The full size
locomotives upon which the above is based, were manufactured in the 1920's by
Metropolitan Vickers, they had a BO-BO wheel arrangement and were rated at 1200
HP. Only 20 were built and they ran between London and Rickmansworth on the London
Metropolitan line, they were replaced in the 1960's and there are only 2 surviving
in preservation, No.5 "John Hamden" and No. 12 "Sarah Siddons" They
were nicknamed "GROWLER", presumably due to the noise made by the transmission
gears. The locomotive is owned by John
Sibbles and was purchased 4 years ago from a member of Leyland Model Club. It
was built in 1989 by a Model Engineer from Skelmersdale and originally powered
by a 49cc TOMOS Moped engine, circa mid 1960's. Power
from the engine was transmitted to the wheels by a complicated system of chains,
sprockets, pulleys and belts. In view
of the age of the engine and the above drive system, the loco was not very reliable
and it was decided to convert it to electric power. The
work consisted of fitting four 12 volt 150 watt electric motors, these being controlled
by a 100 Amp Pulse Width Modulation Solid State Electronic Controller. Each motor
drives one axle, the motors are hung from the axles and the power is transmitted
to the wheels by means of reduction gears.
The loco is powered by two 12 Volt traction type sealed lead acid batteries. The
modification has proved very successful and the model is a regular "passenger
puller" on its home track at Sale in Cheshire. The
Motors, Gears and Electronic Controller have been supplied by Messrs. Parkside
Electronics, Valley Mills, Southfield Street, Nelson, Lancs, BB9 0LD, Tel. 0870
908 9373 whose assistance in this project is gratefully recognised.
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