Stuart McIntosh from Australia commented: “Higher boiler pressure must mean a smaller (lighter) piston disc and less unbalanced mass and reduced hammer blow. Efficiency would also be increased.” Chris Newman’s replied to say: “Higher boiler pressure would provide all sorts of benefits, not least being higher efficiency. And you’re right too that it would mean […]
Why not adopt a higher boiler pressure?
Q: One very common traditional means of delivering feed water to a boiler was through a clack-valve on the back plate and along a pipe past the firebox to the front end of the boiler. Does this arrangement act as a basic form of preheating as the feed water passes the firebox end of the […]
In Feb 2017, Chris Newman wrote to David Wardale to ask if there was any justification in the suggestion that the predicted evaporation rate for the 5AT of 17,000 kg/h might be unrealstically high, particularly with coal-firing. He pointed out that in lines  and  of FDC 1.3F a maximum specific burning rate for […]
The following comes from a “Is it just a Phantom” – David Wardale’s response to Herr Ebel published in Lok Report in March 2001: “The proposed working pressure of 21 bar is less than the maximum successfully used in America, and the normal nature of train operation will give a mean boiler stress significantly less […]
The following answer is taken from Wardale’s response to an unpublished letter from Bryan Attewell written in response to Wardale’s two-part article “Steaming into the Future” published in Steam Railway magazines #272 and #273 (see ‘Articles and Letters’ page of this website): “Mr Attewell would like a larger boiler, but what counts most for steam […]