LMS Patriot Project Updates

That's definitely not subjective, then. Were the castings MPI'd when first cast, though I would have thought that would have been routine? Definitely not good.

 

A passed NDT cert is often a requirement for payment in the terms of business within industry.

What is very positive is that all parties are collaborating to understand and move forwards.

 

Is it possible that the cracking was caused by incorrect assembly/disassembly methods, possibly in conjunction with incorrect interference fits?

 

That will depend on the nature and location of the cracking presumably...
On the assumption that all 6 failed in the same way, it has to be a process common to them all - ie you can ignore any crank axle-specific procedures
(that is a big assumption, we had one building that leaked - arguments raged whose fault and why, but all parties assumed it was a consistent fault. We took 6 panels off and all had failed in different ways...)

 

As Mike says we don't know the nature or location of the cracks and we don't know the severity of them. If they are relatively minor would they be acceptable for running at 25mph on a heritage railway even if not acceptable for the main line?
Ray.

 

But I thought the whole aim of building the 5XP 5551 Unknown warrior is that the LMS Patriot project founder members and designers and admin intended for it to be built for mainline and heritage railway usage that's why the engineers and volunteers are going through every component or bit of metal constructed like a fine tooth comb so Ricardo rail can sign the parts off in question after design and fitting deemed safe so the 5551 loco is a fit to run both mainline and heritage lines, but unfortunately this mechanical flaw from the driver wheels has cost the LMS Pat team dearly this time besides the bogie frames valve rods, and repositioned key ways all been refitted on the wheels, To discover the wheels are cracked, on the up side of things on the pat loco the wheel pans previously took a year to cast all 6 but the only prob this time is the funds could have to be raised for the boro foundry to recast them, so are members this time round going to be not put off by the chain of discoveries and dig deep again for the wheelpans to be recast under expert foundrymen and engineers so the wheelpans don't have air bubbles or airline cracking after the molten steel has been poured in the sand boxes and left to cool down very steadily, point is this time round how many more years are we to wait to see the finished 5551 5XP U.W. 2024 maybe? So yet again good luck at their next A.G.M. 31 July
Davo 56F

 

How much does 1 6.9 driver wheel cost anyway in a foundry to cast what I'm trying to work out is how much did all 6 driver wheels cost to be cast at boro foundry and before machining anyone?

 

Just seen this on the G5 Locomotive Company website. I hope they don't mind me quoting... My bold highlight.

"The two trailing wheels and tyres have been collected from the unit and shipped to SDR for final assembly. However, when they were received a problem came to light with the manufacturing of one of the wheels. Thankfully, Boro' Foundry offered to manufacture another one free of charge; many thanks to them. We dug out the original pattern, gave it a fresh coat of paint and shipped that to them."

Hopefully a work-round can be achieved with our own wheelsets. Fingers crossed.

Richard.

 

I think what is surprising me in this saga is less that there are problems - such things occur from time to time, and if making a large casting were easy, everyone would be doing it - but that the issues weren't identified at the time of casting. One wonders what the acceptance criteria were at the time?

Tom

 

I can but echo and agree with Tom. As it highlights IMO a lack of Quality Control..... These issues are as old [and older] as the railways themselves. As an example there is a railway myth that the Stephenson's sabotaged Hackworth's San Pareil when they supplied the subcontracted and defective as it turned out cylinders [which were made at short notice]. When the replica was constructed it took Crewe works 8-10 goes at making a perfect pair 150 years later.......

 

I believe that Robert Stephenson's cast six cylinders and rejected four of them, but believed the final pair were good. In practice, they made little or no difference to the Trials. The problem was the boiler, not built by RS&Co, which leaked like a sieve. John Dixon wrote, "He (Timothy Hackworth) has to feed her more more meal and malt sprouts than would fatten a pig," this being the then current way to plug minor boiler leaks. Hackworth's over enthusiastic use of the blastpipe coupled with a large diameter flue also had the effect of distributing the fire all over the landscape.

Sorry, major thread drift there!

 

Not to worry...interesting info....

 

Indeed I was using Hackworth's misfortune as an example of the pitfalls of the foundry process and it being as old as the business itself.......

 

This will definitely be a relic of the previous (first) project management team - so it fits in with the other items which have had to be re-made. The project has moved on now in terms of project management, so fingers crossed this will be the last spanner in the works, albeit a bloody big one.

Richard.

 

I'd imagine several involved with the 'Clan Project' must breathe the occasional sigh of relief that 72010 benefitted from a new, infininitely more professional approach, rather earlier in the build process than the Patriot.

Though certain the new team will recover from the many setbacks The Unknown Warrior has faced, were it a marine project, I might suggest, just to be on the safe side, they shoot an albatross to improve their luck.

More seriously, though the point has been made concerning historic attitudes to the acceptability (or otherwise) of manufacturing flaws. Of interest, are there any remaining steel casting jobs in modern industry remotely comparable to large diameter, spoked wheel centres, for use in such harsh and rapidly variable operating conditions?

 

A casual observation Im sure but the advances in moulding production methods don't seem to have made this process ( castings) any more reliable... or is it that the experience in producing them, especially large one offs, just isn't there anymore. As a 'lay' member of the Clan project i have often queried the use of Large Castings - exactly as per the original spec. when full or part fabrications might have been used. Castings have always been decided upon but its almost expected that they will not be perfect and that problems even if minor ones will be discovered either by the inspection tests or sometimes during finishing and require some corrective action. Sometimes this has been possible at the machining stage, some have just had to be redone...

 

Described as "Serious Widespread cracking" strongly suggesting 'not localised' as it would be, if it was caused as you describe above.

 

I don't know the details of the problems with the wheels but it was quite common for cast spoked wheels to crack on cooling down. In Victorian times, for this reason, it was quite common to split the rims into halves or even quarters to reduce the build up of stresses. Metal blocks or keys about 1-2" wide were then fitted to fill the gaps. Once the tyre was shrunk on, this would hold everything in place. If the job was well done, these keys would not be noticeable. When the wheel tyres on the VCT's MW1210 Sir Berkeley were replaced some years ago the contractor was quite concerned when he phoned me to say the wheels had fallen to bits when the tyres were removed. Suffice to say that I told him to put all the bits back in position and fit the new tyres. All is still well with them after twelve years and I expect this to be the case in another fifty years.

 

It is probably worth noting, I stand happy to be corrected here, that MPI inspection was not routine during 20'2/30's etc. Its also worth noting castings all have a degree of porosity and can easily be cracked compared to say a forging.

I bet there are plenty of wheels out there with cracking in them, but its not an issue because:

1. They aren't going to be run on the mainline. Well, not in anger at least.
2. The cracks are not propagating.
3. The wheels are unlikely to come off the wheels any time soon.

One thing I'm a little curious about. Some wheels were tough to get off the axles, which to me anyway, suggests the interference fit applied was incorrect.

Not saying the DWG or design was incorrect, merely that the hole-shaft values as delivered were not conforming to drawing. Big shaft in to small hole would be a very probable candidate to promote cracking.

We have to remember castings are by nature not very ductile. This makes them a bit binary. They are either good or not good. A good casting ex-foundry can become not good further down the line in the manufacturing/assembly stages. Sometimes its not even ambiguous and they go from usable to utterly un-salvageable after one operation.
As manufacturing methods go, castings are not the most forgiving.

As an aside, i am wondering if these truths are what have convinced the P2 group to opt for a more ductile, and more easily repairable, fabricated assembly.

Ach, its all by the by. Iv every faith it will be resolved and progress will crack on.

 

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crack on...I hope not again..