The Dividing Machine: An Invention by William Stanley
In 1845 the London and Croydon Railway opened an atmospheric railway, which used air pressure to move trains.
The line ran from West Croydon to Forest Hill. Pumping stations were established at West Croydon, Portland Road (now Norwood Junction) and Dartmouth Road (Forest Hill). The pumping station (at Norwood) was built in high Gothic style, and had a prominent tower which was both a chimney and a vent for air pumped from the tube.
Steam engines at these pumping stations created a vacuum in a pipe laid between the rails. A free piston in the pipe was attached to the train through a slit sealed by a leather flap. The piston, with a train attached, was pushed from one pumping station to the next by atmospheric pressure.
Unfortunately the atmospheric railway did not prove a success: the air pressure was not able to be maintained and there are contemporary accounts of passengers having to get out and push the trains – sometimes pushing so hard that the train ran off at great speed and they were unable to re-board!
The main problem was with the valve flaps which were leaky – in part due to rats developing a taste for the tallow which was used to maintain the seal. Part of one of the 15 inch atmospheric pipes is on show at the Croydon Museum, together with a wind-up model of the railway.