Q&A

[Mickey]

Bit of a dumb question but why were some pre-grouping railway passenger coaches built as 12-wheelers and the rest built as the more usual 8-wheelers?. I presume the 12-wheelers were built to hold more weight maybe so was that the reason why?.

[Hatfield Shed]

Bogie design was advancing quickly at the time, and 'everything' was being tried to secure the best ride for passengers. Eventually sound engineering precepts of least weight, complexity and cost, fairly rapidly killed the six wheel bogie as four wheel bogie design developments did all that was required. Gresley's GNR carriage and wagon team to the fore in all this, a design legacy which wasn't obsolete on BR until the 1970s.

[Mickey]

Thanks for your reply Hatfield Shed. I thought maybe those 12-wheelers were built maybe for a greater 'distribution of weight' and were possibly used for I assumed heavier coaches such as 'Dinning/Pantry cars' and a half passenger coach with a brake/guards compartment included because I am assuming maybe mistakenly that those types of passenger rolling stock were maybe built heavier than a 'normal' 8-wheeler passenger coaches but as I said that is just an assumption on my part anyway I kind of liked the look of the odd pre-grouping 12-wheeler stuck in amongst a rake of 8-wheelers from pictures from the 1890s-1930s.

[Hatfield Shed]

...I thought maybe those 12-wheelers were built maybe for a greater 'distribution of weight' and were possibly used for I assumed heavier coaches such as 'restaurant/kitchen cars' and 'sleeping cars' because I am assuming that those types of passenger rolling stock were maybe built heavier than a 'normal' 8-wheeler passenger coaches...

That may well have been the thinking at the time. What I recall of carriage development was that the late Victorian rigid wheelbase vehicles typically maxxed out between 6 to 7 tons of tare weight per axle, and as the bogie carriages built as replacements became longer and heavier they increasingly received 3 axle bogies for much the same axle load. But from the early 1900s onwards twin axle bogies were being used on carriages with tare weights in the 35 to 40 ton range. I would surmise that improved design of both the carriage structure and running gear had demonstrated that greater axle loads were possible with no resulting disadvantage, and a considerable reduction in cost.

Perhaps there's a specialist who can provide more information.

[harvester]

"Gresley's GNR carriage and wagon team to the fore in all this, a design legacy which wasn't obsolete on BR until the 1970s." quote Hadfield Shed.

A friend who worked on refurbishing rolling stock in the 1970/80 often told me that engineers working on new bogie design often asked each other the question "is it as good as a Gresley"

[billbedford]

...Eventually sound engineering precepts of least weight, complexity and cost, fairly rapidly killed the six-wheel bogie as four-wheel bogie design developments did all that was required. Gresley's GNR carriage and wagon team was to the fore in all this, a design legacy which wasn't obsolete on BR until the 1970s.

Except, the double bolster arrangement on the "Gresley" bogies was more complex than earlier designs. Its design was patented and presumably invented by Spencer-Moulton Ltd who were spring makers.

[Hatfield Shed]

There's complexity and then there's complexity. A one third reduction in unsprung mass by having only two wheelsets instead of three is a simplification of the design problem. And then while the bogie mechanism design may be more complex than such as a two axle Fox type bogie, it's what benefit is obtained for that increased complexity and consequent first cost, when compared to the simpler options, that matters in the final assessment. And economic context is all.

I have fought this one out many times in a very different technology, and shared notes with many others in a range of engineering disciplines, and it is a very common experience. Sometimes the more complex higher first cost approach is justified. On other occasions, simpler and cheaper is the way: I have done both, the latter for a short term stop gap product, within an organisation that typically went the high reliability, robust and reusable path for decades of reliable and readily maintained service.

All time favourite 'war story' that well illustrates the import of the economic context. The Royal Navy was asked in WWII why it insisted on such a complex and thus slower and more expensive construction for its submarine conning towers, which were made in bronze; while the very effective Kriegsmarine U boat was proving to work all too well with its lower cost all steel construction.
RN opinion, 'That's cheap and nasty'.
Reply, 'And is there a better description for a weapon to prosecute a war?'

I am deploying the life experience at present: in the midst of prodding at the tech refinement benefits relating to a PV, battery storage, air sourced heat pump and management system integration for our home, and have already bent several potential suppliers out of shape by asking 'awkward' questions...

