Science Fair Project Encyclopedia
An atmospheric railway is a railway in which air pressure or vacuum is used to drive trains. The best known attempt was that by Brunel in the 19th century on a 52-mile section of the South Devon Railway between Exeter and Plymouth, England. It was also tried on the London & Croydon Railway in 1845, but was soon abolished.
The supposed advantage of the atmospheric system was its hillclimbing ability; however Brunel chose to test the system on a relatively flat section. Brunel did however assume that the system would work, because the mainline to Cornwall was designed to contain some very challenging gradients of up to 1 in 38.
The atmospheric system proved to be a complete disaster:
- the seals on the tube failed - amongst other reasons, rats liked to eat the sealing grease.
- shunting the trains into atmospheric formation was a nuisance.
- the pump stations every few kilometres has to be run continously and were expensive.
- as mentioned above the hillclimbing abilities of the system were not put to the test.
- it is not clear how atmospheric railway tubes could be compatible with railway turnouts.
- telegraphy may not have been advanced enough to co-ordinate the pump stations and trains properly.
- Cable railway - a more successful albeit slow way of overcoming steep grades.
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