Reynolds Corliss Steam Engine -- By Mike Dennis




Reference Material


Construction Notes


About the Model:

Designed and Built By Mike Dennis August/September 1999
Modified September 2005
Member - H.T.M.C.,R.M.G.
Approximate scale 1/6


The main reason for making this particular model is to demonstrate Corliss valve operation which uses Mecarep Micro system parts involving the use of 8.B.A. threads 1/8" Wide collars and 3/32" Dia brass rods. Whenever the engine is displayed I am accused of using too much model engineering which tells me I have achieved the main objective of model engineering WITH Meccano! The system must be allowed continuous development just as in real life. The company is so arrogant that it has never in its history catered for enthusiasts or listened to model engineers who use it and their development record is appalling.

The model was built using the only references I have which are the two engravings shown in the reference material, some valve diagrams in the Joshua Rose book 'Modern steam engines' originally published in 1887 - Drawings 1 - 4 refer, and details of the Reynolds trip gear in the book 'Corliss, Man and engine, by William D Sawyer shown which is shown on here. The engine ran at around 100-120 RPM on about 60 PSI steam pressure which was fairly typical of all Corliss valved horizontal engines although they are known to have run efficiently at speeds of up to 160-180 RPM. The model runs more slowly to allow viewers to watch the wrist plate, valve, governor and dashpot control rod movements. I have not modelled fully working trip gear but the dash pots are timed and triggered by Meccano metal spring clips. Please note that the above notes and drawings are provided for the model maker to interpret the model to their choice. Model engineers will make their own decisions as to the methods and materials used.

This engine would have insulted the original and looked hideously out of proportion if only Meccano parts had been used, especially for the valve and governor control rods and other parts at this scale. I could certainly not have afforded to build it to a large enough scale to use all Meccano and it would probably not have fitted in my bungalow without causing 'world war three' with 'she who must be obeyed'!

There are no short narrow cranks, 3/32" rods or narrow collars in the system and neither are there any parts I considered suitable for the connecting rod, cross head assembly and slides. I use Meccano parts and David Fellows or Ashok's alternatives wherever and whenever I think they are appropriate because Meccano have refused to develop certain parts which their systems provide but as my models are always described as made WITH Meccano and I never enter any competitions I do things MY WAY by the Frank Sinatra method.

The model was included in the ISSES (International Stationary Steam Engine Society) bulletin Vol. 21 No 4 which is an achievement because the society usually publishes only historical articles and live steam matters.

Edwin Reynolds

Edwin Reynolds was the virtual successor to George H. Corliss in steam engine design. His trip gear was the most popular in use after 1890 and the company he joined in 1877, E.P. Allis and its successor, the Allis Chalmers Company had built over 6000 engines by 1914. Reynolds was born into a large farming family in Mansfield, Connecticut, U.S.A. on March 23rd 1831. After leaving school at 16 he served a 3 year apprenticeship in a small country machine shop where he learned to use 'initiative' as the equipment and tools were not very good! Around 1850 he joined the Woodruff and Beech ironworks in Hartford , Connecticut, until 1857 when he moved to the Mid West to join Stedman and Co, in Aurora, Indiana, where he was eventually appointed superintendent. He left and joined Corliss in 1867 as a salesman and engineer becoming general manager in 1871 but his talent was stifled by George Corliss, who still controlled design. In 1877 he left to join E.P. Allis and Co, in Milwaukee, Wisconsin, who were a struggling small company employing 150 people. He received less salary but had a free rein for his talents, and saw the wider market potential for steam engines in the Mid West due to greater concentration of business and a growing number of industries.

Reynolds Corliss

The first Reynolds engine was a single cylinder horizontal engine with 14" bore x 36" stroke and was built in 1878. By 1895 E.P.Allis had built 500 and by 1897 the figure was well over 3000. These engines were equipped with Reynolds patented trip gear, which, with its compactness, simplicity, and suitability became the most popular type of trip gear used on Corliss engines. Other advantages were that its parts all hung on the valve stems and bonnets. It was safer regarding 'runaways' (tendency of the valves to go out of phase) and ran more efficiently and quietly at higher speeds than earlier designs.


Questions about this model?

Contact Mike Dennis

Email >>