frame's
top rail, strengthen the frame laterally. Four of these rods can be seen
easily as they run from the frame to the middle of the boiler; the other
two are riveted to the underside of the boiler. The attachment of these
rods to the boiler was an undesirable practice, for the boiler shell
was thus subjected to the additional strain of the locomotive's
vibrations as it passed over the road. In later years, as locomotives
grew in size, this practice was avoided and frames were made
sufficiently strong to hold the engine's machinery in line without using
the boiler shell.

The front and rear frame beams are of flat iron plate bolted to the
frame. The rear beam had been pushed in during an accident, and instead
of its being replaced, another plate was riveted on and bent out in the
opposite direction to form a pocket for the rear coupling pin. Note that
there is no drawbar and that the coupler is merely bolted to the beams.
Since the engine only pulled light trains, the arrangement was
sufficiently strong.

RUNNING GEAR

The running gear is simply sprung with individual leaf springs for each
axle; it is not connected by equalizing levers. To find an American
locomotive not equipped with equalizers is surprising since they were
almost a necessity to produce a reasonably smooth ride on the rough
tracks of American railroads. Equalizers steadied the motion of the
engine by distributing the shock received by any one wheel or axle to
all the other wheels and axles so connected, thus minimizing the effects
of an uneven roadbed. The author believes that the _Pioneer_ is a
hard-riding engine.

The springs of the main drives are mounted in the usual fashion. The
rear boiler bracket (fig. 18) is slotted so that the spring hanger may
pass through for its connection with the frame. The spring of the
leading wheels is set at right angles to the frame (fig. 27) and bears
on a beam, fabricated of iron plate, which in turn bears on the journal
boxes. The springs of the trailing wheels are set parallel with the
frame and are mounted between the pedestal plates (fig. 18).

The center of the driving wheel is cast iron and has spokes of the old
rib pattern, which is a T in cross section, and was used previous to the
adoption of the hollow spoke wheel. In the mid-1830's Baldwin and others
used this rib-pattern style of wheel, except that the rib faced inside.
The present driving-wheel centers are unquestionably original. The
sist