No original parts remain of one of the best known early locomotives, the
_Tom Thumb_. A full sized operable replica (figure 15), however, was
made in 1926 by the Baltimore and Ohio Railroad Co. for use in their
exhibit that year at the Philadelphia Sesqui-Centennial International
Exposition. It has since appeared at the Fair of the Iron Horse, held at
Halethorpe, near Baltimore, in the fall of 1927, the Chicago World’s
Fair in 1933 and 1934, the New York World’s Fair in 1939 and 1940, and
the Chicago Railroad Fair in 1948 and 1949. Its permanent home is in
Baltimore, at the Baltimore and Ohio Transportation Museum.
A small nonoperable model of the _Tom Thumb_, about 2 feet long (figure
16), made in the National Museum in 1890 (USNM 204581), is exhibited in
the collection of the Museum. Other small models of it appear in the B &
O Museum. One of these, a ¼-inch-scale model recently made under the
direction of Lawrence W. Sagle of the B & O Museum, differs somewhat
from the usually accepted idea of the _Tom Thumb_.
Notably, the smokestack is not straight, but has an elbow at its upper
end, and the belt-driven blower is located there rather than on the
floor of the machine as in the replica and the other models. Peter
Cooper, the New York engineer and inventor who constructed the original
_Tom Thumb_ as an experiment in the winter of 1829-1830, mentioned this
upper location of the blower in a speech delivered many years later, in
1875, and quoted in Bulletin 73 of the Railway and Locomotive Historical
Society (1948, pp. 50-52).
The little locomotive, with its vertical boiler made of rifle barrels,
looked rather like the larger locomotive of John Stevens of only several
years earlier but had considerably smaller wheels, these being only 30
inches in diameter.
Although a 3¼-inch bore for its vertical 1-cylinder engine is given by
most writers, Jonathan Knight, chief engineer of the Baltimore and Ohio,
in the fourth annual report of the company (for 1830, p. 35) gives the
figure as 3½. Unfortunately, he does not mention the stroke, which is
usually given elsewhere as either 14¼ or 14½ inches. The bore and stroke
of the replica were made 5 and 27 inches so as to give it sufficient
power to operate satisfactorily. For that matter, in the interest of
sturdiness and suitable operation the replica is somewhat larger in all
respects and considerably heavier than the original. It operates on a
steam pressure of 90 pounds per square inch, and it is reported that the
original did likewise.
[Illustration: Figure 15.—Full sized operable replica of Cooper’s
_Tom Thumb_, built in 1926 by Baltimore and Ohio Railroad Co. (PETER
COOPER’S “TOM THUMB” 1829-30 BALTIMORE & OHIO R.R.)]
[Illustration: Figure 16.—Model of _Tom Thumb_, in National Museum.]
The _Tom Thumb_ was engaged in its famous race with the horse-drawn
railroad car in the summer of 1830 on a parallel section of the new
13-mile stretch of track between Baltimore and Ellicott’s Mills. It
covered the 13 miles between the Mount Clare station and Ellicott’s
Mills in a little over an hour, and the return trip in 57 minutes. The
race with the horse-drawn car took place during the return trip. The
_Tom Thumb_ appeared to be a certain winner until temporary slipping of
the belt driving the blower caused the steam pressure to drop and
allowed the horse to become the victor.
Nevertheless, the _Tom Thumb_ by this and later trips in the same year
proved that steam locomotives were practicable, and caused the railroad
officials to announce on January 4, 1831, a proposed contest (to be
somewhat similar to the famous Rainhill Trials held in October 1829 in
England) in which the best locomotive demonstrated would be purchased by
the Baltimore and Ohio Rail Road Co. for the sum of $4,000.
The winner of this contest, the _York_, a vertical-boiler locomotive
built in early 1831 by Phineas Davis, a former watchmaker of York, Pa.,
is in the same category as the _Tom Thumb_, not only in that no original
parts survive, but also in that a full sized operable replica of it
(figure 17) has been constructed. This was built by the Baltimore and
Ohio in 1927 for use in the Fair of the Iron Horse. It also appeared at
the Chicago World’s Fair in 1933 and 1934, after which it was presented
to the Museum of Science and Industry at Chicago, where it has since
remained.
The original _York_ was used successfully on the run between Baltimore
and Ellicott’s Mills, and subsequently on the much longer run of some 40
miles between Baltimore and the inclined planes at Parr’s Ridge, on the
way to Frederick Town and Point of Rocks, Md. (Horse power was used to
raise the cars at Parr’s Ridge in 1832.)
[Illustration: Figure 17.—Full sized operable replica of Davis’
_York_, built in 1927 by Baltimore and Ohio Railroad Co. (YORK 1831
BALTIMORE & OHIO)]
As the first practical and generally serviceable locomotive of the early
Baltimore and Ohio Railroad, the _York_ influenced considerably the
design of the company’s subsequent locomotives. Within a year Davis had
constructed several locomotives of a generally similar design, all with
vertical boilers (see p. 47).
The _York_ had wheels 30 inches in diameter, weighed about 3½ tons, and
had a top speed of 30 miles an hour. Not long after its construction, it
was drastically altered in design and appearance. The vertical cylinders
were removed from the opposite sides of the boiler, where they had
operated the four wheels by means of direct-acting rods and trussed side
bars, and inclined adjacent cylinders were located behind the boiler,
where they operated by means of gearing on the rear axle only.
The modern replica, however, represents the _York_ as it was originally
designed and constructed. It operates on a steam pressure of 115 pounds
per square inch. The original is said to have operated on 100 pounds per
square inch, and it burned anthracite coal, a very early use of that
fuel in locomotives.