Tornado

Fair points. I remain unconvinced that residual stress plays no part in the story, though. There must be some methodology for handling that issue.

Cyclic stresses shouldnt crack the welds prematurely. If the welds are not meeting their expected service life, then its probably because there are other factors at play, either overloading, or residual stresses remain in the weld from manufacture. Or the wrong materials were used in the weld.

 

See @W.Williams post with which I concur.

 

I would think that the difference is in the water space dimension, so unseen.

 

From memory the fixed stays are fillet welded outside in over-sized holes to allow the stays to flex laterally unhindered. They are also drilled out which provides a tell-tale for fracture inside the firebox.

 

Weren't there similar problems with the boiler that Meiningen built for the Australian Pacifc 3801?

 

Worse - after sending it back to Germany for rectification they eventually decided to overhaul the original boiler instead. The German one is stored.

 

I think I recall that the owners of Australia Pacific 3801 took legal action against DB Meinegen.

 

3801 report to supporters :-


3801 Overhaul and New Boiler

10 August, 2011

By now, many members of the community will have heard that there are problems with 3801’s new boiler.

This new all-welded boiler, delivered to RailCorp’s Chullora Workshops in late October 2010, was designed and manufactured by Dampflokwerk Meiningen – a division of Deutsche Bahn (DB) in Germany – under a contract managed by RailCorp. Until now, the sensitive nature of the negotiations between RailCorp and DB, has rendered it impossible, for any sort of detailed statement on the condition of the boiler to be made.

For the RTM staff and volunteers of the overhaul team, the period from November 2010 up until the last few weeks, has been one of uncertainty – a situation made all the more difficult in the absence of an agreement between RailCorp and DB – where public comment about the boiler would have been imprudent. However, by the time of this update, agreement should have been reached and the first physical steps taken on the path to rectifying the boiler.

Throughout the mechanical overhaul phase of the project, the team at Chullora has been working to get the locomotive chassis (frame, wheels, spring gear, etc.) repaired and re-assembled to coincide with the boiler’s delivery and largely, this milestone was achieved. So, it was a very great disappointment for the team to discover that there are a number of problems with the boiler, some very serious, which will create a significant delay in the completion of 3801’s overhaul and return to service.

An initial inspection raised concerns about the quality of welding on the firebox rigid stays and the flues, tubes and arch-tubes inside the firebox. This matter was referred back to the manufacturer for comment, who immediately agreed to rectify any defects to RailCorp’s satisfaction, during an expected visit to commission the boiler, planned at that time, to take place during the last months of 2010. In the meantime, as part of preparations to reassemble the locomotive, the boiler was lifted and test-fitted to the engine frame in late November 2010. At first, this operation appeared to go smoothly, however attempts to fine-tune the positioning of the boiler the following day, demonstrated that the front tubeplate would not interface correctly with the smokebox shell, even though the firebox could be positioned perfectly. Some simple measurements were conducted, indicating that the front tubeplate was not perpendicular to the horizontal axis of the boiler barrel. Emotions ran pretty high and low that day.

Although everyone associated with the project had different views on what might be expected with regard to the differences between riveted and welded construction, no-one was prepared for the possibility that the boiler would simply not fit correctly into the frame. The expectation was that the boiler should have been a duplicate (albeit of welded construction) of the original one and only needed to be positioned in the engine frame, before the final re-assembly of the locomotive would commence. A visual inspection of the barrel raised further questions so, at the suggestion of the Boiler Inspector, a detailed survey of the boiler was undertaken by NSWRTM staff, with assistance from an independent, highly-qualified boiler expert. This survey was carried out through December 2010 and confirmed the front tubeplate problem, but also identified the barrel itself suffered from localised out-of-roundness and peaking of the longitudinal welded seams. It also confirmed that the weld-quality on rigid stays and boiler tubes, etc., was an extensive problem.

DB-Meiningen was issued a copy of the survey report and requested to comment. From mid-January through to early March 2011, RailCorp, aided by NSWRTM’s Boiler Inspector and independent boiler expert, undertook an intensive series of technical discussions and correspondence with DB in an attempt to resolve the boiler problems. Ultimately, DB was unable to prove that the boiler, with its faults, satisfied NSW OH&S; Regulations. As a result, RailCorp served DB a notice of non-compliance and requested DB to advise how it proposed to rectify the defects in the boiler. It was agreed in mid-March that DB-Meiningen personnel should visit Australia to witness first-hand the boiler’s problems, and this visit took place in late April 2011.

Jürgen Eichhorn (Works Manager, DB-Meiningen), Achim Decker (Chief Design Engineer, DB-Meiningen) and Uwe Sprengholz (representing TÜV Thüringen – the German certifying authority) visited Sydney for three days in April 2011. The visit involved an all-day detailed inspection of the boiler at Chullora, followed by a conference with RailCorp, RailCorp’s Engineer & Technical Advisor and, the NSWRTM team. This face-to-face meeting culminated in a ‘heads of agreement’ committing RailCorp and DB to a resolution process.

This detailed process has been followed through late-April to mid-July and has resulted in an agreement between RailCorp and DB to ship the boiler back to Meiningen, Germany, for rectification of the defects identified during the conference in Sydney. The final details of this scope of works are currently being finalised between the parties, but will largely consist of:

• Replacement of the defective boiler barrel with one of true conical form.

