Boiler safety issues

There has been an interesting discussion over on the Narrow Gauge Discussion Group in the U.S. https://ngdiscussion.net/phorum/read.php?1,420865
Apparently there has been a recent incident at the Cass Scenic RR where an employee was seriously injured as result of a washout plug blowing out as he tried to tighten it with an impact wrench whilst the engine was in steam. It seems that a similar incident occurred on the Cumbres & Toltec last year - fortunately without serious injury.
It is worth reading the advice from Kelly Anderson (the CME at Strasburg) which is equally applicable to the UK situation. What surprised me was Dan Markoff's (the well respected owner of Eureka) description of his recent FRA boiler inspection when the inspector only asked to inspect the plug/plug hole threads after the hydro. Apparently this was the first time it had ever been done! Any of the boiler inspectors I worked with always checked the plug threads and the fit of the mudhole doors at the annual dry inspection. Well worth a read IMO.
Ray.

 

Indeed. Some very good observations about 'Normalization of Deviance' (the mindset that led to the loss of the two NASA shuttles - 'it worked fine before').

Noel

 

Boiler safety.

FACT - Locomotive boilers contain a considerable amount of stored energy and can be extremely dangerous if not maintained and operated correctly.

The Heritage Railway Association (HRA) have made available numerous documents to help the heritage railway industry to operate safely. Those documents associated with locomotive boilers are under section 'B' of the 'Guidance Notes'. Any safety related guidance notes are available on-line to everyone, not just HRA members.

The particular guidance note on Washout Plugs (HGR-B9009-Is01-Washout Plugs) is available here: -

https://static1.squarespace.com/sta...1511179377505/HGR-B9009-Is01-WashoutPlugs.pdf

All locomotive owners/operators should ensure that anyone within their organisation who is involved with locomotive boilers has had the opportunity to read and can access the HRA guidance notes.

Andy.

 

Firstly, I hope they are ok/recovering.

Secondly, an impact wrench? Why? They only need to be tightened up by hand with an appropriate socket and t-bar. They need to be pretty snug and you need a good sized bar, but machine tools are not required. A machine just ups the chances you are going to strip those threads. An impact wrench is entirely the wrong tool for the job.

Next, on a live pressure vessel? Section 15 is exactly what I would expect to see.

Lastly. Any inspection I have witnessed has included plughole/mud-hole inspection as a matter of routine.

 

Scary stuff... Surprising that some of the American Types and the Bury Type actually stayed together (apart from one early in the film), considering their boilers were the mounting points for the axleboxes etc..

Does anyone know what the British Loco is at 1:11? Looks like an LNWR 0-6-0, did any have haycock fireboxes though?

Richard.

 

https://en.wikipedia.org/wiki/File:Boiler_explosion_1850.jpg

 

What is the one at 1.21

I do find group photos around the remains of a boiler interesting, but I guess it was a big event for those involved. Things change, I remember someone accidentally driving a loco off the end of a headshunt about 30 years ago and a photo of he and the fireman with the loco appearing in the magazine, only to be met by howls of anger about lack of professionalism. I wonder when it stopped being acceptable to have a group photo with the remains of an accident.

 

At 37 seconds in is 01.1516 at Bitterfeld, then East Germany in 1978(?). At least the 3rd such incident in that country.

 

Buxton, 11 November 1921.

 

Was that the one where following a boiler and fittings overhaul, that the safety valve wes assembled in such a way that it couldn't function?

 

Aha! Thank You Jim!

Richard.

 

Yes. Crewe had a backlog following WWI and sent some engines to outside contractors for overhaul . 'B' Class 0-8-0 Compound No. 134 went to Beardmore's, where the safety valves were given insufficient clearance between the moving parts. They worked when cold, but differential expansion prevented the valves' opening when hot. The boiler was estimated to have reached 600 p.s.i. before it exploded, three times its working pressure.

https://www.railwaysarchive.co.uk/documents/MoT_Buxton1921.pdf

 

Although the report's conclusion refers to the lack of clearance as the "main contributory cause", it also suggests that there may have been a number of other possible factors. Notably it places no blame on Beardmore's and ends "My general conclusion in this very serious case is that so many factors, some of them not necessarily constituting an element of danger in themselves, contributed to the result, that no responsibility can fairly, in the circumstances, be assigned to any individual."

By the way, @Eightpot may have been thinking of the 1909 explosion at Cardiff on the Rhymney Railway as described in 'Red for Danger', where the safety valves could not open at all due to being wrongly re-assembled, and the driver's report that he could not raise any pressure was because the needle had gone 'right round the clock' and was the wrong side of the zero stop.

 

I think I am right in saying that Buxton was the last example in the UK of a complete failure of the external structure of a boiler due to pressure. All subsequent "boiler explosions" in this country were firebox crown collapses.

Tom

 

Indeed it was.

 

I agree. Coincidentally I looked this one up easier this morning for a post somewhere else.
https://www.railwaysarchive.co.uk/documents/BoT_Cardiff1909.pdf
The gauge wasn't misread, unfortunately it was initially assumed the gauge was at fault. Tragically the boiler exploded and three men were killed while they were dropping the fire.

[Later] Interesting, reading the Buxton report, that a contributory factor to both accidents was that the crew assumed the gauge was misreading rather than the safety valves were faulty. I suppose it wasn't considered practical to give the crews two means of checking the pressure. Mind you I seem to recall a discussion on a firebox crown failure where having two means of checking water level didn't help.

 

From memory of reading the Buxton report, on some of those LNWR locos, the pressure gauge was directly attached to the boiler with no intermediate stop cock. Therefore, changing a pressure gauge could only be done by allowing the boiler to cool down (and then warm back up again afterwards) resulting in a considerable period out of traffic - there was thus a marked reluctance to check the calibration and perhaps therefore too ready an acceptance that the pressure gauge was faulty without rigourously confirming the fact.

Tom

 

While that is all true, Tom, the question is, how often do you need to change a pressure gauge?

 

Well, whenever you want to test its calibration? Thinking about a modern boiler test, don't you do the calibration of the safety valves using the boiler inspector's own calibrated pressure gauge - so the ability to swap them feels like it is a useful thing to be able to do?

(Or maybe turn it around - is there any particular reason, apart from cost saving, why it might be considered undesirable to be able to isolate the pressure gauge from the boiler? The most obvious I guess would be the risk that it would be indvertantly turned off, but you would very rapidly notice that when getting on the loco?)

Tom