Gresley V4

A point not noted (apologies if it has been) is that the V4 was seen as the tender version of the V3 2-6-2T design and the latter had proved useful in both Newcastle and Scotland where they performed on suburban services and light freight duties including trip workings. Reports suggest that they might have been the standard mixed traffic loco but Gresley's early demise led to Thompson's regime and the return to the "standard" 4-6-0 configuration that became the standard network loco that Gresley had intended the V4 to be.

 

That may well be true as it happens. Smaller classes did not tend to have spare boilers on the LNER. For example, and off the top of my head, classes W1, A2/2 and as you say V4 all suffered from small boiler pools (W1 had only two boilers - one before and after its major rebuild - and was always waiting on it to be repaired before a return to service), the A2/2s later getting fitted with Thompson and Peppercorn boilers in various forms to improve their mileage.

This was the A2/2s single biggest fundamental weakness, particularly around the late 40s and early 50s when the unique Wolf of Badenoch boiler went for scrap. Far more than the issues with frame cracks and steam leaks was the time spent waiting for a boiler to become available.

I don't know about the V4s pool of boilers but it cannot have been more than three and was in all likelihood probably only the two originally made for the two locomotives - and the two boilers were not identical in any event (one had thermic siphons fitted - I don't know if this would have been able to be fitted to the other V4).

Absolutely, totally agree with this. Some designers and drawing offices more restricted at times than others whether by economic or physical factors (e.g. costs and material availability).

Completely agree.

Absolutely, and equally different designers within the same company can disagree on design options.

It has always interested me that the argument for the round topped boiler on the LNER was that it was less complicated and easier to manufacture than the belpaire - accepted - but then the LNER goes against this same argument and introduces complexity as opposed simplicity where the valve gear is concerned (two cylinders, outside valve gear as opposed conjugated across three cylinders).

If the entire aim was to produce easy to maintain locomotives then undoubtedly the two cylinder option gets the nod, as it did under Thompson and then Peppercorn and was of course the same on the GWR, LMS and SR.

However as we know it's also a trade off for performance and undoubtedly (when well maintained) there is nothing materially wrong with the conjugated valve gear, which produced locomotives of excellent performance ability.

 

There were only 2 V4 boilers, and for a period only one when the steel firebox/ thermic syphons was converted to a standard copper.
If the entire inside motion is maintenance free ( in theory) then three cylinders is better than two as its less stressing to frames, axleboxes etc... In practice this was never quite achieved ( Cough oil bath anyone ? ). again its a trade off

 

Not necessarily - as has been discussed on here before, a three cylinder loco has worse starting performance than a two cylinder loco of notionally equivalent tractive effort, on account of the fact that in either case, on starting there may only be a single piston that is receiving steam, but that piston is smaller in area (and therefore the steam imparts less force) than in a two cylinder design. The disadvantage lasts until there has been one complete wheel revolution, at which point the smoother torque curve of a three cylinder design becomes a theoretical advantage.

Tom

 

Yes Tom, but the discussion was about maintenance, not starting tractive effort. Now maintenance could mean the daily checking and oiling round ( and I think two outside cylinders has it here) or how f*cked the thing is after 50,000 miles, suspect a V4 Might have it over a B1 there.

 

Yes but it goes further than that. How long does it take to take apart and put back together a B1 compared to a V4 when the time to shop a locomotive comes?

That was the big point Thompson made on the LNER when arguing for two cylinders instead of three for the small and medium sized locomotives. If you need to remove just one cylinder on a locomotive, which takes longer, and is more involved, the B1 or the V4?

The V4 has a monobloc by the way...

It is not as simple as "4-6-0 and two cylinders bad" or "2-6-2 and three cylinders good" or vice versa. I am sure the whole story on the LNER was never as simple as the Gresley/Thompson debate sometimes makes it out to be. There's so many factors to consider than an objective view on the whole thing needs a step back to consider the whole circumstances.

