Mildred

Mildred was a GER Class A55. She served as the Main Antagonist in the series for like 3 episodes

Background:
The locomotive was built for purely political purposes in order to block the passage through Parliament of a new rival scheme for an electric railway. The Decapod was built in 1902 to a design by the GER Chief Draughtsman, Fred Russell under the supervision of the Chief Superintendent, James Holden. The aim was to demonstrate the ability of a steam locomotive to accelerate passenger trains at a rate comparable to electric traction and the electric trams with which the GER was also in competition over short distances.

The locomotive was far larger than any locomotive previously built in Britain for home service. It had 10 driving wheels for maximum grip and prevention of wheelspin, each of which was four-foot-six-inches in diameter which gave high tractive effort. Three cylinders were used because there was insufficient room for two cylinders large enough to develop the required tractive effort without going up to a higher boiler pressure. Even so, it still had to have a pressure of 200 psi (1,380 kPa) to achieve the required result.

Technical details:
The engine was fitted with a large Wootten firebox. There were three separate grates and ash pans, one on each side outside the frames and a third between, giving an aggregate area of 42 sq ft (3.90 m2). The trailing drivers were given a side play of 0.5 in (12.7 mm), the coupling rods being fitted with ball and socket joints. As the cranks of the three cylinders were set at 120 degrees in relation to each other, perfect balancing of the reciprocating parts was secured. In order to minimise the drivers slipping, compressed air sanders were fitted

VA:
Gingercat65