On Fri, 15 Jul 2011 12:12:23 -0700, Andy Dingley wrote:

On Jul 15, 2:12Â*pm, Andy Breen wrote:

Except there were. Only in the early days, I'd admit, but the first
commercially successful locomotives (and the first locomotives to be
built as more than prototypes, and the first exported..) had cast-iron
boilers.

Which ones? Most of Trevithick's had cast iron shells (still with a
wrought iron endplate), but I can't think of any others, or of any
"first exports" (which one?)

The Murray/Blenkinsop machines, one of which was exported to Germany (and
another one built there). Both the German examples had cast boilers,
as did at least the first pair of machines at Middleton. At least one
of the later Middleton machines had a wrought iron boiler. I'm not
sure if there is any evidence one way or another for the ones used
at Coxlodge, and the Nant-y-Glo machine is distinctly obscure.

that were cast iron. Certainly the Tyneside
builders were using wrought iron from the outset - although they still
managed to have boiler explosions, including Locomotion itself.

Pearce contends that Locomotion underwent a flue tube collapse - much less
dramatic - and the boiler barrel explosion was another locomotive of
the initial 5 built.

There is some possibility that Brunton's Mechanical Traveller (the one
with the walking legs) was built with a cast boiler, but it had been
fitted with a wrought iron boiler just before it was destroyed by a
boiler explosion.

The Brunton machine used at Crich certainly seems to have had a cast boiler.
The second(?) one may well have done so before being reboilered.

--
From the Model M of Andy Breen, speaking only for himself