I have ask some of my contacts that are in the steam locomotive repair busness in the UK for details of the defects but exact information seems hard to obtain.
As for the u-shaped mud ring I know that the SAR class 4-8-4 were equipped with that style of mud ring and seemed to have proformed well.It would be interesting to see the drawings of the boiler to view the exact construction. Also in the UK the larger locomotive fireboxes are all copper except the modern Southern Railway Pacifics which had steel fireboxes with the U-shaped mud ring, A few copper fireboxs in the preservation era were replaced with steel boxes with the general opinion that it was a mistake and had poor results . Now in the UK most repair and replacements seem to be inkind or stick with what worked.

I am curious as to the source of the boiler steels used, sheets, stay material, ect.. the unspoken concern in pressure vessel circles is the iffy quality of some imported steels, especially those from a recently industrialized Asian nation. Depending upon whom you talk to, this is due from poor chemistry and control at the mill, to downright falsification of mill specs. There have been several instances of boiler tubes with very little time under steam, in both railroad and heating boiler service, that had random failures from oxygen attack, and what appears to be embrittlement.

I wouldn't immediately jump on the mud trough, as opposed to the mud ring, as an inherent design flaw; it could well have as much to do with welding procedures as anything else.

I look forward to learning more, but I don't know if its the flu I am fighting, or my basic paranoid nature, but I really, really don't trust a lot of what passes for metallurgy these days.

I believe the U-shaped foundation rings have been successfully used on many engines. The Bullied Pacifics had them for instance. The arrangement definitely had some advantages, but I'm not sure how well they compared overall to conventional mud rings.

In the absence of any real facts, it is way too easy to blame what is unfamiliar in our practice just because we aren't familiar with it. We stopped developing new boiler techniques long before European, Antipodean and Asian engineers gave up on it. I'm more concerned about a political whitewash that will prevent the facts from being analyzed openly for the education of us all, since we are all reaching the point of unsupportable returns with piecemeal repair of some of our original boilers and replication will be very much in demand.

dave

A couple of years ago we purchased som "e" clip rail fasteners from a reputable supplier here in the U.S. They were imported from India, but they met the specs and hard the right paperwork. These roughly pretzel shaped pieces are under quite a lot of stress when they're installed.

As they were being installed, the crews found that they broke quite easily. Not only that, but only a few days after installation, before any train traffic was running on the new track, they started to break at random. (Which was pretty scary, as large heavy chunks of the clip would fly through the air when they did...)

The Indian manufacturer assured us they met spec, and even offered to fly a representative to India so we could see the plant first hand. (You can tell at a glance if molten steel meets spec, right?)

We ended up removing them all and replacing with domestic, at a not insignificant cost to the supplier. Again, what's important here is that I had all of the proper paperwork on these supposedly spec components.

.

That's known as the Xerox certification. As in, find someone who has a valid certification, and Xerox it.

That's the same reason I just passed on a pair of Chicom safety shoes. Who knows if they really meet spec., or if they just forged the certificate. I'm not about to risk my toes to find out.

This version makes sense. It's probably forged and fits up to the side sheets differently than the Tornado's. The German piece is machined and looks butt welded to the side sheets from what I can tell in the photos.
This would be easier to wash the boiler than the traditional mud ring and as you say, cut down on places for grooving.

The Germans apparently used the U-shaped butt-welded foundation rings on welded locomotive boilers for a long time. There may be a problem with the execution or the materials used on Tornado, but the concept appears to be well-proven.

