Sir William A. Stanier, FRS

I am sure there are some people on here who still think it should be Brunswick green, even with the bathtub...
Mind you, I would pretty much paint anything that can boil water in Crimson Lake, so who am I to judge?

 

It's a 2-sided argument for me...
Yes, it would be a very expensive millstone for someone / a group to maintain. It would also not be unique, so may not generate the support of other New Build ventures.

BUT - It would be completely new, with zero-hours wear and tear on all components - And should last a lot further into the future than the currently preserved examples as a working machine (going on the estimate of a 110-year lifespan before major metal fatigue sets in).
It would also be nice to see a new one built using the benefit of hindsight - Larger flue tubes as per the Britannia boiler, fewer small tubes, and an attempt to find a better lagging solution to the superheater elements at the smokebox end, to keep the superheat temperature up to what the expectations of the Friends of the NRM was with 46229, and which was never fully achieved.
46229 achieved some magnificent outputs, but using a new build to further refine the non-visible details would be very interesting - As far as I know from what I've read over the years, the Ivatt Pacifics' boiler internals were more or less the same as the Stanier ones.

Richard.

 

I'm not sure any significant improvements would be necessary, other than those made to it when in service (I think the reversing clutch and some bearings were modified and it certainly needed the higher superheat boiler). Its success was due to its relative simplicity. It would of course cost more to build than a conventional loco but then the P2 isn't the cheapest Class 8P to build, perhaps someone might justify the extra cost for such a unique loco.

The big problem with 6202 would be that it would ONLY really be suitable for main line workings;- being unable to haul significant loads in reverse wouldn't really be much use on, say, the NYMR!

 

Ultimately ALL of the preserved fleet is either going to be life expired or rebuilt so much that little to none of the original survives. Assuming working steam has a future beyond the next 20 or so years there is going to be a place and a need for new builds of all types to replace the current working fleet. I sincerely hope that 40 years hence there is still the opportunity to see a Duchess working flat out on the mainline and I think there is more chance of this happening with a relatively new loco than any of the 1938 built examples - even if their owners sanction the amount of mechanical renewal that will be necessary in the period between now and then to keep them mainline availavble.

 

When it comes to extinct 7-8p's there isn't much else left... Great Bear, A Raven Pacific, Thompsons Cut and Shuts, LNER 10000, A Fowler Scot ?
then your into what ifs; Hawksworth Pacific, Gresley and Staniers 4-6-4 /4-8-2 's Bullied and BR Standard 2-8-2's ?

 

Totally agree how much of TR No1 and 2 is absolute genuine Lowca works 1862?

 

Yes, eventually locos are going to be life expired and we may be nearly 50 years after the end of steam but, when you look at the mileage that most locos have done in that time, the cumulative wear and tear isn't that significant. Most post war locomotives would be considered as having many more useful miles left in them before they are too worn out to warrant overhauling.

 

Don't confuse the situation in BR days to today. In those days, the big Railway was running a fleet of locos and it made economic sense to replace worn components to get a very valuable piece of kit - a very expensive locomotive - back into traffic and earning money as soon as possible. Even so, many parts stayed with a loco for a a very long time; I can state that most of the valve gear on the Stanier Crab are stamped 13268, meaning they've been with the loco since built in January 1934. The assumption seems to be that the displaced parts were scrapped and the replacements were new: not so. To take a major component as an example, many Black Fives had their frames replaced during their lives. In fact, Crewe (and possibly other works) held a spare set of frames to replace the badly cracked ones of an engine under overhaul. The new ones were fitted and the loco returned to traffic, but the displaced ones were then fully repaired and placed in store, and would be fitted to the next loco with poor frames, and so it went on. Many locos might have completed their lives with no original parts, but many of those parts would still be in use - on a variety of different locos - and have a life span at least as long as the engine they were originally fitted to.

Today, the situation is different as there isn't a large stock of parts to replace worn ones. These worn parts will be removed and overhauled as previously, but today will be fitted back on the same engine from which they were removed. There is a lot of life left in these locos yet; writing their obituaries at this time is more than a little premature.

