THE STEAM LOCOMOTIVE

complicated monsters that they eventually became by the time of the
termination of their economic usefulness. Up to comparatively near
the last days of its economic utility, the steam locomotive was the
most rapid specimen of land space-covering capacity mechanism in
existence, although at the time of its early invention, on one
occasion, it lost out in a race with a horse! It must be noted that
the earliest railway cars were first moved by horses. Also the
early canal boats were powered by horses. As steam locomotive
power, for early railroad transportation, eventually became
substituted for horse power, the steam locomotive naturally earned
a permanent sobriquet, ‘The Iron Horse’ a sobriquet
manifesting a superior potential power capacity and speed
achievement rather than any pictorial or organic resemblance.

The early locomotives were fired with wood, and wood continued
to be the universal fuel, due, at the time, to quantity and
availability, for quite a number of years after the Civil War.
However, as power demands became greater, locomotives converted to
coal-burners while some of the very last locomotives were fired
with oil. With the latest very large locomotives, the greater grate
and heating surface required an hourly coal consumption of 65,000
pounds, or 75,000 pounds under extreme conditions. Consequently, in
the largest locomotives mechanical stokers were a positive
necessity to replace the hand-firing method.

While there was a constant and progressive mechanical
improvement in locomotive design and construction, yet there was
one model that served quite consistently throughout a number of
years years prior to the Civil War and well past the ‘Gay
Nineties’ and into quite a bit of the 20th century. It served
throughout the wood-burning era and deep into the coal-firing
stage. This model with a wheel-arrangement of 4-4-0 and a Stephen
link-motion valve gear, was universally known as ‘The American
Standard’ type of locomotive. In its time, it served most
efficiently as a general ‘all-around work-horse’ for every
variety of railroad service. It served equally efficient as a
switch engine, a light freight engine and a fast passenger engine.
It was especially adapted for fast passenger serve as its design
permitted great speed rather than attractive and pulling capacity.
It broke all records in the matter of speed.

Due to the later development and competition of the
passenger-carrying airplanes, the interstate bus-passenger service
and the great number of privately owned automobiles,
railroad-passenger service patronage diminished to such a low ebb
as to cause the passenger-service division to operate financially
‘in the red.’ To recoup for this financial loss of
passenger revenue and to remain financially solvent, it was
necessary, as a pure economic justification, to cut passenger
service to its absolute minimum, and increase the profit-producing
freight service to its absolute limits, which, in materialistic
economics, meant bigger and longer freight trains, and which
required bigger and more powerful locomotives to haul the longer
trains.

It is patiently evident, due to structural limitations that
‘The American Standard’ type of locomotive would seriously
lack sufficient attractive power to pull the excessively longer
freight trains. To accomplish this objective it was necessary to
get a greater number of drive wheels in contact with the rails and
with power sufficient to turn them to the capacity of their
tractive potential. This meant locomotives with larger grate and
heating surfaces. Due to structural limiting factors, this
additional demand could be met only by lengthening the locomotive
boiler to a considerable extent. To expedite this requirement, it
was evident that the typical motive-power equipment – two steam
cylinders and other necessary driving equipment – was not feasible
structurally and mechanically power-producing to utilize fully the
extra power-producing capacity of the elongated boiler. To meet the
contingencies of extra capacity, a new design of the mechanical
power equipment was effected by installing a second power unit an
exact duplication of the power unit that is customarily under the
boiler – thus, making a power-combination of four steam cylinders;
and therefore, making it possible for a locomotive to have a
maximum of twenty drive wheels. This new type of locomotive was
classified as an ‘Articulated Mallet Locomotive.’ A
locomotive of this monstrous size, with two lead wheels and two
trailer wheels, would have a wheel arrangement listed as 2-10-10-2,
with each drive-wheel load being between 25,000 lbs. and 33,000
lbs., and having a gross power rating of 6,000 horsepower.

The greatest difficulty encountered in the manufacturing of
excessively large locomotives is due to the limiting manufacturing
‘space factors.’ The ‘width factor’ is practically
fixed and unchangeable (maximum width 11 ft. and 6 in.); the
‘height and depth factor’ (maximum height 16 ft.). The only
‘space factor’ without limitations (other than structural
limitations) is the ‘length factor.’ In the larger
locomotives, the increased diameter of the boiler-barrel caused
insufficient space for under-the-boiler installations and
consequently drove the Stephenson link-motion valve gear out from
under the locomotive. There was no room under the boiler for the
four enlarged eccentrics and related valve gear that would be
required by the larger locomotives. With the Stephen link-motion
becoming obsolete, necessity and convenience of location the
Walschaert valve gear the ideal valve gear for the larger
locomotives. It is noteworthy that the Walschaert valve gear was on
European locomotives some forty years, in spite that its outside
location afforded greater accessibility for inspection and repair,
before its final adoption by American locomotive builders. It was
through sheer conservatism (stupid bullhead ness), even though the
Walschaert valve gear was the most efficient in regard to perfect
steam distribution, that deterred the adoption of this efficient
valve gear until the combined forces of circumstances actually
compelled its adoption!

However, the steam locomotive, even including the largest sizes,
seemed to have reached the ultimate in all possible power
transportation possibilities, and yet it still failed to meet the
economies of the diesel-electric locomotive. This failure was due
to the fact that the diesel locomotive could make the most
efficient and unlimited use of the ‘length factor’ by
adding three, or a greater number, of diesel locomotives to a
single train all these added locomotives being under the management
of one engineer who could control their combined power to operate a
freight train over a mile long. It was this greater economy feature
of operation that sealed the doom of the old faithful and
dependable steam locomotive!

In closing, perhaps it would produce a more soothing alleviation
to digress abruptly from a trite mechanical theme and conclude with
a humanistic epitome. Conforming with this variation, I shall
relate a newspaper account of bits of conversation of a retired
steam locomotive engineer who was paying a last visit to his old
steam locomotive which was placed in line to be junked: ‘I used
to pet and pamper her as if she were alive. That’s the way I
always thought of her and the other steam locomotives. Each had a
feeling a personality that required a certain attention and
handling.’ Asked if he had a special pet name for his engine.
He answered, ‘No, we always referred to locomotives by their
number, but like I said, the steam ones were something
special.’ Referring to some nearby diesel locomotives, he
further commented, ‘The romance in railroading went out when
they came in. They’re just machines no personality, you
know!’