LONDON & CROYDON RAILWAY

ATMOSPHERIC RAILWAY

1845 - 1847

Jolly sailor railway station & pumping station, 1845

In 1845 an atmospheric railway was installed between (West) Croydon and Dartmouth Arms (Forest Hill). It used the method of atmospheric traction invented by gas engineer Samuel Clegg and the marine engineers Jacob and Joseph Samuda.

A large pipe was laid between the existing railway tracks. Three stationary engines positioned at Croydon (West), Jolly Sailor (Norwood Junction) and Dartmouth Road (Forest Hill) worked large air pumps which sucked the air out of the pipe in front of the train. The pump houses communicated with each other using Cooke & Wheatstone’s two-needle electric telegraph. 

At the Jolly Sailor needed to cross the London & Brighton Railway line. The atmospheric pipe made this impossible on the flat, and a flyover was constructed to enable the crossing: this was the first example in the railway world. 

Each train was headed by a special carriage which had an arm underneath which passed through a slot into the pipe. A piston was attached to the leading edge of the arm and a counterweight to the rear. The slot in the pipe was closed by a valve, formed of a leather strap covered with short plates of iron above and below. Wheels on the leading edge of the piston arm raised the valve, allowing the piston to move along the pipe. Air rushed in through this gap directly onto the back of the piston. The valve then fell back into place behind the piston arm and a wheel attached to one of the carriages pressed it down. On the opening side of the valve was a groove which was filled with a mixture of wax and tallow. A heated copper bar was then drawn along the groove to force this mixture against the edge of the valve and so form an airtight seal. The vacuum in front of the piston and atmospheric pressure behind it caused the train to move forward.

The advantages of the atmospheric system were that it didn’t need smelly, noisy and dirty locomotives to haul the carriages; it was considered safer - as two trains could not work simultaneously between two pumping stations there was no risk of collisions; and it was expected to be much cheaper to run.

The atmospheric railway called at Croydon (now West Croydon), Jolly Sailor (Norwood Junction), Annerley (now spelt Anerley), Penge (Penge West), Sydenham and Dartmouth Arms (Forest Hill) stations. This route was flat except for a wooden fly-over at Brighton Junction near Jolly Sailor (the first fly-over in the world). This was necessary because the atmospheric pipe couldn’t cross other lines on the same level.

The first trial was on 22nd August 1845. The train reached 60mph on that occasion and on a later trial achieved 70mph. However, failures occurred with the pumping equipment and the public opening was delayed until 19th January 1846. By December 1846 the atmospheric railway had been extended from Dartmouth Arms to New Cross, but the system was abandoned on the 4th May 1847 and the line changed over to locomotives.

There had been constant problems in maintaining the air-tight seals that were necessary to create the vacuum. In warm weather the mixture used to seal the valve melted and the leather hardened. In cold weather the leather cracked. Rubbish, including rats, were sucked through the pipes and clogged up the air valves. There were also delays in turnaround times at each end of the track. The piston carriage could not reverse and neither could the iron pipe cross other rails. So to get the piston carriage to the other end of the train it had to be manhandled out of the tube, have its piston and counter weight removed, then be taken round its train by further manhandling or possibly horse towing, have the piston and counterweight replaced the opposite way round and then re-inserted in the tube. The final straw was that, far from being cheaper, the power for the trains actually cost about three times more than conventional engines.