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ATMOSPHERIC RAILWAY

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Originally appearing in Volume V02, Page 870 of the 1911 Encyclopedia Britannica.
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ATMOSPHERIC RAILWAY . About 1840-1845 See also:

great See also:interest was excited by a method of propelling railway trains through the agency of atmospheric pressure. Various inventors worked at the realization of this See also:idea. On the See also:system worked out in See also:England by See also:Jacob Samuda and S. Clegg, a continuous See also:pipe or See also:main was laid between the rails, and in it a partial vacuum was maintained by means of See also:air pumps. A See also:piston fitting closely in it was connected to the leading vehicle of the See also:train by an See also:iron See also:plate which passed through a See also:longitudinal groove or See also:aperture See also:running the whole length of the pipe. This aperture was covered by a See also:valve consisting of a continuous See also:strip of See also:leather, strengthened on each See also:side with iron plates; one edge was fastened, while the other was See also:free to rise, and was closed against a See also:composition of beeswax and See also:tallow placed in the groove, the See also:surface of which was slightly melted by a heater, carried on each train, in See also:order to secure an air-tight See also:joint. Connected behind the piston was a See also:frame carrying four wheels which lifted and sustained the continuous valve for a distance of about 15 ft. Thus the piston having atmospheric pressure on one side of it and a vacuum equal to 15 or 16 in. of See also:mercury on the other, was forced along the See also:tube, taking the train with it. Various advantages were claimed by the See also:advocates of the system, including cheapness of operation as compared with See also:steam locomotives, and safety from collision, because the main was divided into sections by separating valves and only one train could be in each See also:section at a given See also:time. It was installed on about 2 M. of See also:line between See also:Kingstown and See also:Dalkey (See also:Ireland) in 1843 and worked till 1855; it was also tried on the See also:London and See also:Croydon and on the See also:South See also:Devon lines, but was soon abandoned. The same principle' is applied in the system of pneumatic despatch (q.v.) to the transmission of small parcels in connexion with postal and See also:telegraph See also:work.

For further particulars see three papers by J. Samuda, P. W. See also:

Barlow and G. See also:Berkeley, with reports of the discussions upon them, in Proc. Inst. C.E., 1844 and 1845.

End of Article: ATMOSPHERIC RAILWAY

Additional information and Comments

The only book I know about this interesting old engineering/railway subject is "Atmospheric Railways" by Charles Hadfield. An excellent account.Mechanical details are sometimes a little obscure but can be deduced except for the section separating exit & entry valves of which there is no detail.As their duty would be extemely demanding I'd be most interested to get detail, pics,etc.....J.Mills
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