Hi All

The following was taken from A1 web site on their news page.


http://a1steam.com/index.php?option=com ... Itemid=123



“Tornado's boiler - an update
Wednesday, 12 January 2011 16:24
The A1 Steam Locomotive Trust today announced that Tornado’s boiler would be returning to its manufacturer, DB Meiningen, in Germany, following the discovery that more extensive repairs to Tornado’s firebox were needed than originally anticipated when the winter maintenance was planned. Although the full extent of the repairs has yet to be agreed with DB Meiningen, they will include the replacement of several hundred fixed stays and a number of flexible stays as well as repairs to cracks in the two back and two front corners of the foundation ring. Only a very small number of weeping stays were identified out of the more that 2,000 in the firebox and therefore the overwhelming majority of the firebox stay replacements are precautionary to prevent further unplanned work during periods in traffic. The boiler will be lifted from Tornado’s frames later this week at the NRM, York, and sent by road and ferry to Germany where a full assessment of the required work will be made and a rectification plan agreed with Trust engineers. The Trust decided to return the boiler to its manufacturers due to their intimate knowledge of the construction of this type of firebox and the resources they have available to rapidly effect the agreed repairs. The firebox has already been inspected by the Trust’s boiler inspector and representatives from its VAB, insurance company and operators.

Mark Allatt, chairman, The A1 Steam Locomotive Trust, commented:

"Although these problems with Tornado’s firebox are part of learning about the locomotive in today’s operational environment, they are a source of great disappointment to all of Tornado's supporters and customers and our customers' passengers. As a part of our commitment to get Tornado back on the main line as soon as possible the Trust decided that the most appropriate course of action was to return the boiler to its manufacturers. We are working as hard as we can to bring Tornado back to full health and onto the main line at the end of April."

Progress with the work can be viewed here and here and here!

Tornado's boiler is now en-route to DB Meiningen, Germany. Upon arrival early next week it will be inspected and a plan of repair work to the firebox agreed with A1SLT engineers.

The operation to remove the boiler can be seen here”

I wish the A1 project well in there efforts to return the Tornado to steam and I wish to thank them for openly reporting on the current status of the locomotive. While it will raise a lot of discussion it also will hopefully educate people on locomotive construction. There are links embedded in the original news release that if interested I suggest you visit the A1 web site.

Respectfully,

Robby Peartree

Do I remember correctly that the mud ring on the Bulleid Pacifics was forged? I wonder if this is true of the A1 mud ring.

On our last trip to York, we took care to fondle the mud ring of an operational Bulleid Pacific when no one was looking.

LOL!

Just looked through my copy of O.V.S. Bulleid's biography and the boilers on the Bulleid Pacifics definitely had the U-shaped mud ring. No indication whether it was forged or not. There is a good photograph in the book of the completed inner firebox with U-shaped mudring attached; someone with a better eye than I have might be able to tell.

I also checked "the Red Devil and Other Tales from the Age of Steam". It shows at least one L. D. Porta designed boiler with the U shaped mud ring and I'm sure I've seen others. My guess is Porta was pretty confident of its proven reliability if he proposed it.

Let's be clear on a view things. The Tornado's TROSS style of mudring is not a U shaped, pressed plate as shown in Mr. Austin's photos. It is a U shaped channel milled out of steel bar stock approx. 6" square. And yes, Mr. Porta found good performance from this design. I like Kelly's post of the drawings of the 1937 D&H all welded boiler mudring showing this design but using a milled shelf that the sidesheets set on. The sidesheets were only seal welded to the mudring with threaded and driven staybolts going through the lip of the mudring and the sidesheets. Also, Dave's admonition that "in the absence of any real facts, it is way too easy to blame what is unfamiliar in our practice just because we aren't familiar with it." Or to quote Mr. Porta, "what I don't understand is necessarily wrong!" DB Meiningen has built maybe 35 locomotive boilers in the past 25 years with high quality and great success of performance, economy and longevity of service. They have built all welded boilers with welded staybolts in steel fireboxes. I doubt if any steel plate quality or welding/workmanship problems will be found. It's great that the A-1 website has been so forthcoming with the details thus far. Let's see what they find and fix in Meiningen. How much do you think the following may have caused these problems? 1. Fire up practices that greatly stress the boiler, staybolts and firebox. 2. Over the road firing practices - problems - and resolutions. 3. Thermal cycles of the boiler. 4. Does the standard British plate frames design properly and adequately support the boiler? Certainly these problems will be fixed and we will see many years of fine running from TORNADO.

At some point they should dig out the Kepner-Tregoe playbook and do a root cause analysis.