Vibratory-Piston Locomotives. |
Updated: 4 Mar 2014
Gallery opened: 17 Apr 2008
Lablache loco moved
A vibratory steam engine has vane pistons very like those of a rotary engine, but they oscillate back and forth rather than turning steadily; this was called the Cambrian sysytem. A connecting rod and crank will therefore be required to get rotary motion, with all the disadvantages of reciprocating masses that need balancing. The sealing problems are at least as severe as for the rotary engines.
The best-known vibratory steam locomotive built in Britain was the "Albion", an 0-4-2 built in 1848, for the South Yorkshire Railway. It appears that three tank-engines were built on the same basic system but details are scarce.
![]() | Left: A model vibratory steam locomotive.This is a demonstration model of an 0-4-0 based on the 1841 patent of John Jones, of Bristol, England. It is said to use the Cambrian drive system but is evidently not a replica of the Albion, as it has no trailing wheels. This model is in the Rahmi M Koc (?) museum in Istanbul, Turkey. How it got there is anybody's guess. |
![]() | Left: The "Albion" vibratory 0-4-2This is the "Albion", built by Thwaites Bros of the Vulcan Foundry in Bradford in 1848, for the South Yorkshire Railway. It is supposed to have run there for some 15 years, which would seem to indicate it was successful, though I strongly suspect it might have been converted to a conventional layout during that time. The transverse cylinder was fitted with "vibrating vane pistons" inside the drum between the two large wheels; these oscillated the central shaft. There appears to be conventional Stephenson valvegear just to the left of the central shaft. (arrowed)
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This locomotive was one of those featured in a well-known article "Curiosities of Locomotive Design" which was part of "The Development of the Locomotive Engine", by Angus Sinclair, in Railway and Locomotive Engineering for September-December, 1907. It seems very likely that this engine was built under the Cambrian patent, and this is now confirmed by the diary of David Joy, inventor of the Joy valve-gear.
The extract below is from The Diaries of David Joy, edited by G A Sekon, and published in Railway Magazine in 1908. (Volumes 22 & 23) The originals are held by the Science Museum.
May 1847
"We were asked at Railway Foundry to build this engine, and I got out a set of drawings for her, but when we got to the details of the vibrating pistons in their cylinders, the packings for these showed very slight chance of being made steam-tight, and E B Wilson & Co gave it up after I had worked out the question to exhaustion, and the manufacture was taken up by Messrs. Thwaites Bros, of Bradford. It was patented by John Jones, of Bristol, and called the "Cambrian" system."
THE LABLACHE LOCOMOTIVE
This locomotive previously exhibited here was not a vibratory-piston design, so it has been moved to the Lever-Driven Locomotive gallery.
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