BigBoy Power Reverse Gear Construction Photos Page 1
BigBoy Power Reverse
Construction Page 1 August 2004 - IN PROGRESS
The following are photos depicting the construction of the
BigBoy Alco Power Reverse Gear. This is a model of the Long Throw
variant of Alco's Reversing unit, used primarily on the Union
Pacific BigBoy as well as other large articulated locomotives
utilizing Walschaert's Valve Gear. The model is fully functional,
utilizing steam to complete the motion. It is modeled in 1.6"
click on any smaller picture
to view a larger picture
Boring the main guideways. The mount on the lathe needed
to be custom fabricated in order to hold the casting solidly enough
to achieve a consistent bore. This model is constructed utilizing
castings of the cylinder, cylinder head as well as main guideways
from David Moore.
After boring the guideways, they were mounted on an
arbor for further machining and holding in the Bridgeport. Here,
I am drilling mounting holes.
Drilling the anchoring holes to attached the cylinder
to the guideways in the Bridgeport
Boring the cylinder casting.
The completed cylinder in the background. In the foreground,
you can see a complete short throw variant of the Alco Power Reverse
The completed cylinder head, cylinder and guideway
(left to right)
Utilizing the small rotary table attachment for the
Bridgeport to machine the control valve. This part controls the
admission and cutoff of steam into the various ports of the valve
Here we see the completed Reverse Gear in the background,
the one I am in the process of machining in the forground in addition
to the main valve body, valve body head and packing gland. As
you will notice, the short throw variant of the Reverse Gear (background)
is substantially smaller, intended for small locomotives. In contrast,
the long throw variant (foreground) is intended for use mainly
on large locomotive, typically articulateds.
Here we see some of the many intricate parts needed
to be machined for the project. From left to right, we have the
valve body head, piston spring, control valve, control piston,
and main valve body with all the porting.
Again, a shot of the completed Reverse Gear, control
valve piston (shaft), control valve, and valve body
PLEASE CHECK BACK FREQUENTLY
AS MORE PHOTOS WILL BE POSTED AS MORE PARTS ARE MADE
AND THE PROJECT PROGRESSES TOWARDS COMPLETION