LS Thomas-pix

[Dave]

Cylinders were mounted under the smoke box and linked to the middle axle which was in fact a crankshaft similar to an Automobile Engine. Valve gear ran on the same axle on concentrics. All hidden away but a real terror to grease and oil.

[calenelson]

lots of Thomas stuff here!

http://www.pegnsean.net/~railwayseries/thomas.htm

cale

[Alex Butner]

Wouldn't the configuration of a British steam locomotive be similar to a Heisler?

[andyb]

Wouldn't the configuration of a British steam locomotive be similar to a Heisler?

Well, as I understand it, the cylinders on a Heisler are at right angles to the loco and in opposition to each other.

On an inside cylindered British loco, the cylinder(s) are in line with the loco ie point front to rear, parallel with the boiler, and if there are more than one, are side by side, between the loco frames.

Also on British steam locos the inside valve gear is usually of the Stephenson type, although Joy valve gear has also been used esp on the former London & NW Rly. Sir Nigel Gresley used conjugated valve gear on his V2 class 3 cylinder locos and the sole 3-cylinder 8P Class Pacific 'Duke of Gloucester' uses British Caprotti valve gear.

So plenty of variations here!

btw - there is a 'real' Thomas still extant on the Nene Valley Railway, near Peterborough, Cambridgeshire, UK. It was named by the Rev W Awdry (who I met on a couple of occasions). It is an 0-6-0 but with outside cylinders unlike the Thomas in the books and was manufactured by the Hudswell Clarke loco company in 1947.

There's a picture of the Revd naming Thomas on the nene Valley Railway's website( http://www.nvr.org.uk/thomas/):

http://www.nvr.org.uk/thomas/tbsc01.jpg

You can see the outside cylinders in this picture (below), also the cutouts under the side tanks to access various bits under the boiler, but otherwise pretty near to the 'real thing'!

http://www.nvr.org.uk/images/Thomas.jpg