6202 Turbomotive/46202 Princess Anne

I suspect that a (mechanical) CVT able to handle 2000-odd horsepower would be tricky to design. Much easier is either electric or hydraulic transmission.

 

A mate had a DAF back in the 70s, and I drove it on several occasions. It felt odd as the engine revs held steady even though the car was accelerating. As described by @LMS2968, the belt drive system relies on the pulley being formed from two opposing cones. The belt is trapped between the faces of the cones. Because the width of the belt is fixed, increasing the distance between the cones reduces the effective diameter of the pulley, and vice versa, to vary the gearing.

It worked well enough, but I doubt the system would have been robust enough to drive a steam locomotive. More modern toroidal systems probably would be. Check the following links:

https://auto.howstuffworks.com/cvt3.htm

http://www.torotrak.com/products-partners/products/torotraktransmissions/

In the early 90s the Williams Formula 1 team tested a car with CVT which was immediately (from memory) 5 seconds per lap faster than the standard car. In F1 this is a lifetime! The response of the FIA was to promptly ban it. That was a pity, because we would probably now be driving around in more efficient road cars with CVT, rather than the silly flappy paddle systems seen on some high end models. I'm not sure which system Williams used.

By the way, to my recollection the MG F used variable valve timing, @RalphW are you thinking of this? I don't remember it having CVT although I may be wrong.

Of course, all this is hypothetical because a new improved Turbomotive will never be built, but it's fun to discuss how a project that was so nearly a success, could have been transformed using modern technology not available back then.

Dave

 

If Turbine Locos had entered series production surely the costs may well have come down significantly - 800 odd Turbine Black 5's would have had a much lower unit cost & fewer servicing issues than a 'one off'

 

Hydraulic perhaps, but surely the weight penalty involved in steam-electric transmission would be as significant as between diesel hydraulic and diesel-electric.

Interesting notion, but I wonder ..... does that neccessarily mean these costs would work out lower than for a bog standard reciprocating Black 5?

 

What I think is interesting is that the basic Stephensonian concept was basically fixed by 1830. Variable cut off valve gear and superheating improved the breed, but pretty much any other successful advance in the next 130 years was only in the nature of refining and enlarging the basic concept, not fundamentally changing it. It took two separate radical changes of concept (either - electric traction, entirely separating power generation and power use or - moving from external to internal combustion engines) to make a distinct break from what Stephenson would have recognised. Pretty much anything else radical that was tried between 1830 and 1960 fits somewhere on a continuum between "outright failure" and "not sufficient improvement to be worth the hassle".

Tom

 

Which was always my gripe with 5AT project as a steam loco for the 21st Century: whatever way you looked at it, it was still basically Rocket grown up.

 

That strikes me as a most appropriate thing to have in the 21st century. (But this is serious thread drift.)

 

As said, basically all steam locos are just enlarged Rockets. If you put an engineman who worked on the Liverpool & Manchester in a time machine and then gave him a 9F, after a bit of familiarisation, he would be able to fire/drive it.

6202 was the most successful attempt to try a different approach, but as Tom said, it wasn't enough of an improvement to be worth bothering with any further. The thing is though, at the time when these experiments were being carried out, diesel traction was developing so no further work was done on new steam ideas, the BR standards, and late LMS Ivatt locos, only development was in the areas of servicing. They were a bit easier to maintain, but the performance was no better.

With the Leader, I'm not sure of how much "outside the box" this was. Apart from the fact that it was much too big, complicated and heavy for the work it was intended for, the main thing which marked it out as different were the use of sleeve valves, if it had used normal piston valves it probably would have been better.

 

What alternative would you suggest?

 

Tornado? The P2? The Unknown Warrior? Mainline steam is ultimately a heritage product So even if the motive power is built in the 21st century, it has to look like it wasn’t. To my eyes at least, the 5AT was simply neither one thing nor the other: not a highly efficient way to deliver mass transport, but not an evocation of a golden age of rail travel either.

Tom

 

As Tom says. Also it wouldn't be sufficiently efficient, and not just in coal or oil consumption as the modern day's operators require, but also in crewing requirements, forward visibility, two-way operation, adhesion, etc., etc., but would lack the olde worlde charm to appeal to the masses.

 

I used to have one of those.

 

It was neither one thing or the other, it wasn’t a heritage loco, and, in my opinion, not particularly attractive, sort of a bit German looking with a huge bogie tender, like something off the Pennsylvania or New York Central. As it has no British heritage, it didn’t appeal to steam fans, but as it was still steam, modern traction enthusiasts wouldn’t be interested it either

 

The 5AT did somewhat uncomfortably attempt to staddle two opposing purposes and ultimately finished up failing to fulfill either. A lot of the work done may well prove useful, even applied to conventional locos, but aspects like Walschaerts valve gear, seemingly specified on appearance grounds alone, were indicative of the somewhat bipolar nature of that flawed yet fascinating project.

The point has been well made previously that, from a commercial viewpoint, steam - certainly the Stephensonian model - is a dead duck. That said, there's plently which could be done retrospectively (though never to be inflicted on sole survivors!) to ensure future generations can enjoy the sight of huge colourful chunks of hot metal clickety-clacking past lineside posts with strips of red and yellow metal describing arcs in the air.

Righty-ho ..... back to developing a Porta/Riddles inspired 0MT (wonder what you could call it?) for minimalist heritage operations and Follow-the-Leader bogie mounted turbomotive*, coming to a railway near you, no time soon!!**

* If only to defy anyone to define a turbo job as a "big chuffer'!

** Not really ..... actually, I'm off to the pub for a Xmas drink before a friend of mine bu**ers off to Tenerife until the new year.

 

Sentinel locos were probably the greatest diversion from the Stephenson locomotive. A vertical water tube boiler; a separate poppet valve engine unit, very similar to a car engine, and a non-rod drive to the wheels. I often wonder how much more it could have been refined in terms of a larger loco. Unfortunately the larger versions don't seem to have been further developed. Such an example given here: http://www.aqpl43.dsl.pipex.com/MUSEUM/LOCOLOCO/colombia/colombia.htm

Incidentally, I always understood that the Stephenson locomotive concept we know today was first seen in the Northumbrian and not the earlier Rocket.

 

It's why in my post I said 1830, Steve, rather than 1829!

Tom

 

Others mentioned the Rocket thingy, though!

 

What was the significant change from Rocket that then remained with most subsequent steam locos?

 

If you compare the boilers of "Rocket" and "Northumbrian", Rocket's boiler is essentially a barrel (with multiple tubes) but the firebox and smokebox are something in the nature of add-ons, not fully integrated into the whole. Northumbrian had a multi-tubular boiler in which the firebox was an integral part of the boiler, and the smokebox extended to the whole diameter of the barrel, as became the standard practice.

Tom