GW Railmotor Set
One of the most unusual Gauge 2 models is this electrically
driven Great Western Railmotor set, apparently dating from the
1920's.
See it running here:
The set consists of a power car with an apparently pre-Great War
field wound motor and a matching trailer car. The models do not
resemble any known prototype, appearing to pre-date the 1930's GW
diesel railcars and have the outline of 1920's Collett stock. This
suggests that they were made in the 1920's, later than most Gauge 2
models. It is toally unknown who built these models, but they are of
the same construction as the rake of 5 Collett style passenger
coaches purchased in the same auction in November, 2023.
All these models are unusual in having metal bodies which appear to
have been hand crafted from steel sheet. It's not clear how the
window openings were formed but a tremendous amount of work must
habeen involved. The models run on wooden underframes with bogies
fabricated from steel sheet. They are fully sprung with coil springs
bearing on compensating beams. The motor bogie is heavily built with
a complex gear train allowing power to be transmitted via the
central pivot.
The bogie mechanism transmits the power to the wheels using a bevel
gear and string of idlers and also carries a pair of roller pickups
that suggest that the model was built to operate on a line that had
two seperate power rails in the centre of the track.
The same arrangement can be seen on the unpowered bogie.
The motor is just as extraordinary as the model itself. It appears
from it's general design to date from before 1914 and is unusual in
being wound with 5 poles. This makes it a very nice slow runner, but
unfortunately it's not the best self-starter, typically needing
several sharp throttle openings to get going.
In operation, the Railmotor has a distinctly 'tramcar' sound. Today
it's driven by a pack of 4S 26650 Lipo cells, giving 16v with 5aH
capacity, enough to run the ancient motor for a couple of hours. The
motor is quite 'sparky' leading to glitching problems with modern
radio receivers and speed controllers, especially as the relatively
high voltage can destroy electronics intended for modern equipment.
In the end a combination of 2.4 Ghz radio with AFHDS2A protocol and
4S 20A speed controller has proved successful and the model has run
for an hour or more in one session. Click the picture below to see a
video of it in operation on a rather wet day in February, 2024,
perhaps 100 years after it was first made.:
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