 

Components are going to be life expired and replaced for sure, but I'm not sure about locomotives. Presumably Locomotives were scrapped and replaced for two reasons: because they were not cost effective to repair and because they were obsolete: usually both. Very few locomotives were replaced with ones of intrinsically the same design: on the GWR/WR I can only think of a handful of early conversions to the Castle class that were replaced by more Castles.

Obsolescence is no longer a factor, and overhaul costs are very very different now there are no longer the big works. So I'm not sure there's any reason why grandfather's axe shouldn't have a few more heads and handles...

 

Would improvements be necessary? No, not if you were building a replica. On the other hand, if you wanted to use modern technology and design techniques to get the best out of a concept (as for 2007), then that changes everything.

For those not familiar with continuously or infinitely variable transmissions, the idea is that the power source (be it internal combustion, turbine or whatever) runs at its optimal rpm at all times, and the gearbox changes its ratio according to the speed of the vehicle. To put this into perspective, about 15 years ago the Williams F1 team developed a CVT gearbox for their car. When they tested it at Silverstone it was instantly 3 seconds a lap faster. In F1 that is a colossal improvement, so the FIA (the governing body) immediately banned it.

The two major problems of 6202 was that the turbine was almost never operating at its optimal rpm, and being fixed drive it needed a second (smaller) turbine to enable it to move in reverse, but with no significant load hauling capacity as LB points out. Both these problems could potentially be solved by using CVT.

Could it ever be achieved? Who knows, anything is possible if money is available. Maybe Siemens and/or Torotrak would come on board as sponsors for the publicity or as a technology demonstrator? That would help, but it would still cost a a lot of money, but.....

What a project it would be! Far more exciting than a replica 6256. I think 6202 covered about 400,000 miles, so the basic concept was sound. What is needed is an LMS equivalent of David Elliott. If it ever got off the ground I would definitely be a contributor.

Dave

 

I believe that 6202 was already slightly more powerful than its sisters with pistons, so a version with CVT should be more powerful than anything that has ever run in Britain. That leads two ways. One possibility is a steam loco better able to fit in on the modern railway, but especially if allowed to run up to, say, 90 mph, which should be permissible for a design with no reciprocating parts. The other is a considerably smaller loco with similarly high power-to-weight ratio, perhaps Class 5 size but Class 7 power.

But all of that is serious thread drift from 46256.

 

But what would be the point? Surely a replica of 6202 should be just that. A radically new efficient form of traction ultimately leads to the diesel or electric route.

As regards a new build 6256, all I can wonder is when is a new build Castle going to get a Facebook page.

 

I'm just waiting for when the GWS announce a radical plan to transform the mortal remains of a Castle into ... a Castle ...

Tom

 

Don't give them ideas!

 

Not sure that a CVT transmission would be the best idea. If you are doing that, you have to match engine power to continuous boiler power. One of the advantages of a steam loco is that it has a huge reservoir of energy in the boiler which allows short term power outputs well in excess of the steady state output.

 

The use of CVT would not of itself make the loco more powerful, but what it would do is to make the maximum power available over the full operating speed range, from standstill upwards. This, though, should dramatically improve performance.

I think the original had a 1,800kw turbine, so you might want to increase that to, say, 2,000kw to compensate for additional losses in the CVT gearbox.

But I have no idea if suitable turbines or transmissions are available off the shelf, you would not want to be developing bespoke components.

 

A while ago, while reading about 6202 and its shortcomings, it occurred to me that a CVT could have transformed the loco if such a thing had been available back then. So when the idea of a new build was suggested on this thread, I took the opportunity to put this forward.

True, you could build an exact replica, but you would then need two turbines and would also have to accept that it would be useless on heritage lines as pointed out earlier in the thread.

Although costly, there would also be savings as compared to 6256 - you would not need patterns and castings for four cylinders or four sets of valve gear.

Personally, I doubt that either project will ever go ahead, 6256 or 6202 (original or improved), but it's fun to discuss these things.

Dave