How about a V4?

Sorry, you of course are quite right, its the P2 I was refering to. In my defence Im primarily a GWR enthusiast, so twice shamed.

I dont criticise the alterations made in Tornado. I gather there was a batch built with roller bearings, and the other mods make sense, since at heart it is the original design, albeit with a rethought boiler and some electronics. When they did a performance test I gather it was near spot on with an original A1. So in that respect, hard to criticize the decisions made.

With a P2, I cant help but think you are building a design that forwhatever reasons didnt work out. If they want to make an advanced build, Id avocate building a Tornado 2. Corridor tender, caproti gear, and some of the redraughting ideas Porta came up with. At least they would be building upon a basic design they proved was sound. Or perhaps even a new build A4, which a new build they would stand more chance of getting over 75mph running.

No disrespect to them, I think they are a remarkable bunch of chaps. But It also would be nice to see something a bit smaller and more unusual like a K4. I dont think there are nearly enough smaller locomotives being built, whereas the focus always seems to be on mainline locomotives. Considering in the future the requirement may be more for locomotives suited for hauling on heritage lines, this may prove to be a mistake.

Just my view of course.

 

The P2 plan (so far as has been proceeded - the feasibility study is the main focus at the moment, so I hear) is not really all that different from Tornado. Utilising as much of the common parts and designs as possible between the two classes (including the boiler, tender, and similar), the P2 makes more sense than any other class if you want to build a locomotive that shares a stable with the already built A1 and still has that Va Va Voom for drawing in the crowds.

In a nutshell, yes! But absolutely no different in that respect to the group planning on building a County Tank (GW). The difference is simple. The modern interpretation of the P2 will be designed to fix those problems and make what would be a truly stellar performer for the mainline.

People keep saying "build another A1" or A4 and I just don't see that another member of either class would get the interest in funding that a Gresley P2 would, in spades. Half the battle is getting the covenators on board for a second build, and with a P2 being the most requested by the trust's own covenators, you are effectively much further ahead than they were with Tornado at the start of the A1's own project.

I think it will depend entirely, in years to come, on whether it becomes a blanket ban on steam altogether or on a case by case basis with reliability figures being looked at more and more. However - something which cannot be denied - the inherent advantage of a P2 over any of the Pacifics would be that monstrous adhesion with the eight driving wheels.

Some of the things I've read about the P2s, despite their flaws, whilst on trial, are unbelievable in some respects, and yet the timings are official and there's photographic evidence too! Their penchant for steady running with little worries about hill climbing are staggering, particularly over the Aberdeen line. I refer to Cecil J. Allen and O.S. Nock for the records in various publications.

 

I agree with the K4 Sentiment, that design surely is 'the' Pocket Rocket.

The P2 would be unique (until they build two) in preservation as the only British 'mikado' - Building yet another Pacific or a super pacific is not the answer, most 8P pacifics already generate power well in excess of what that wheel configuration can get on the rails so the only mods worth persuing are ones to increase efficiency and reliabilty and interfacing with the modern rail network and Tornado has addressed these criteria pretty well.
Many of the issues relating to the P2 , Pony truck, Draughting, Valve gear, we're addressed succesfully in Later designs,

the main bugbear remains the long 8 coupled wheelbase, the strength of the design is also its weakness hence all the modelling and testing.
Its a historical Irony that there we're no P2'S around for the likes of Hardy and K.J Cook to have a go at, a bit of Eastern Pragmatism and Wiltshire wisdom may have turned the Grinder into a Glider....

As im so fond of saying the more practical Mikado to build would be the one based on a Britannia with 5ft 3ft or 5ft 6 inch wheels
or go one step further and put a Duke Boiler/3 cylinders/caprotti on that chassis. Boy now that would accelerate

 

Before building i would check networks rails opinion on this gauging issues and would presume be heavy on the track as well.how much would it cost 15 20 million is it worth it when there are unique locos sitting in the nrm which have not run for years which are far more suited to the needs of the preservation sector than another large pacific.

There must be almost 20 8p locos that could run at one time in the uk do we need one more which is effectively a new design any performances will prove nothing about the original as anything can be made to work with modern engineering that was impossible 50 years are.

