James Sim’s had several connections with William West, and their relationship was a mixed one. As seen in an earlier post, he was one of the most vocal of the Austen’s Engine trial critics. He would became related to West through marriage, when he William married his sister, Grace Sims.
The West-Sims business relationship would in time evolve from bitter rivalry into a working partnership. In 1843 the Sims family granted West the licence to build the Sims compound engine, and West installed several large engines of this design in Devon and Cornwall.
Jame’s engine was developed in the late 1830s. It used two cylinders one above the other; the smaller higher pressure cylinder sat on top of the larger lower pressure cylinder. The design was attempt to reduce the ‘kick’ being induced by using higher pressure steam. Unfortunately it required a taller, and therefore more expensive engine house, in addition to being difficult to maintain as a result of steam packing gland located deep within the engine, between the two cylinders. It was not a design that was widely adopted, although it did form the basis of the huge dutch engines at Cruiquis.
I have been hunting the web for a good picture of the design, as so far this is the best I can discover. A cover of a book for sale at Plough books. Feel free to comment if you have stumbled across others. The Cruquis museum on their excellent website has a diagram and description of its operation.
This is the best I have managed with the book cover, not a good image I admit. It does show well the overall layout however, and more importantly, the impact its design had on the engine house. Having the high pressure cylinder stacked on top would have demanded a significantly taller building.
If you do know of some better images of this type of compound engines please post a message, I am sure there must be some better ones out there. Meanwhile the preparation for the Luxulyan valley talk continues….jm