 

A good point, but if it goes another 25,000 miles before it needs shopping.
If it had been a bigger class perhaps Thompson would have just changed them to 2 cylinder Machines...

 

Is there any footage of a V4 anywhere?

 

Those railways produced a fair number of multi-cylinder locos so your argument is somewhat weak on that point IMO.

 

Indeed - the SR in particular built 2, 3 and 4 cylinder locos as the occasion demanded. They even built essentially 2 and 3 cylinder variants of otherwise identical locos (N / K / U and N1 / K1 / U1) and the three cylinder variants had both conjugated and independent valve gear. I suspect if you really wanted to delve into the relative maintenance costs of two and three cylinder locos while isolating as many other variables as possible, SR maintenance records would be the place to look. Holcroft covered the operational comparison between N and N1 but I can't remember much about relative maintenance costs.

Tom

 

Again and as before I was referring to the small and medium size locomotives for which they outnumber the three and four cylinder locomotives by an absolutely ridiculous amount. Saints? Halls? Granges? Night Owls? Black Fives? 8Fs? Austerity locomotives? The Southern's King Arthurs, Goods Arthurs, huge variety of 0-6-0s from every railway? Those just off the top of my head and undoubtedly there's hundreds of classes and thousands more steam locomotives besides.

If you were to look at the break down of how many three cylindered and four cylindered locomotives there were in the small and medium size steam locomotives in Great Britain you'd see the the proportion of two cylinder to three and four cylinder is wildly imbalanced.

Weren't a number of those converted to 2 cylinder though Tom...?

 

No, they kept the same numbers of cylinders, but the ones built with conjugated valve gear were subsequently converted to three independent sets of valve gear. My point though was that if you wanted generically to do a study in comparative maintenance costs between two and three cylinders, comparing works records of, say N and N1 would probably be as close as you could get to a "controlled study" in which the number of cylinders was the main variable.

Tom

 

Fair point Tom.

 

Thee LMS were looking at all 2 cylinder designs by 1947. With better balancing other issues had become not needed. Black 5 vs Jubilee? Stanier brought a lot from Swindon and added to an already sophisticated practice. History was written by GWR fans who just said rubbish to all else. OK Claughtons heavy on coal, but better metallurgy and balance, and they weren't all bad etc

 

OT but it gets my goat, and we've been through this before: The GWR 47xx were known as "Night Hawks" - "Night Owl" is a tautology; owls are nocturnal so don't need the adjective "night".

 

I don't want to prolong the thread drift, but those statements should not be allowed to pass without comment.
Not all owls are nocturnal.
At http://www.didcotrailwaycentre.org.uk/locos/4709/4709.html the people who are building one say "Only nine of these huge locomotives were built, primarily for fast overnight freight work, earning them the nickname 'Night Owls'. "

 

So...we good?

 

Just to be clear, the V4's were NOT designed for the West Highland - they ended up in Scotland because one was already there on account of its steel firebox. With 5'8" wheels and three cylinders they would have been capable of speeds in the low 80's, more than adequate for any duty they'd have been likely to do. With no war its likely they would have become the standard express loco on the GE section as well as being perfectly capable to replace the many aged 4-4-0's and the various small classes of not-very-efficent 4-4-0's and 4-4-2's of which the LNER had far too many - and which in the event were replaced by B1's and V2's .

Gresley still needed to design something like the K1 for freight though - and he had intended to as far back as 1926 but was stopped by cost considerations. As someone mentioned elsewhere H.G. Ivatt finally shot down the idea that you carry on with Victorian 0-6-0's because that is what your father and grandfather had done!

 

I would have considered "Bantam Crow" as a name suggestion.

 

An express loco with 5'8 drivers ?, I can't imagine wheel diameter would make that much difference to overall weight, which I assume was the biggest factor for the Great Eastern, so why woulden't you go for a design with drivers well into 6' ?, did any design with drivers under 6'0 regularly hit 80MPH plus ?.