Hush-hush

[Aussiesteamer]

Hi forums, Iv been looking into the W1 lately and Iv been stuck on this for some time now as there's almost no information on it whatsoever. How did the W1's firebox work? As one can imagine it couldn't have been like traditional firebox's and most diagrams Iv found show no signs of a 'normal' firebox as one would see on a Average steamer such as a LNER A3, if anyone out there knows how the W1's firebox was set up within the locomotive or has any pictures or diagrams of it it'd be greatly useful

[teaky]

I recommend you get hold of a copy of "Hush-Hush: the story of LNER 10000" by William Brown.

[Hatfield Shed]

As a 'starter' to give you an idea, the firebox grate and ashpan beneath were much as on a conventional loco boiler. But everything else then until we reach the chimney is different. The grate and combustion chamber is in a firebrick lined shell, rather than a water jacketed firebox. The water to be heated is in many vertical ranks of tubes (it is a 'water tube' boiler) densely packed inside the shell, with the firebox gas circulating around them; the tubes connected at bottom to two water drums and to a large pressure vessel at top centre, a steam collector. The superheater elements are also in the combustion gas space.

The water tube boiler is standard for steam generating plant in coal and oil fired power stations, and typically cuboid externally, rather than the cylindrical boiler form we are used to on the steam loco. It is interesting to note that several attempts around the world to exploit the water tube boiler on steam locos failed. The size and shape constraints, and difficulties with leaks caused by the vibrational environment figure heavily. The original Hush-Hush boiler was used as static steam raising plant at Darlington until 1966, suggesting that other than coping with the vibrational environment, the basic design was sound enough.

[Aussiesteamer]

Thanks they're both really good starters. Iv looked into the book and it's proving greatly useful. 'Hatfield shed' not trying to ask to much but if you have any more information it'd be brilliant!

Kaleb

[Hatfield Shed]

Here's a decent introductory from one of the major businesses specialising in such things. http://www.babcock.com/library/Documents/e1013155.pdf

I first became acquainted with this boiler design for process steam supply. When employed in static plant it is possible to use a layout that works with the natural convection of heated fluids. This is one advantage largely lost in the locomotive format, along with the heat scavenging techniques that are relatively easily employed where there are not the significant weight and volume restrictions of a railway vehicle.

All that said, technical advance in making this steam raising plant more compact has moved matters on. A water tube boilered steam turbine-electric Beyer Garratt arrangement doesn't look beyond the realms of possibility now, as a long distance freight mover for coal mine to power plant hauls. Turbine generator set on a bogie vehicle one end, fuel handling, water and condensor on a bogie vehicle the other end; boiler unit slung between making full use of the loading gauge. Potentially avoids the large cost of the OHLE alternative, when oil price increases push diesel out of this traction role.