Great video, thanks for such a good explanation. I've been visiting the Science Museum for over 50 years and had always assumed that this engine ran on compressed air. I had no idea that you were actually generating steam to run it!
Lovely to see the engine running again. Was always my favourite part of the museum as a kid to see all the different engines running. When is the engine run these days as the last couple of times I have been none of them have been running and it does make power room feel very dead without them moving.
I'm surprised that they are still using steam to run it. Most steam museums use compressed air to operate steam engines anymore because it reduces a lot of the equipment required to run it. No boiler, condensor and associated pipework. It also eliminates the possibility of boiler explosion or the potential for fire. All you need is an electric motor and a rotary scroll type air compressor to make the pistons move. It reduces the tendency for the water to rust out all those components also.
Those beautiful works of art, as much as I love big old engines, almost caused the extinction of a species. The belts that ran individual machines used, because it was tougher and lasted longer, the leather of the American Bison. US and Britain used a LOT of leather.
so do you pre warm the engine before running or just get the boiler up to pressure and then run the engine from cold. to be honest its really bad practice if that is the case I've been in charge of and run quite a few mill engines and we always pre warm the engine to reduce the risk of condense in the cylinders as water doesn't compress does it and gives a very real possibility of blowing a cylinder end cover if the water cant drain out quick enough.
