PERFORMANCE AND COST OF OPERATING LOCOMOTIVES.
QUESTION 445. _What is the cost of operating ordinary locomotives per
mile run?_
_Answer._ The average cost at the present time (1874) is from 20 to 25
cents per mile.[103]
[103] Deducting 10 per cent. from this amount will give very nearly
the gold value of the cost. The figures given above represent
the cost in the depreciated promises to pay of the United States
Government.
QUESTION 446. _What items of cost are included in this, and what
proportion do they each bear to the total cost?_
_Answer._ The items of cost and the percentage of each to the whole
expense of operating locomotives, and also to the total of all the
expenses of operating locomotives are given in the following table:
======================+===========+============+=============
| | | Percentage
| | Percentage | of total
|Approximate| of total | cost of all
| average | cost of |the operating
| cost per | operating |expenses of
| mile run. |locomotives.| railroads.
----------------------+-----------+------------+-------------
Fuel | 6.0 cts. | 0.30 | .03
----------------------+-----------+------------+-------------
Oil and waste | 0.4 cts. | 0.02 | .004
----------------------+-----------+------------+-------------
Wages of locomotive | | |
runners and firemen | 6.0 cts. | 0.30 | .06
----------------------+-----------+------------+-------------
Repairs of locomotives| 7.0 cts. | 0.35 | .07
----------------------+-----------+------------+-------------
Cleaning locomotives | 0.6 cts. | 0.03 | .006
----------------------+-----------+------------+-------------
Total | 20.0 cts. | 1.00 | .20
======================+===========+============+=============
From this table it will be seen that the locomotive expenses are 20
per cent. of the whole cost of operating railroads. This cost of course
varies under different circumstances. The above is probably somewhat
lower than the average cost in this country.
QUESTION 447. _How many miles do locomotives ordinarily run per ton of
coal and per cord of wood?_
_Answer._ This also varies greatly under different circumstances. An
average taken from the monthly reports of 52 different roads gives 38
miles run per ton of coal, and an average from the reports of 16 roads
gives 47¹⁄₂ miles run per cord of wood. No deductions should, however,
be made from this of the relative value of wood and coal for fuel,
because the trains which are run with wood for fuel are usually lighter
than those hauled with coal-burning engines. The above figures are the
average results during the month of May, 1871, of all the trains on the
roads from whose locomotive reports it has been compiled. The following
report of experiments, which were carefully made by the writer, will
give the performance of a locomotive when great care is taken to
produce good results. It should be stated, however, that the engine
with which these experiments were made had been in service eighteen
months, without receiving thorough repairs, and that the boiler at
times primed badly, so that the rate of evaporation of water per pound
of coal is not a fair indication of the performance of the engine in
that respect. The coal used was known as Brazil coal, from Indiana, and
in order to compare the performance of two engines only lumps of coal
were used, so as to leave no room for question regarding the relative
amount of fine coal used by each engine. The maximum grades on the road
on which the experiments were made were 30 feet per mile, and the
total ascent from the lowest to the highest point on the road was 374
feet.
LOCOMOTIVE EXPERIMENTS.
1873. 1873. 1873.
Date of experiment July 21. July 28. August 2.
Number of miles run 145 145 145
Number of cars hauled 41 31 41
Total weight of cars, lbs. 1,497,240 1,119,650 1,508,860
Total amount of coal burned, lbs. 8,676 5,102 7,221
Total am’nt of water consumed, lbs. 63,531 45,719 52,609
Water evaporated per lb. of coal, lbs. 7.32 8.02 7.04
Miles run per ton (of 2,000 lbs.) of
coal 33.4 50.8 38.8
Coal consumed per car per mile, lbs. 1.45 1.13 1.21
Average speed, including stops, miles 11.1 13 13.8
QUESTION 448. _How can we determine the speed at which an engine is
running?_
_Answer._ In the absence of any special instruments for the purpose, BY
COUNTING THE NUMBER OF REVOLUTIONS OF THE DRIVING-WHEELS PER MINUTE,
THEN MULTIPLYING THE LENGTH OF THEIR CIRCUMFERENCE IN INCHES BY THE
NUMBER OF THEIR REVOLUTIONS PER MINUTE AND THE PRODUCT BY 60, AND
DIVIDING THE LAST PRODUCT BY 63,360. THE QUOTIENT WILL BE THE SPEED
IN MILES PER HOUR. Thus, supposing driving-wheels which are 61¹⁄₂ in.
in diameter, and whose circumference is therefore 193.2 in., should
make 164 revolutions per minute, then 193.2 × 164 × 60 ÷ 63,360 = 30,
(nearly) miles per hour.