http://normsnotesnumber2.blogspot.co.uk/2012_05_01_archive.html
The station was closed but the thought of a Cream Tea Special pulling away from the platform sent a slight chill down my miserable old spine.
We went to have a look at the Newcomen engine house and were fortunate to coincide with a guided tour of the engine by a man (Peter Clayton) who had been involved in its partial restoration and had worked on it for over 30 years.
http://www.animatedengines.com/newcomen.html
This engine worked continuously from 1795 to 1921 and is the only one in the world still on its original site. There have been some slight modifications but the cylinder and pipe work seemed largely original. All parts were cast rather than machined and there was a raw beauty about the place.
The space was very cramped and the lens (Sony HX5V compact) not wide enough to take it all in. The cylinder is to the left and cold water was injected in to it from the valve in the bottom left. The restored (black) linkages synchronised the various parts of the cycle.
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The boilers are outside the engine house and steam was fed in to the bottom of the cylinder via this valve.
Steam pressure pushed the piston to the top of the cylinder then a jet of cold water condensed the steam and produced a partial vacuum. Atmospheric pressure forced the piston down to the bottom of the cylinder, so moving the beam and causing the other side to rise and pump water from the mine below.
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The engine originally used chains (as in the animation) but these were later replaced by rods using a Watt parallelogram linkage, which is hard to explain.
http://en.wikipedia.org/wiki/Watt's_linkage
The beam is pivoted on one wall of the engine house and the interior half moves up and down in a small second floor room.
When the engine last worked (in the 1950s) the operator lost control and it over stroked, causing the piston to crash in to the bottom of the cylinder and crack the foundations. Plans for the BBC to fund a restoration (as part of a programme about James Watt) were abandoned because of the Falklands War. However the Lottery has just awarded a grant to restore this engine but it is not clear whether this will return the engine to its original state i.e. using steam or whether the restoration would only enable the engine parts to move using an ancillary power source.
http://www.bbc.co.uk/news/uk-england-south-yorkshire-17389120
