Steam diesel hybrid locomotive
From Wikipedia, the free encyclopedia
A steam and diesel hybrid locomotive was a railway locomotive with a piston engine which could run on either steam from a boiler or diesel fuel. Examples were built in Britain, Russia and Italy but the relatively high cost of fuel oil meant that the designs were not pursued.
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[edit] The Kitson-Still locomotive
In 1926 Kitson and Company, Leeds, built an experimental example for the London and North Eastern Railway, using as their model the Still pattern engine already in use for stationary and marine applications. It was on trial until 1934, but then scrapped.
[edit] Construction
In outline the machine resembled a conventional 2-6-2T locomotive, but it had four pairs of horizontally opposed cylinders mounted longitudinally above the frame and driving a crankshaft placed between them. The cylinders were made double-ended, with one end of each cylinder for steam and the other fitted with a diesel injector. (Some drawings, published in contemporary magazines, show only two pairs of cylinders and it seems that this was one of the design features that was changed during development.) The boiler, with a diameter of only fifty-one inches (130 cm) and a small internal firebox, was mounted above. The driving position was in the usual place behind the boiler and tanks for fuel and water were mounted on the frames at the rear.
[edit] Operation
The sequence of operation was to heat the boiler in the normal way, but using fuel oil instead of coal. The start from rest would be made with steam power, but at about five mph (8 km/h) the diesel injectors would be started and the steam turned off. The waste heat from the cylinder jackets and diesel exhaust then maintained the boiler in steam for auxiliary functions (brakes and whistle) and in readiness to supplement the diesel power if required, or for the next start. By using steam for starting, no form of variable transmission was necessary and a permanent reduction geartrain of 1ยท878 to 1 ratio was fitted.
Overall power output did not compare well with conventional steam locomotives, although the performance on gradients was good because of the gearing. During the trials it was used successfully with coal trains and it proved very efficient in terms of fuel used, because the waste heat from the diesel power was recovered. However its running costs depended on the price differential between coal and oil and this was not favourable. When Kitson's failed in 1934 the LNER handed the machine back to the company's receivers and it was dismantled.
[edit] Other trials
Russia built three large experimental locomotives between 1939 and 1949. One used gas produced from anthracite to fuel its internal combustion cylinders and pulverised anthracite to heat the boiler. None of them was successful and they were converted to full steam operation after 1949.
[edit] References
- Atkins, Philip (1999): The golden age of steam locomotive building. Atlantic Transport Publishers, Penryn, Cornwall and the National Railway Museum. ISBN 0-906899-87-7.
- Ross, David(2003): The encyclopedia of trains and locomotives. Thunder Bay Press, Berkley, CA. ISBN 1-57145-971-5.
- LNER encyclopedia accessed 19 November 2006.
- Gallery of contemporary illustrations accessed 19 November 2006.
