|BUILDING A PLYWOOD GP35
MARCH 15-30, 2014
I had been thinking about buying or building a larger locomotive for several years. Prices being what they are, I figured it would be best to
build one instead of buying one. The basic body will be of 3/4 inch plywood, and the trucks will have mechanisms similar to those in my
smaller engines, each with a Ride Trains chassis using a 350-watt 24-volt motor driving both axles via chains. There is more room for
batteries, so we'll go with a pair of deep-cycle batteries. The basic locomotive is 16 inches wide and about 7 feet long.
Why a GP35? It's big (but not too big for the Calvert Central), its surfaces are flat and suitable for plywood construction, and hey, I've
always like the Reading GP35's. So we will make it a GP35 in a paint scheme similar to the Reading's but in Calvert Central colors.
PLANS AND DIMENSIONS
I found several sources for scale diagrams on the Internet by searching "EMD
GP35." I printed copies and converted measurements in millimeters from the
diagram into inches on the plywood model. For a reference, note that the
model's width is 16 inches and the axle spacing is 14.4 inches. For dimensions
of the cab and short hood I used a G scale GP40 to make measurements.
Using an Excel table, I entered the G scale dimensions in mm, then a second
column using the formula (G in mm)x29/2.54/7.5. This gives you the 1:7.5
scale dimensions in inches.
I'm using 3/4 inch plywood for the deck, body, and roof pieces. For the cab
sides and rear wall I'm using 1/2 inch plywood. For the cab's front wall (with 4
windows that are flush with the body) I'm using a piece of 1/4 inch Plexiglas
and will mask it during painting so I won't have to cut out the windows. The
hood sides are built from one piece of plywood all the way from front to back
with the cab area cut down to match the height of the bottom of the side
window. It took one sheet of plywood to do the deck, hood sides, end pieces,
and interior braces. It required part of a second piece to do the long-hood roof
and cab roof.