On Fri, 15 Jul 2011 15:17:08 +0100, John Williamson wrote:

Andy Breen wrote:
On Fri, 15 Jul 2011 06:12:52 -0700, harry wrote:

On Jul 15, 1:54 pm, Andy Breen wrote:
On Fri, 15 Jul 2011 05:05:17 -0700, Matty F wrote:
shurely shome mistake
Boilers are not cast iron just for starters
Not (usually..[1]) in locomotive applications for many years, but it
was the standard material for many boilers - including locomotive
ones back in the earlies.

The first commercially successful locomotives - and the first
exported - had cast iron boilers, after all..

[1] Does the replica of the Gateshead machine that masquerades as the
Pen-y-Darren machine have a cast boiler? Trevithick certainly used
'em..

I think you will find they were wrought iron for many years. Merthry
Tydfil was renouned for it's wrought iron.


Coalbrookdale, OTOH, was a specialist in casting. Pretty sure the
Trevithick stationary engine in the Sci. Mus. - that kissing-cousin of
Catch Me Who Can - has a cast boiler.


Don't forget that when that was designed, 10 psi was an amazingly high
boiler pressure. The replica of Stephenson's Locomotion on the Waggonway

Except for Trevithick and his followers, for whom 50psi was
normal (the Pen-y_darren and Gateshead machines worked at 50psi,
as did CMWC)/

at Beamish has a modern boiler made of modern materials but looks like
the old design, and runs at twice the original pressure. Its safety
valve is set to blow at 15 psi.

Locomotion, like the rest of Stephenson's machines, was designed to work
at 50psi. In normal use, the safety valve was tied down when the engine
was moving and only released at standstill (pretty well universal practice
pre-1828-ish).

As far as I know, locomotives all had wrought iron boiler barrels from
the earliest days, with stationary engines using cast iron for parts of
theirs. Then again, early stationary engines normally ran at a maximum
of about 3 or 4 psi.

Except, as I say, for Trevithick and the users of his patents.
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