Tornado

A very kind thougth NeilL!

Also like the A1 Trust states "the best way to support Tornado in the long term is to sign up as a monthly convenantor"

 

And a car sticker... sign me up?!

James


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Problems with pawl and ratchet drives to lubricators are not unknown as I understand it. Alternatives have been tried but have failed to function well at certain speeds. So it was back to square one, with tweaks and improvements you might say.

The withdrawal of 60163 for the remainder of the current season means that those working on the engine are not under the pressure to meet an imminent deadline. Which can only be viewed as a good thing.

The frames of the A1 appear to "work" - this is a divided drive 3 cylinder engine which is not seen as the best way of arranging the drive. You can build a high power output 3 cylinder machine with divided drive but the frames need careful attention, I know of one very good example. Compared with what has been achieved the majority of UK built divided drive machines are not particularly high power output. The nature of the system balancing is a factor but if the centre line of the inside cylinder is moving laterally either side of the frame centre line when the locomotive is working and the degree of displacement is proportional to both how hard and how fast the engine is working then this is less than ideal. Now, what could cause cracks in the running boards? No prizes.

The building of the next A1 has been and remains a remarkable achievement. But if you recall a very capable locomotive engineer wanted to steer the project away from divided drive.and back towards unified. This would, in all probability, not have got an engine built. And this same engineer wanted to push the overall design beyond what the loading gauge could perhaps handle and most certainly beyond what the acceptance bodies could cope with. Think Super A3 as a compromise (though you wouldn't have got this built either). Unified drive engines in preservation tend to have a rather good reputation, conjugated gear or Walcheart gear, run them at 60mph, 75mph or substantially higher and strange to say they tend not to suffer catastrophic events.

 

I have said it before (and I'm sure W Williams disagrees with me) but steam locos are not built to thous, they are built to work and if you start to reduce tolerances you start to produce problems. They are not rigid machines on a solid foundation. Those who maintained and operated them in days of yore knew this.

 

Sorry, thought you meant some newer information.

 

Seems a bit of a cheek to me to launch an appeal asking for funds to cover lost revenue etc due to catastrophic failure whilst pushing the loco to its limits..... On the other hand you have to admire the fundraising machine that is the A1 trust on turning a negative event into a positive fundraising opportunity...

 

Limits and fits data has been arrived at through many many decades of operating steam on a day to day basis, the information isn't difficult to come by.

 

Your posting has reminded me of this paper from the Swindon Eng. Soc., although it's some time since I last read it!

http://kesr-mic.org.uk/resources/The+Steam+Locomotive-A+Machine+of+Precision.pdf


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We are addressing a different issue here. Elsewhere in the world rigid frame structures were the rule and engineering solutions addressed the peculiar nature of the floating crankshaft model, lateral axle movement etc. etc. Are you saying that a cast steel bed is not a solid foundation? Because that is what it was built as. So what are you really trying to say? If you don't like more advanced designs, particularly those built to run high mileage with low maintenance then just say so. If you prefer a multitude of parts, bolted and riveted together rather than something produced in a single piece, that is your choice. Don't think that any North American railroad would agree with you. They moved to build their engines on rigid foundations, and the French liked their 141R locomotives too, and the SAR their Class 25 and so on and so on and so on. Common theme here. Don't like it? Feel free.

The A1 design has suffered a valve gear failure which is most regrettable. An engineer far better qualified than anyone who posts on this forum advised against divided drive but the deed is done and so the best has to be made of it. And we should be grateful at a number of levels that it has. If frame movement is occurring to the point where the running plates crack (and you can look for the cover plates) is this movement sufficient to impact on the long term integrity of the valve gear?

 

In many cases restored locos have a huge amount of new material and components in them so I'm not at all certain that your argument holds water.

 

Who did warn against the layout as buillt?
The german three cylinder pacifics in highspeed service were no end of trouble and was same layout.

In german
ISBN 978-3-88255-216-4

Someone from Meinningen argues that 120 degree coupling rod angle and divided drive was not very good on locomotives asked to do 1000 km a day on the far side of 100 km/hour.

 

All this talk about the drive layout being flawed seems wide of the mark. As I understand, the last five roller bearing A1s ran an average of 118,000 miles between general overhauls. They had the lowest per mile operating cost of any pacific owned by BR. Only premature withdrawal well before the end of their useful economic life stopped the originals achieving lifetime mileages of 1.5 - 2 million miles that might otherwise have been expected.

So whatever the supposed flaws of the design, it doesn't seem too have hindered the originals, and no reason why it should hinder "Tornado". Reference to "an engineer far better qualified than anyone who posts on this forum" is I assume in relation to L.D. Porta. His proposal was to build something quite different from an A1. Possibly in his position I might have done similar - who wouldn't want to see their own original design built and running? - but it seems in retrospect a misguided proposal whatever its technical merits,. Instead, the A1 trust were, in my opinion, entirely right to build a new example of what was a historically proven, reliable design but with the solid commercial appeal of being a heritage design; rather than embark on a risky development of something that would have had to be designed and certified from scratch without the same heritage appeal to those likely to fund it.

Tom

 

I'm not saying anything that you've said above. Cast beds will undoubtedly lead to increased rigidity but show me an example that ran in the UK in any number? Even with cast beds, the locomotive has suspension so their is relative movement of parts between sprung and unsprung.
In all this, we are talking about essentially Victorian engineering, updated with mid 20th century knowledge and know how, not a hypothetical new build that has all the knowledge of 21st century engineers. If you want to go ahead with such, that is fine, go ahead and do so, but it won't be an A1, P2 or any other loco that we know of and what we are essentially talking about.

 

And locomotives that have had major rebuilds during their restoration - e.g. Galatea with new driving wheels and much else or 71000 with new cylinders etc. - will have had a myriad of components sourced from different locations.

 

At a different level it's easy to forget that Tornado has been operating successfully for 10 years until last April, including successful trials at 100mph+.

 

I’d suggest the opposite is if anything more likely, as there are not the unknown quantities of how BR sourced parts to consider.


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No, it was not being pushed to its limits. A1s ran at 90 mph and more in BR days, Tornado was designed and built with the intention of running at 90 mph whenever permitted, and it had a successful test run reaching 100 mph while covered in instrumentation to confirm that all was well. The failure has been investigated very thoroughly and the several contributory causes identified, speed not being one of them. Considering the strong rationale for higher speed, to facilitate pathing, I personally wonder why the Trust is being so cautious and deferring another go for so long, but it's their decision, in consultation with DBC, NR, etc.

 

And on the other hand, those of us who rebuilt a Barry wreck had no idea of the provenance of such parts as were still left on the loco or subsequently obtained second hand. I’d argue that we knew more regarding the quality of the con rods we had made new than the coupling rods we obtained second hand.