I dare that leader could now be made to work if enough time was spend on designing out the original problems.

 

A 2-8-2 Duke? Wow! The smaller driving wheels would be a handicap on the modern network - limited to 60mph without special (expensive, tedious, uncertain) dispensation from the authorities, so how about 6' 2" drivers, like a Bulleid pacific or a Standard 5? Class 8MT?

But this is straying a long way from the idea of a new-build V4...

 

Nothing is impossible, but further work on sleeve valves and chain drive on steam locos never happened, further design on draughting, riding, poppet valve gear did.

I dont know whether the V4 had Rocker grates, ashpans, spark arerestors, self cleaning smokebox etc, but if you we're going to build one you would want these on it, its not re inventing the wheel, its just putting on features that we're common place on the last Generation of mainline steam locos in this country...

 

In reply to steamage, maybe at 5' 6' you could get a 75mph dispensation (9f's could do it, 4mt tanks at 5ft 8 could do it no worries)... but its not just about fast running is it..., speed restrictions abound on all but the Best (and busiest) planned mainlines (which even at 75mph are becoming difficult for steam) getting your train away and running at top speed in as short a time as possible(ie acceleration) is just as important in these circumstances.
Increasing the wheel diameter increases the coupled wheelbase which defeats the point, may as well have the new P2 Which in terms of dimensions on paper is very very similar to the Duke...

Back to a V4 - Just big enough for some of the less demanding mainline work, just smallenough for the Heritage sector...makes a lot of sense i think.

 

How about a V2?

Given that the decision appears to have been made that 'Green Arrow' is never to work again (for whatever the stated reasons), how about creating a new V2?

This much-loved class always had a great following, especially, for example, from those fortunate enough to have remembered their totally unique sounds on Waverley Route freights, and a version to the later design with separate cylinder castings - instead of monobloc - complete with outside steam pipes could probably be constructed for far less (of the nation's) money than has already been thrown at its larger relative!

Projects to recreate P2s and V4s are extremely admirable propositions and this writer would in no way decry such efforts (if those concerned are convinced that the money really will be available), but, surely, a V2 would be much more useful in view of its higher route availability and vastly superior versatility?

Just a thought ......

 

Re: How about a V2?

I totally agree with the idea to build a new V2, one of the most beautiful and proportioned steam loco in the world (this is my personal opinion !!).

 

Re: How about a V2?

How can it be cheaper to build a ne V2 than restore green arrow or buy a new boiler fire box and put on the old frames. In a ressesion i think a new build of a existing loco is not a good idea.
There are locos far better suited to preserved lines sitting in musuems rusting on siding than a V2 or V4 .

 

Reading Kevin Robertson's book 'leader: Steams last chance' is extremely illuminating. In a word the answer to the above question was no. There was inherent design flaws with Leader that only total re-engineering would cure. To summarise: The sleeve valves were unsuitable for a steam locomotive that varies engine speed, has excessive vibration etc, the offset boiler was an unsolvable problem with regard to weight distribution, the crank axles and offset drive was unworkable, the fireman's working conditions were intolerable even then, let alone now, the driver couldn't actually stand in his cab because of the restricted headroom, the No1 end was too hot to work in due to the proximity of the smokebox etc etc etc.

Concept was good but the Leader as a solution was an abject failure.

 

Depends really just how far you are prepared to deviate / improve on the original?

For example - the solution to an engine that works at variable speed is to have a constant speed engine, and an intermediate system to provide variable speed and torque at the wheels. You could use - ooh, I don't know, maybe an electric generator. By driving the wheels with an electric motor, there would be no need for a crank axle, removing another of the problem areas. Obviously, the offset boiler is problematic, but if the engine burnt its fuel inside the cylinders, there would be no need for a boiler at all. The greater efficiency of this so-called "internal combustion" process might allow you to only need 8 rather than 12 cylinders without compromising power and tractive effort. That would probably also improve conditions for the fireman - who, because he would no longer directly need to stoke the fire, could join the driver in the cab. It might be worth renaming him in light of his new duties as, perhaps, a "secondman".

