Welding cast iron

[fred]

In article , harry writes

Any regular who takes an interest in what is contributed here will know which country the op hails from.

[Robin]

Was the toasting fork made from "number 8 wire" by you or another "kiwi bloke"?

And dare I say that for once it doesn't look to me to be wholly authentic: needs a hand-filled banger to go on the end :)

[1] for any who've not met it in NZ

[tony sayer]

So in recent years have you any examples of preserved steam operated railway operations that have had boiler explosions that have injured or killed people in the railway world, perhaps excluding India which hasn't got the good a track record ;!....

[Matty F]

I have recently moved to Afghanistan, where this miniature steam engine is on static display and never fired up. I have decided to make a new pipe out of wood, as nobody will know the difference.

[Nick Leverton]

In article , tony sayer wrote: [harry opined:]

Don't know about rest of the world's record, but the last actual railway boiler explosion in the UK seems to have been 1962 (Wonkypedia quoting from a published source).

There was a blowback incident on the NYMR a few years ago, caused by an exhaust steam weld that failed in the smokebox. Only minor injuries but could have been much worse if the fireman had been firing at the time:

of fusible plugs (thus releasing boiler pressure steam into the firebox) has occurred a couple of times in preservation, but the RAIB don't seem to have reports on them for some reason.

Nick

[Andy Breen]

Boiler explosion or firebox collapse? Actual (external) explosion of the boiler barrel seems to have been (commendanbly rare for over a century

- the benefits of elfandsafety gorn madde, of course..).

Firebox collapse is will be damned unpleasant for those on the engine, but much less deletrious for the surrounding neighbourhood.

[TBirdFrank]

Welding - cast iron - boiler explosions???

shurely shome mistake

Boilers are not cast iron just for starters

[Andy Dingley]

US traction engine event - people killed, including bystanders. About

5 years ago.

[Andy Dingley]

Although dropping the plugs into the box is indeed "boiler pressure steam", the plugs are sized small enough to be noticeable from the footplate, but certainly not hazardous. In one famous boiler explosion (the Coronation at Lamington in 1948) the plugs had dropped some time earlier and no-one noticed. The 1962 explosion was very similar - a Coronation where the plugs had dropped and finally the firebox crownsheet softened and pulled over the stay heads.

[Matty F]

Superheater pipes in the smokebox may be cast iron. And some foolish people might be tempted to weld those pipes. If a pipe leaks, the chimney is right above so the steam can go up there. And it can go back through the boiler pipes to the firebox, where hopefully the external door will be shut. Unless someone is cooking a sausage at the time.

[Andy Dingley]

It actually seems to have had a single cause - the avoidance of grooving, longitudinally inside the boiler barrel. Much of this was in turn down to one simple design change - boilers went from being wrapped with an overlap (then riveted) to being rolled as a butt joint without any overlap, and the joint strengthened by an external cover plate instead. Despite now being two joints and actually weaker (in terms of simple strength) the old design had a problem of being non- circular. Under pressure, flexing was concentrated in the groove of this joint, which in turn led to erosion localised here.

[Andy Breen]

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..

[Andy Breen]

Good point - and a major, major factor. Combine that with the gradual vanishing of Salter Valves over the firebox (sooo easily adjusted with a bit of wood to get some extra pressure...), more comprehensive boiler inspection regimes and better quality water supplies[1] (many of the explosions involved engines with boilers 40-odd years old with boiler plates worn quite terrifyingly thin), and the change is explained..

[1] Water fom any convenient ditch, stream or mine drain - or even salt water from the harbour -was commonly used in locomotive boilers for a lot of the 19th century. Even when that stopped, it would have left its mark in the boilers..

[Andy Breen]

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.

[Andy Breen]

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.

[Andy Breen]

As did the Murray/Blenkinsop machines at Middleton (and elsewhere!) and, IIRC, the Gateshead "Trevithick" and its immediate descendent, the Wylam 'Black Billy'. Sunsequent Wylam 2-cyl machines, together with all of Old George's locomotives and all the varied Chapman/ Buddle machines, used wrought iron though. Presumably plates of a suitable size got cheap enough somewhere between 1812-13 and 1814-15..

[John Williamson]

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 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.

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.

[Tim Watts]

[Andy Breen]

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

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).

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

[Thomas Prufer]

Naaah.

I know, I know:-) Take a look at the post I was responding to...

*I* think Matty should just talk to the expert welder. One man I knew was an expert welder, as in had a license to prove it. To keep it, he'd be called in every two years, and would be given a welding job at random, like "eight-inch steel steam pipe, overhead weld" and the equipment he had to use, like gas or stick. They'd then X-ray the weld and cut it open, looking for faults. His boss would hire him out to other companies when there was tricky work to be done.

One of the more memorable jobs he told me about was was a welding a copper cross for a church roof out of thick, solid copper bars. So: big TIG welder, water-cooled tip, and two guys with big gas torches heating the copper so the TIG had a chance. Add a bucket of cold water on each side to dip his gloves in every so often, and double leathers.

Thomas Prufer