Simple steam engines and how steam engines work

[Deleted]

Trouble with Oscillating cylinders is that there has to be a compromise between the retaining spring pressure ( and therefore the frictional loading of the cylinder against it's parent block ) and the steam pressure needed to give the power required without forcing the cylinder away from it's block..

Having said all that, Brunel's Great Britain has a lovely pair of Oscilators which took her to Australia and back --- many a time >>>>>>>>>>> www.youtube.com/watch?v=TWrENdIu7mE

[steam4ian]

Joan

If you are looking for the most basic loco that has a proven record of doing work then Barry Potter's Blowfly is the most elegantly simple. See this link www.smex.net.au/Ads/01617/01617.php

Not the prettiest loco but that depends what you do with it. The design includes the minimum only required to get functioning loco. Simplicity features include, thick plate frames with no need to axle horns, welded connections of frames to draw beams and cross members, slip eccentric valve gear, boiler with round top, no waisting in of firebox sides and no superheat.

Sweat Pea is a pretty little loco with simple valve gear but the frame is so complicated compared to Blowfly. I am not sure Sweat Pea's marine type boiler is any easier to build except that is has minimal stays.

There is a prototype for a loco with oscillating cylinders. See figure 30 here www.catskillarchive.com/rrextra/odcuri.Html I am sure the retaining spring could be replaced by a balance piston working on steam pressure.

Food for thought.
Ian