Boiler safety issues

Yes, the motion on 42500 appears to be set in mid-gear, but have the valves been set? I doubt it.

 

A couple of points here, in Tom's example 263 was pushed backwards and as it has a steam reverser, it may have been slightly in forward gear which you can't do anything about until you have about 60 psi. This would have pumped the boiler up as described.
Mid gear on a piston valve engine could be enough to pump it up. An engine will run in mid gear on lead steam. If you open the regulator in mid gear it can move off, you just don't get a say in which direction! Don't ask me how I know.
I've heard the whistle sounding on engines being shunted out of steam. The whistle valves sometimes drop open.
Funny things, steam engines.

 

Didn't We All? Have You tried a Sentinel?

I remember about 45 years ago there was a collection of Showmans Engines apparently being added to every week, at one time an unrestored Burrell Scenic was being towed cold to a rally (Burtonwood, Staffordshire?) by another similar engine, part of the route involved a long downhill stretch so the towed engine spent this part in low gear with the stick back, which pumped enough air into the boiler to have a good whistling session at the bottom of the hill. In the past I have wound Mamods backwards enough to pump them up to run forwards.

 

Only a Sentinel loco - but that was fun. I think you could be referring to Frank Lythgoe's collection of mostly showman's engines. He would likely be travelling from his base at Warburton to Burtonwood (Lancs) and the occasion you describe would be mid 70's and probably his Burrell SRL Dreadnought towing Dolphin.
Ray.

 

That sounds about right, I tend to post a bit ambiguiously in order not to tread on the toes of people that I don't know. Regarding Sentinels, replace the rails with a steering wheel about 2' diameter, and replace the brakes with, err with erm well nothing really, they are fun but in a 'to frightened not to be' sort of way.

 

Back in the 60's & 70's Middleton didn't have a loop at its depot and if the loco you wanted to use was behind another loco, a common means of solving the problem was to pump up the steam loco in front until you had about 30-40 psi in the boiler, that was enough to shunt it out of the way.
Even in mid gear a loco will pump slightly because of the lead of the valve. When moving locos, ideally you should drop the reverser into the direction of movement but you then have to remember to reverse it when the loco is reversed.

 

You're welcome to come and try it some day on a cold Chatham loco

Tom

 

I did say, 'ideally' but, if your locos aren't ideal, you obviously can't.

 

That's your footplate visit cancelled next time you visit the Bluebell! (If indeed they let you in at all)

 

Tom

 

I guess this is the same principle as the NER S3 counter-pressure test Loco?

Richard.

 

Some year ago I saw a boiler that had just had its out of frames hydraulic exam being warmed. The guy doing it said something along the lines of " I don't know why you guys take so long raising steam - I only lit up 20 minutes ago and already 20 psi on the clock." On checking he had not dropped the water level in the boiler to a suitable level! Luckily we got it rectified before any damage was caused.

 

Apparently this is a permissible method of doing a hydraulic test in the U.S. and they simply vent some water when at the desired max. pressure. It doesn't allow for much loss of water from the inevitable drips. Another difference there is that for any hydro it has to be done with warm water and max/min temps are specified in their regs.
Ray.

 

One of my first jobs on a loco 'at the tender age of 15 ,was to accompany a fitter on a dead loco from the loco shed to one of the quarries ,where there was ample tackle to lift anything on a loco. The tank and cab needed to come of. When we moved off ,the fitter put the engine in forward gear ,(we would be travelling in what should have been in reverse for a mile or so,) opened the regulator and shut the drain cocks. Oil had been tipped in the cylinders for good measure. On arrival the loco had about 35/ 50 pound on the clock enough to blow the whistle , much to the amusement of the men on the loco' pushing us. But the pressure didn't last long. Air had been sucked down the blast pipe ,and the pistons pumped it into the boiler, it was of course a slide valve engine. As far as steam pressure gauges, they are easily affected by frost ,must always be covered up if a loco is left out side in the winter, or better still taken off.

 

Dont know what happened here please click to expaned on above if intrested.

 

This is probably a good a place as any to post this. I stumbled across this on a French Steam Loco Facebook page - an article on a boiler explosion on 141.C-623 in 1937.

https://cheminot-transport.com/2022/04/explosion-de-la-chaudiere-de-la-141-c-623.html

In French but easily translatable into some sort of English, enough to get the gist of it. Interesting to see the calculations for how low the water ended up, and also how far the boiler went - 156m from the point of explosion to where it finally came to rest! Luckily only the crew were killed, and despite everything, the passengers got to Paris a mere three hours late.

 

Thanks for this. Translated quickly and easily on my iPad, liked that the French for crown sheet translated ‘the sky of the fireplace’!

 

It is interesting to see the forces at play in an instance like this of a catastrophic crown collapse. Because a boiler is not secured to the frames at the firebox end the firebox takes off vertically like a rocket, draging the rest of the boiler with it. Of course the smokebox end of the boiler is a bit reluctant to follow the firebox as it is secured, but not for long. Hence the typical cartwheeling of the boiler off into the surrounding countryside. This even happens in a couple of the huge post war US superpower boiler crown collapses where the boiler cartwheels off some considerable distance. In one of them it leaves the secured smokebox behind leaving the superheater elements largely in tact laid across the boilerless frames.

Scary stuff, eh?

Peter

 

Are you sure about that Peter? All the full size (and many live steam) loco boilers I've been involved with are restrained vertically whilst still allowing for fore and aft movement. The linked article explains how it is done https://books.google.im/books?id=NOfNAAAAMAAJ&pg=RA2-PA206&lpg=RA2-PA206&dq=steam+loco+boiler+expansion+brackets&source=bl&ots=--dQyLPhJL&sig=ACfU3U3OmirSypyYHCyvSiMtL-5HZYDKDQ&hl=en&sa=X&ved=2ahUKEwimlPaEv__2AhUFHuwKHXegCaoQ6AF6BAggEAM#v=onepage&q=steam loco boiler expansion brackets&f=false
Ray.