On Thu, 25 Jun 2009 22:08:42 +0100, Steve Firth wrote:
Err well, let me see.

Steam engineering isn't difficult.
Tolerances are not particularly high.
There's a real danger that a modern steam train would be better designed
and built than what has gone before.

Yes, I suppose I was thinking along the lines of building to original spec
- not changing things like bearings to some uber-modern equivalent.

Enthusiasts working at the weekend perform every trade necessary.

I suspect all of those examples are ones that have far less hours of run
time than would have originally been the case, surely? (Hmm, although
aren't there still steam trains still in daily use in India?)

I'm not sure how well plans have survived - or how much was really
documented in steam's heyday (there seems to be a wealth of knowledge all
but forgotten about '60s and earlier IC engines, little tricks and tips
for repair and servicing that the modern generation simply don't know - is
that not the case with steam power?)

My experience of other technologies is that the theory survives pretty
well - but the practice just dies out for anything that's not in
widespread and frequent use.

modern steam engine has been built.

Indeed, but at enormous cost and with all sorts of modifications.
It'd be interesting to know how its price tag and build duration
stack up against its original counterparts - but that's just too much of
a vague question (counterparts would have been done with pre-existing
tooling in some cases, or from parts that had already been fabricated
etc., and steam power was once such an evolutionary process that I doubt
such thing as a "from-scratch build" has existed since the early 1900's)

How wrong are you determined to be?

Not determined at all; I'm not sure where you got that from :-)

But Tornado's the only example of a recent 'new' build I can think of; all
the rest have been restorations and are treated with very low running
hours (aside from the unconfirmed India cases).

I should maybe have phrased my question better as "can we build a
[reciprocating] steam engine any more with the uptime* and longevity of
the originals?"

* I wanted to say 'reliability', but that's not quite the same thing - I
expect the originals broke down all the time, but some oily worker
would just dive in and have everything running again very quickly.
These days it doubtless needs a huge committee, risk assessments, orders
put in for parts fabrication etc. :-)

Do you spend time outside Heathrow screaming that the aeroplanes
can't possibly fly?

Have you ever stood at the end of a major runway? Screaming anything
wouldn't get you very far

cheers

Jules