[4812]

It had nothing to do with ride-quality but was a set of GER suburban carriages not given 6-wheel bogies because of the short length of the company's locking bars? And on the GNR was this perhaps also the reason for the 11ft 9in wheelbase of some of Gresley's early 4-wheel bogies?

[Mickey]

I was watching 'on line' some old film of the 1967 Grand National the race where a lot of the runners and riders fall at one of the fences (I recall watching it on the telly at the time) anyway when the horses approach the fence that many of them fall at in the background is a rake of blue/grey B.R.Mk2 coaches on the railway beside the race course but just glimpsed is a steam loco tender with loco smoke streaming back over the tender so does anyone know what the class of loco mite be?. I tried watching the race several times but I can't make out what the loco mite be for definite?.

Being that the Grand National is at Aintree in the Liverpool area it's on the London Midland Region of B.R. so maybe it's a 'racing day special' worked by a black 5 or possibly one of the last Britannia's still in traffic in 1967 or maybe an 'outside bet' a 'race day excursion' originating from the North Eastern Region worked by one of the last ex-LNER B1s left in traffic in 1967?. Strangely enough the vague shape and outline of the loco concerned which is just about seen on the poor quality black & white film for a couple of seconds does look a bit like a B1?.

[Hatfield Shed]

The 'Foinaven' Grand National when most of the field were derailed, many of the horseboys fell off and some ran away, and the 100:1 outsider won it.

As for the interesting aspect, from the blurred panned fillum, black taper boiler with rather a slim chimney and a smallish tender. A 4MT or smaller 2-6-0. perhaps? There's relatively few classes still working on LMR by this date, so not many likely candidates.

[Mickey]

Interesting Hatfield Shed so that loco may well have been just a loco being used for shunting in those carriage sidings or for working ECS trains in that area?. It was probably pushing it a bit of me thinking it was one of the last ex-LNER B1s left in traffic in 1967 originating off the North Eastern Region after working a 'race day' special across to Aintree?

As for the actual horse race it's self I remember actually watching it on the telly in real time back in 1967 mind you I was only 10 years old at the time!.

[Hatfield Shed]

There must be some good still photographs 'out there' which would answer the question, but searching for them is tedious...

[Mickey]

Purley a guess on my part but when trying to decipher what class of steam loco it was I thought looking at the poor quality and almost out of focus black & white television pictures that possibly it may have been a B.R. Standard 2 2-6-0 that were allocated to the London Midland Region because of it's black smallish 'squarish' shape anyway apparently 13 standard 2s 2-6-0s were still in traffic in 1967 and probably would be seen in carriage sidings on ECS jobs although those remaining 13 Standard 2s of the class were all withdrawn during 1967 making the class extinct.

[rockinjohn]

Hi yes Willesden(1A)did indeed have 8+"standard"2MT tender engines on its books @ the near end of steam,mainly for as you say ECS out of Euston,and a class member turned up on the Southern @ Guildford around the same time finding itself on a couple of "tours" along side its other uses.

[65447]

...I thought maybe those 12-wheelers were built maybe for a greater 'distribution of weight' and were possibly used for I assumed heavier coaches such as 'restaurant/kitchen cars' and 'sleeping cars' because I am assuming that those types of passenger rolling stock were maybe built heavier than a 'normal' 8-wheeler passenger coaches...

That may well have been the thinking at the time. What I recall of carriage development was that the late Victorian rigid wheelbase vehicles typically maxxed out between 6 to 7 tons of tare weight per axle, and as the bogie carriages built as replacements became longer and heavier they increasingly received 3 axle bogies for much the same axle load. But from the early 1900s onwards twin axle bogies were being used on carriages with tare weights in the 35 to 40 ton range. I would surmise that improved design of both the carriage structure and running gear had demonstrated that greater axle loads were possible with no resulting disadvantage, and a considerable reduction in cost.

Perhaps there's a specialist who can provide more information.

It's more than possible that the reduction from 3 axles to 2 was brought about by the wider adoption of all-steel wheels and axles, rather than the use hitherto of wooden-centred Mansell wheels which, by virtue of their physical characteristics, could not carry the same load per axle let alone increased loadings.