 | 93.7 | 0.241 | 4.14 | ||
It will be perceived from the foregoing table that three locomotives are fully sufficient to transport the same load up the 80 feet gradient that two will carry on the gradient of the western division, and one on the eastern; hence the practical working of the road on the two methods of ascent would be to run two locomotives with the load brought from below from Logan's Narrows to the summit, say 31¾ miles, up the 50 feet gradient; while, on the other, the same engine that brought the load from Harrisburg would continue with it to Robinson's (15 miles), where it would accompany the two destined for Pittsburg to the summit of the mountain and return.
In the first case the engines together will have traveled 63½ miles, and, in the other, the three 51¾, leaving a difference in distance to be traveled by the moving power due to each full train, from the east, 11¾ miles in favor of the 80 feet gradient.
In practice it will therefore be seen—chiefly on account of the actual distance saved—that transportation can be afforded cheaper, in this case, on the 80 feet gradient than on the 50, without bringing into the estimate the interest on $841,000 that the latter would cost to obtain it more than the former. Under these circumstances we did not hesitate when the choice of routes was reduced to a selection between these two methods of overcoming the mountain, to decide in favor of the line by Robinson's, which has the additional advantage of bringing us within 6–⅓ miles of Hollidaysburg, where a connection may be made with