• Re-attachment of the front tubeplate accurately to allow correct interface of the
  boiler to the smokebox.

• Rectification of welding to firebox rigid wall stays.

• Boiler flues and tubes to be expanded into firebox tube plate before seal-welding.

DB has indicated approximately a twenty-week programme of works, exclusive of return-shipping between Australia and Germany. The boiler is expected to leave Chullora in August 2011 and be returned mid-year 2012. The independent boiler expert involved in the assessment of the boiler problems will also represent RailCorp’s interests in Meiningen, at critical stages of the rectification.

Although during the boiler’s design phase, the method of design for firebox rigid stays was agreed upon between RailCorp and DB, a subsequent analysis has revealed the stays to be non-compliant with Australian Standards and thus non-compliant with the requirements of the NSW OH&S; Regulation. DB’s design method resulted in stays which are smaller in diameter than the minimum allowable by Australian Standards. As a pre-requisite to the issuance of a boiler certificate by the Boiler Inspector, RailCorp will execute a program of progressive, in-service stay replacement, with the aim of replacing all rigid stays within approximately eighteen months.

Now, with some certainty that the boiler is going back to Germany for repair, RailCorp’s Office of Rail Heritage has signalled its support and commitment to the overhaul team at Chullora and has made extra provision to fund the continuation of the project during the period the boiler is away. In some ways, the team sees this as a blessing because it allows some worthwhile jobs to be tackled that were never contained in 3801’s original scope of works. For example, it had never been envisaged that time would be available to undertake major repairs to 3801’s running boards, streamlined casing and boiler clothing – so with ORH’s support, the delay gives the team an opportunity to make 3801 just that little bit better.

Naturally, the lack of any credible information from official sources has led to all sorts of rumour and innuendo about the overhaul of 3801, the boiler and the future of the locomotive. Certainly for all involved, the investigation and negotiations with DB have been intensive and on occasions difficult, but at no time has there been any suggestion that the project would be cancelled; indeed the effort invested by everyone during the last eight months or so, has all been aimed at getting 3801 completed and back into Heritage Express™ service.

 

"Naturally, the lack of any credible information from official sources has led to all sorts of rumour and innuendo about the overhaul of 3801, the boiler and the future of the locomotive"
<fx:/Waves at A1SLT>
I'm hoping they are in the same sort of negotiation, and that's why nothing is coming out. But I doubt it...

 

Thanks for putting this up, it refreshed my memory.

 

I am sure you’re right. Given the problems with 3801 boiler I have long wondered if the shape of the A1 boiler is quite correct. It wouldn’t take much misalignment of shape between inner and outer to start popping stays, and I with the original inner design being for copper, was the difference in the way steel behaves sufficiently considered? Happy to be shot down, but curious.

Water circulation has been a discussion many times, so presumably there is it has been local hotspots within the boiler? How severe are those? Again you could build up significant stresses this way.

Apologies if al this has been said before, I haven’t read all the pages.

 

You certainly can’t stay a welded steel box in the same way as a riveted copper one but that ought to have come out in the design process. The problem with the original boiler is that steel isn’t as flexible as copper and the narrow water spaces insisted on didn’t help with this. Having tell-tales drilled is probably another factor as it does away with the ignorance is bliss approach. You soon know when a stay is cracking, something that needs the skilled boiler smith to detect with his faithful hammer, otherwise.

 

OMHO, the decision to build the boiler with welded stays and not to increase the water jacket, was a mistake, threaded stays work just fine with a bulleid boiler, and the trust should have looked at how they are stayed, the size of the water space between the inner and outer fireboxes, the staying arrangements, when drawing up the dimensions for their boiler, but instead, it looks like they just copied the LNER design, without allowing for the different way steel boxes react from copper, , Sometimes, you can be a brilliant designer, but be narrow minded, and if convinced your right, ignore what's already being used around you,
So where does that leave Tornado, I think the whole business is on a tipping point, if the top brass press on, and try to put Tornado on the mainline, and the boiler is as fragile as some claim, it fails, or is shown to not be in a fit state to be on the mainline, it could very well be something the trust, under its present managership might not recover from, imagine Tornado failing, and being red carded on the mainline, and then subject to an involved inspection, before being allowed back out, and then further issues are found, Tornado could potentially be banned from NR metals, if its concidered to be a risk to the running of the rest of the system, how do you recover from that? That is what I think will happen, the trust will press on, ignoring the issues, the engine goes mainline, fails, because of boiler issues, fire can't be dropped etc, then gets banned from the network the trusts reputation is ruined, people stop supporting and funding, and eventually another company will buy out the trust, and put Tornado through a full overhall, and it will be like flying scotsman all over again.

 

Always the optimist Martin, eh?

 

And your reasons for optimism are?

 

NP's... Mystic Meg....

 

I don't see it happening myself, but given the post by @martin1656 above and one of the reasons for building 60163 given by the Trust, it'd be ironic if it were to find itself being plinthed...

 

I don't share Martin's views that every time there's a problem with loco X that this will lead to a catastrophic breakdown of all relationships and the loco will be sold/plinthed.
There may be difficult times ahead (for many loco groups), but I doubt that many (if any) will end up in the scenarios that Martin loves to depict.

 

The clock is ticking again….