a few years ago there were a couple of boiler "pops" I would say on a couple of lines, I don't recall where who, someone might, it was newsed in one of the railroad mags, Trains or Railroad. The last thing we need on a tourist line is an old fashioned boiler explosion. Not too long ago a steam traction engine blew up. An old story I heard/read, some engineer was tired of hearing the pop valve going off so he tied it down....KABOOM!!

What I hope is your friend operators are right, its only the superheater, but put the engine down, and take care of it.

You know, we have now gone from calling 911 in a breathless panic to to citing the historic Best Friend of Charleston story. I respectfully request that if posters don't know what they are talking about, restrain yourselves and don't post.

The original question deserved a well considered answer, and could have been the basis for some well reasoned discussion. Some of that has appeared, from people of authority in the industry who are responsible for managing this sort of situation, but it is getting lost in the unfavorable signal to noise ratio.

My initial advice was based on quite sketchy initial information, missing information included;

Missing Info #1 - Location of said pressurized boiler showing signs of possible (not certain, but possible) rupture;

1 - If parked in an empty corn field with no one around for a few miles; just walk (briskly) away and come back tomorrow to effect repairs or pick up the pieces, which ever applies.

2 - If parked next to a high density apartment building (common in European cites) with lots of glass windows facing the boiler a prudent call MIGHT be to evacuate the building as a common sense precaution.

I did say MAYBE you should call for more help until the situation is better understood.

Missing Info #2 - Nature of the water source extinguishing part of the fire (now better understood as a flue to sheet joint leak). In my defense the original post said (IIRC): "I can't tell where the water is coming from". Someone did say they "thought" it was a tube leak, but it was unclear how certain that info was.

1 - Yes it could be ONLY a joint, or a cracked flue that might collapse, but again knowing where the boiler is located makes a difference, if its near a crowded park or downtown area I don't think evacuating the area around the locomotive (with help from emergency personnel if helpful) would be unwarranted.

2 - Given the original lack of detailed info a cracked flue sheet (less likely, but not impossible) would warrant a more urgent response, as would a possible cracked superheater manifold casting (less likely, but not impossible) which could fail and rip the front flue sheet causing the pressure vessel to fail.

Given the original spotty information I was acting with utmost caution in my offered advice. Not knowing for certain that it was a tube to facesheet leak means one should assume the worst case and respond as appropriate given the local conditions. A large enough leak to effect the ability to keep the fire burning in spots COULD easily be more than a flue to facesheet joint and could be much more dangerous. Better to be safe and get this boiler in a safe condition ASAP.

Opening the blowdown valve periodically on a standing locomotive with no train attached is probably as reasonable an option as possible without something to keep the engine in place (a stout bumper post or a good size string of cars with firmly applied brakes). A fully opened throttle could easily override some loco brakes and then you have a moving boiler that may rupture. If it is standing you could easily open the blowdown occasionally and get the thing depressurized fairly quickly (an hour or so). The pressure is the risk, not the temperature, if there is a crack it's propensity to propagate is not much affected by a 50 or 100 degree temperature difference (the strength of the material is very nearly the same with that small of a temperature difference). But a 50 PSI lower pressure will reduce the risk MUCH more (the stress applied to a possibly cracked component is very much affected by the pressure).

Regarding firefighters destroying a historic artifact, I personally would never put the safety of ANY piece of equipment ABOVE the safety of the public or the volunteers. Yes, some of this equipment is irreplaceable, but so are individual people to those that know them.

And going forward you might want to consider inviting the fire department over to your place of business and giving them an education about the nature of the risks involved so they know how to react properly, they would surely appreciate that.

Overreact ? Perhaps, but being a continent (and several time zones away) I do not regret in any way my advice to cool this boiler and depressurize it as quickly and safely as possible (even if it caused some additional repairs going forward). And to use emergency services to protect the public (if deemed necessary based on local conditions I had no way of knowing at the time).

My father was a steam qualified engineer for the NYC and I can assure you that he would reject any engine offered him at an engine terminal with enough leaks in the firebox to affect the fire. And if leaks that bad developed in route he would surely have stopped the train at the next terminal and had the engine replaced. And I am sure the Road Foreman of Engines would have backed him fully.

