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Gresley and the 2-6-2 wheel arrangement
Posted: Thu Sep 28, 2006 4:29 am
by Pyewipe Junction
Does anyone know the reason for Gresley's attachment to the 2-6-2 wheel arrangement?
I read somewhwere that he had a dislike for 4-6-0s (and built only one class, the B17s). 4-6-0s are inherently more stable at the front at high speeds but are, of course, limited at the firebox end.
It's always seemed strange to me that no-one ever thought of building a light Pacific (I mean something around the 5/6MT mark) before the ill-fated Clans. That way you'd get the best of both worlds.
Surely Gresley wasn't serious about the V4s as an all-purpose mixed traffic loco. With 5' 8" wheels???
Posted: Thu Sep 28, 2006 6:30 am
by Green Arrow
Well, the Australian D57's and H's could keep good speed with MUCH smaller wheels. Small wheels can be versitle. Let's not forget that it was WW2.
Posted: Thu Sep 28, 2006 7:44 am
by Pyewipe Junction
Green:
'good speed' in Austrlai means 35 mph!
Posted: Thu Sep 28, 2006 8:18 am
by Pyewipe Junction
Seriously, can anyone imagine the V4s hauling expresses such as those form Grimsby to London, Norwich to London and on the GC London extension?
Form what I have read about this class it was an abysmal failure.
Posted: Thu Sep 28, 2006 2:22 pm
by richard
Wouldn't the 2-6-2 give more firebox room than a 4-6-0?
I'm thinking of all those GCR 4-6-0s with their shallow fireboxes due to the position of the rear dirving axle.
Richard
Posted: Thu Sep 28, 2006 10:39 pm
by Pyewipe Junction
Richard: yes, you are correct (and you'll see that I made that point in my original post).
But the trade-off is less high-speed stability at the front. V2s were plagued by pony truck problems.
A Pacific, however, gives you the best of both worlds.
Posted: Fri Sep 29, 2006 3:59 pm
by bw1165
I believe the V2s were highly regarded on the GC by the same men who absolutely despised the B17s with a passion.
Are people forgetting the Bulleid light pacifics? Surely, in their rebuilt form anyway, a loco that could have done most jobs on the BR network. Cracking engines, IMHO. And of course Bulleid was from the LNER...
Posted: Fri Sep 29, 2006 4:15 pm
by richard
I thought the Bulleids (all three of his big SR engines) were noted for their slippery feet?
Interestingly, Bulleid had a lot to do with the P2s - and they probably had the best adhesion of any British express passenger design...
Richard
Posted: Fri Sep 29, 2006 7:00 pm
by LNERandBR
The Bulleid Percifics are light footed. It seems the SR carn't build loco's with good adhesion (The Schools Class 4-4-0 comes to mind)
The V2 was an exhalant loco. They didn't have stability problems as long as the track was in good condidtion. The LNER experenced probelms with the fornt pony truck during and after the war when track mantanace was not up to scratch.
Anyway Gresley didn't have a thing with the 2-6-2 wheel arragement. Look how many locomotive classes he produced and see how many of them start with a V.
Posted: Sat Sep 30, 2006 8:04 am
by Kyle1987
i think when it comes down to it that the V2s were good locomotives when properly maintained, as well as being very pleasing to the eye which was the case for all of gresley's locomotives
Posted: Mon Oct 02, 2006 9:05 am
by Pyewipe Junction
I think some of the replies to my post have missed the point of my question.
To answer one comment - Gresley designed all four of the LNER's 2-6-2s (three if you count the V1s and V3s as one class). And two of them were tender locos - unique in the UK.
I was in no way denigrating the V2s. I remember them fondly on the March - Sheffield leg of the Harwich - Liverpool boat train. And don't forget they were the engines that 'won the war' because of their legendary performances during WW2.
But let's not forget they had the TE of an A3, so why didn't Gresley build them as Pacifics and avoid problems with a pony truck?
Don't forget also that Gresley also built the only two classes of 2-8-2 tender engines. This indicates to me that he had an attraction to pony trucks. Perhaps we'll never know why.
Posted: Mon Oct 02, 2006 10:21 am
by Kyle1987
I think again it comes down to maintainance. Most of the problems encountered with the pony trucks occurred during and shortly after the war; when track and loco maintainance was not high on the agenda. However, during times of peace (which was in all but 2 years of Gresley's reign) few problems were encountered (though some did still occur), making the issue of the pony truck almost non-existant for Gresley. So maybe he just didn't feel there was a problem with building his locos with a pony truck.
Posted: Mon Oct 02, 2006 9:10 pm
by Colombo
A very good reason for building a 2-6-2 rather than a pacific, would be that the prairie loco could be turned on a smaller turntable. This was very important at a time when the 70 foot turntables were only available at a limited number of locations on the ECML. The shorter wheelbase greatly increased the usefullness of the locomotive.
Also the three cylinder design gives a greater tractive effort and a smoother flow of power than a two cylinder design. Another important factor influencing route availability was the hammer blow of the locomotive. Hammer blow is the additional downward force generated by the out of balance rotating and reciprocating masses in the engine at speed, which has an impact on bridge loadings. A three or four cylinder engine gives less hammer blow than a two cylinder engine of the same weight and therefore can have a wider route availability.
Add to these benefits the wider firebox that can be fitted to give an increased rate of combustion and steam evaporation over a narrow firebox, even with poorer coal, and the advantages of the design are clear.
Colombo
Posted: Mon Oct 02, 2006 11:38 pm
by Pyewipe Junction
Sorry Colombo, don't entirely understand that one.
My 1950 locoshed book shows the V2s only being allocated to ECML and GC London extension sheds (and possibly March). They were also RA9.
The number of cylinders isn't an issue either - I assume that a Pacific of the same TE as the V2s would be a three-cylinder loco.
Can I ask a question - is there a 'hands off' Gresley policy on this site? If so I post any more items to do wth him!
Posted: Tue Oct 03, 2006 12:16 am
by Green Arrow
How dare you insult Nigel Gresley!
Some V2's did come out as Pacifics, as Edward *cough*Gresleyhater*cough* Thompson rebuilt some.