following discussion may prove suggestive:

A train moving at a rate of 60 ft. per sec., and reaching the foot of a
grade, will have acquired a "velocity head" of 56.7 ft., equivalent to
stored energy of 56.7 × 2,000 = 113,400 ft-lb. per ton. On a 0.002
grade (as in Item 15 of Table 1) the resistance would be, gravity
4 lb. + train 4.7 lb. = 8.7 lb., against which the energy above given
would carry the train through 113,400 ÷ 8.7 = 13,034 ft., say, 2.5
miles, leaving 5 miles to be provided for by the steam production.
Examining the items in the table having grades in excess of 10 miles, it
will be noted that 16% is about all the weight on drivers which can be
utilized by the current supply of steam. In Item 15 the energy derived
from all sources is equivalent to 24.3%; hence the stored heat may be
considered as responsible for an equivalent of 24.3% - 16% = 8.3% for a
distance of 5 miles.


TABLE 1.

===========================================================================
Item No.
|Length of grade, in miles.
| |Rate of grade.
| | |Maximum curvature.
| | | |Compensation.
| | | | |Gross weight of load, in tons.
| | | | | |Weight of tender, in tons.
| | | | | | |Weight of locomotive, in tons.
| | | | | | | |Weight on drivers, in tons.
| | | | | | | | |Percentage of weight on