A crew on the NYC lost a flue on a NIAGARA (a well maintained state of the art machine) at full track speed (80mph) and full pressure; the fireman opened the grates, the engineer pulled the throttle wide open to depressurize the boiler as quickly as possible, THEN he applied the emergency brake, THEN he and the fireman hung from the the engine steps and unloaded from the cab as soon as the train stopped (and chained the engine drivers since without steam they would soon lose airbrakes). A quick decision to fully open the throttle and depressurize the boiler (and reduce the chances of additional damage) probably saved their lives (and possibly some riders lives), sure the engine may have been damaged, but they retired after a long career.

I don't ever remember many folks complaining about calling the Police/Fire Department TOO SOON, but lots of regrets about waiting TOO LONG to call them...

Overreact or not, this engine needs to be out of service UNTIL the real cause is ascertained without doubt and properly corrected. If I read the string of posts correctly these tubes have been rolled and re-rolled and there is still a significant enough leak to put parts of the fire out. In my opinion if you have rolled these tubes multiple times and there is still a large leak you have a serious problem some place (assembly procedures, material quality, too much quick warm up/cool-down, corrosion/water treatment, etc.). There may just be another source of the leak hiding (a crack someplace) to show up unexpectedly. A crack can also get better/worse (wider/smaller) with the addition of hot/cool air until the crack goes all the way....

I still recommend this unit be out of service until this is properly debugged and corrected regardless of the effects on your schedule.

Cheers, I am glad everything worked out safely for everybody involved, Kevin.

With a copper firebox the smoke tubes are expanded into the firebox tubeplate and then beaded over. Superheater flues are screwed into the tubeplate.
Going back to the original question. Were it me (and I've been involved with loco-type boilers of various sizes for getting on for 50 yrs) I'd have simply closed the dampers and firehole doors, turned off the blower and filled up the boiler. The fire would die and the boiler cool naturally - no panic (Kevin please note).
Had it been just a smoke tube, once cool, I would have plugged it with a pair of tapered plugs and drawbar but as it's a superheater flue I wouldn't mess with it. Some years ago a superheater flue collapsed on a preserved loco in the U.K. - fortunately no-one was seriously injured but a lot of boiling water and fire was blown back onto the footplate.
Unfortunately if one flue is 'thin' at the end the rest won't be far behind so the only real solution is to remove and inspect them. If the 'body' of the flue is sound it is possible to weld on new "bottle-ends" but that depends on your boiler inspector and Danish regulations. Depending on the age/condition of the smoketubes it is probably worth replacing them as well.
Cheers,
Ray.

Update.

I don't think our superheater flues are screwed into the tubeplate.

I was not there, but the flues were re-rolled and beaded in the mid-week. The engine was in service Friday-Saturday-Sunday and I was fireman on Friday for the afternoon. I did not see any evidence of leaks in flues or tubes that day, but I did notice a leaking staybolt on the outside lower engineer's side. The engine steamed very well and held pressure like a thermos even when the fire was nearly gone at the end of the day.

Sorry I never got around to posting the photo of what the tube looked like, its been a busy week. This is what we were looking at when we came back to the locomotive on Tuesday. The problem was sealed up by the end of the day, and we did not have issues with it after three days of mainline running. So, by the way things currently are, the problem has been solved and we are happy to have worked the problem out!

also, to answer another poster's question, the tubes are most definitely not screwed in. I have never heard of that practice and can say that all Danish locomotives with copper fireboxes, both welded and riveted, do not have screwed in flues

Pleased it worked out for you and there was a lot of good meat left in the tube end. Is that a single? The Brits found them slippery - how is starting a train with this one?

Dave -

I see two sets of drivers in the photo; probably a 4-4-0, but I may be wrong. Anyway, not a Single for sure.


Les

Yes, an "American in Denmark". The last axle is buried under the cab and leaves no room for a seatbox.

My old monitor strikes again. A single would have been interesting.......