Smaller wheels would be possible whilst still maintaining suitable top speed because there would be no unbalanced masses so they could rotate faster. That in turn would enable the cab floor to be lowered, overcoming the problem of lack of space for the driver. It is also possible that the lighter weight of the machinery would enable the whole thing to be supported on 8 wheels rather than 12 without compromising the go anywhere axle loading of the original. Despite the smaller size, the continuous tractive effort would still be about 26,000lb, very similar to the Leader's 26,300lb.

So there you have it - a go anywhere, double ended mixed traffic engine of undoubted Southern pedigree, closely based on the Leader and remaining true to the original design concept, but updated in mostly invisible ways with more modern technology to make it better suited to 21st century traditions. We'd have to think of a numbering scheme for the new build; I'd suggest something in the 33xxx series, though I believe other locos may have used those numbers...

Tom (ducking and running for cover...)

 

I wonder, what is the highest cost of any new build? the patterns that you need to cast parts out of, so would it be possible to use any of the A1 trusts patterns to build a V4? what are the wheel size of an V4, and does any suitable patterns excist? what about cylinders etc , whilst i can see how usefull a V4 would be both on the mainline and for heritage use its only going to be a viable project if there are suitable patterns availible that would enable costs to be kept at a suitable affordable level for times such as we are facing where people wont be able to afford several million poind appeals

 

Castings for a one-off are always going to be an expensive option and serious thought needs to be given to replacing as many as possible with fabrications. It may not be 100% as original but such deviation is not going to affect its performance and characteristics in any way.

 

Question to Ruston in particular - you talk of loads of usefull Loco's sitting in Musuems and the NRM at any one time, and although you're right, how many of them do you think the NRM would be willing to let out at one time, if at all ?.

Just because a Loco is technically preserved doesn't mean its automatically availible for operation, be it mainline or not.

One thing that does concern me about a V4 is how much Mainline work it would potentially get, on the basis it's a class 5 or 6, with smallish wheels, the closest thing in comparison is 61994, how much Mainline work does the Marquess get ?, so far as i can tell it just seems to amount to the occasional foray to Fort William or Kyle and that's about it.

 

Why the obsession with an 8-coupled wheelbase being problematic? Germany and Austria have many hilly lines with sharp curves, and yet they had (figures approximate, owing to the hour) the following 2-10-0s: 7,000 Class 52's, 3,000 Class 50's, 2,800 Class 42 (all 2-cyl), 2,000 Class 44 (3-cyl), 35 Class 43 (2-cyl version of 44), 1,500 Class 58 (3-cyl), as well as 366 Class 41 (2-8-2).

Perhaps the secret lies in the Krauss-Helmholtz 'bogie', in which the pony truck is coupled to the leading driving axle, which has a degree of side-play. I have a feeling that this may have been considered for the P2s, but I do not have time to dig-out the appropriate books, although I am rather more certain that Riddles seriously considered this for the 9Fs.

 

Thing is chaps, looking at this logically, would you build a new P2 for which you have 70% commonality of major components and sundries, and ownership of the main toolings in question, or a V4 for which you would effectively need to start from scratch again as no similar locomotive or locomotive class exists? At least with a P2 certain portions of both the preserved V2 and A2 can be measured up and examined, with most of the rest provided by the work done on Tornado.

A V4 may be useful in purely a route availability sense, and perhaps fuel economy, but in actually building the thing, you'd be starting with effectively a blank piece of paper - not a great starting point.

And if you think about it, a Thompson A1/1 is a better bet than a V4 in terms of what components are available, and what similar engines and toolings are still extant to use in its development.

I fear by saying that, I will be accosted!!!

 

Accosted? Lynched more like. If a Thompson A1/1 ever appeared I'd back convert it to a Gresley A1 or if than wasn't possible, take a gas axe to it.

 

Let's say I built one for private use...! Taking a gas axe to an individual's locomotive might be a tad extreme!

The missing link in the LNER Pacific lineup is, after all, a Thompson Pacific, be it an A1 or an A2 sub class. I'm not saying one definitely has to be built, but it is, nevertheless, a gap in the history of the ECML, and one that can be more easily filled than building a V4 (when you consider the locomotives we have preserved or built which share common parts or toolings).

 

Private use or not, I'd still gas axe it. As for there being a gap in ECML history by not having a Thompson Pacific, that's a gap I can live with quite happily.