Tornado

I think TPWS is about £30K so not cheap and wouldn’t there be room for it? The tender front of 35028 is crammed with electronic gizmos with no room for any more. All a bit academic as I asked at the last A1 Trust roadshow about running in Europe and it was an emphatic no.

 

I am sure this was something mentioned a while ago, a decent amount to be honest.

As a PR exercise great, but in the real world, enough work exists in the UK to keep her busy.

 

Much play has been made of the CE Badge on the Meiningen boilers...was this ever/ is this now of much relevance ?

 

That depends whether the relevant regs are among those that Boris's government intends to keep or those that they intend to scrap. I believe some of the EU laws that are for the benefit of citizens, and that Boris promised to keep when campaigning for the election, were then left out of the Brexit bill.

 

It wouldn’t happen... the valve gear would fall apart again!

James

 

Rather an unfair comment on the A1 engineering team. The valve gear has never "fallen apart".

Keith

 

Possibly not an unfair comment as I’m sure all that reciprocating motion was not designed for those sort of speeds and I’m sure the A1 Trust would not be so irresponsible with other people’s money to even try it. We still don’t know the full background to the Ebor Flyer incident. All we do know is there will be no more 90mph running

 

Still unfair as it didn't "fall apart". Falling apart implies that it was poorly made or put together, which the mileage both before and after the incident proves is not the case. A part broke. Could've happened on any trip.

Keith

 

I don’t think we will ever know the real cause

 

Not really. It may not have legislative relevance, but it doesn't make it meaningless. Look at all those companies that proudly trumpet ISO9001 compliance. There's no legal requirement for them to get those certificates, but they consider there are business advantages in doing so.

 

I still think it was the middle cylinder valve seizing in its liner, possibly due to lubrication problems or due to the winter overhaul which included reboring and new rings. Despite the careful "running in" on a preserved line, that would not have generated the running temperature that the ""Ebor Flyer" running would create - especially in the middle cylinder. The previous years 100mph showed what could safely be achieved.....but the running clearances would have been at the higher end of the scale - after 8 years of running.....But this is only my opinion.

 

I'm struggling to understand the difference between 'fall apart' and 'a part broke'. If a part broke, surely it fell apart? At the end of the day, though, I'm sure that James was not being serious with his quip, just as many others are, me included.

 

I thought the Trust's explanation (roughly speaking a combination of poor lubrication, unfavourable tolerances and imperfect alignment, any one of which alone would probably have done no harm) made good sense.

Do we know that? Who has said so? The last I heard was that the failure would have taken longer to happen at a lower speed but would still have happened, and that the Trust had said no more 90 mph for the time being. The Peppercorn A1s were in most respects improved A4s, and Tornado is a slightly improved version of those, so it should be good for well over 75 mph.

 

I still get the feeling that we haven’t been told everything about the Ebor incident and what happened subsequently when the Loco was stuck at the Nene Valley with WCRC having to take over the job of moving it. No doubt, if there is anything, it will come out eventually. To run at 90mph will require a TOC willing to do it, I don’t think W.C. are authorised to and DBC haven’t said they will again.

 

Are you sure that it is improved over the A4? How many years and for how many miles have Gresley 3 cylinder locomotives run in preservation? And how many failures of the inside valve gear have occurred? And on the A4s?

We all know that speeds in excess of 90 mph have been achieved by the the preserved A4s on numerous occasions, they will have required less power output to achieve it too.

The inside valve gear fitted to the A1 is different to that fitted to the outside cylinders and reading the analysis on the Don Ashton site is interesting. You then have that single cylinder hanging out over the front of the engine, you should get Mr Elliot to talk about that one.

So apart from the roller bearings and being newer what did the A1s bring to the table? A larger grate? More horsepower can be obtained from a grate a little over 40 sq. ft. than was ever felt to be required in the U.K. So what else?

 

Well, as A4s do not have inside valve gear, the answer is bound to be none. From an engineering perspective, the reasons given by the A1 Trust are perfectly feasible and I struggle to see the need for a conspiracy theory.

Even in BR days and before, locos had been known to drop their valve gear on occasion. I recall a photo in BRILL many years ago of Stanier Pacific - generally very reliable machines - 6256 with its right hand valve gear bent and twisted, having failed spectacularly at speed on the main line.

As the Americans put it, "Sh*t happens."

 

Just when you think the horse is dead, there it goes twitching and writhing all over the place.

The Ebor incident really has been done to death further up the thread. There is no conspiracy despite how much some might want it. Seized valve and a subsequent fatigue failure in the motion.

End.

 

The A4s do have a valve gear, how could they not have? It may not be a valve gear as some might know it but it is referred to as a valve gear.

As for a conspiracy theory I agree that their is no need for one, the Trust have explained things well enough. Are you suggesting that what I previously posted supports the theory? It does not, it merely points out that the A1 does not represent the level of improvement that some believe that it does.

 

What failed in fatigue?

 

Fair enough, the Gresley engines have between the frames a 1:1 lever and a 2:1 lever, so call it a valve gear if you want. I don't have the knowledge to compare A4s with A1s from any point of view, performance on the road or mechanical; I leave that for others.

I'm unsure of the reason for your second paragraph. The bulk of my reply was a discussion with Johnb, but I've no real argument with anything in your Post 5815.