LOCOMOTIVE ENGINE.
463
so as to pull without side strain when the height is altered from the use of another
tender or other cause. The draw links W'W' are left free to move in any direction,
in order to allow for the play of the springs of the engine and tender, and the oblique
direction of the pulling round a curve; when they are disconnected from the tender
they can also drop down upon the edge of the plate V\ The draw-pin V' is re
quired to be strong to resist the great strain to which it is subjected; it is most
strained when running down a considerable inclination, as the engine is not then
constantly pulling, but the train often pushes against it, and a continued succession of
violent jerks on the pin are produced in opposite directions ; instances have occurred
of the draw-pin breaking under these circumstances in engines where it was not
made strong enough for its length.
Splashers, d" d", are fixed over each of the wheels to catch the dirt thrown up b}^
them ; those for the middle wheels are of brass and are ornamented, the others of
sheet iron, and they are fixed by small stays on to the boiler and the outside
frame.
Inside Frames.—Four wrought iron frames, Y' Y', (Plates XC. and XCI.,) are
fixed between the smoke-box and fire-box; to afford additional strength to the engine
by securing firmly the back plate of the smoke-box, in which the cylinders are fixed,
and which has to bear the whole strain of the working of the engine. These inside
frames have also bearings in them for the cranked axle, and hold it steadily against
the action of the connecting rods, by which it is strained alternately in opposite
directions. The frames Y' Y' are 3-^ inches deep, and three quarters of an inch
thick; they are attached to the smoke-box and fire-box by means of T shaped pieces
of iron, which are riveted on to their inner and side plates, and are bolted to the
ends of the frames ; the two middle frames are made to approach each other, and are
welded together at the back end, so that there are only three bearings on the cranked
axle. On to the four frames are fixed the piston rod guides, A' A', by means of
pieces of angle iron, as before explained. The frames have to be inclined upwards
towards the fire-box, in order to pass above the cranked axle.
The construction of the inside bearings of the cranked axle is shown in figs. 41,
42, 43, and 44, to double the scale, or 1^ inch to the foot. Figs. 41 and 42 are
side and end elevations; fig. 43 is a horizontal section through the centre of the
bearing; and fig. 44, a plan of the top. The frame, A A, is increased at the bearing
to 2^ inches thick, the upper part, JB, is 11^- inches wide, and the lower part is
formed into a fork, C C, 10 inches long, the sides tapering an inch and a quarter in
width. A tube, D D,' is fitted between them, having a bolt passed through, it by
means of which the two sides of the fork are held firmly together. Two iron
wedges, E E, are fitted accurately to the sides, so that their inner faces are parallel