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The LNER Class P3 - My Idea
Posted: Fri Oct 11, 2024 5:25 am
by 506butlerh
I think the BR Standard 9F from the 1950s was a real missed opportunity, because its 10 driving wheels gave it great power and tractive effort, but it could only be used on freight trains. Attempts to use its abilities on passenger trains usually resulted in failure, unless the train ran at slow, freight-appropriate speeds. So what if there was a loco that had the same/similar power and tractive effort as the 9F, but could actually haul passenger trains at reasonably high speeds too? Enter the LNER Class P3 2-8-2 mixed traffic locomotive, a cross between the standard express passenger 4-6-2 Pacifics and the 9F 2-10-0. But what would it look like? In my "head shed", stands a 9F with slightly larger driving wheels (but not as large as a Pacific), the rear driving axle replaced with a trailing axle, and an overall design that clearly looks like it came out of the mind of Edward Thompson. It would be a development of Gresley's V2 2-6-2, and if designed well might have even achieved the unthinkable BR power classification of 9MT. There would be no need for the 9F, since the P3 matched its freight-hauling ability and unlike the 9F it was more than capable of hauling higher-speed passenger trains (though not as fast as the legendary A4s). I would love to be able to get the design out of my head and onto paper, but unfortunately that is beyond my abilities at the moment.
What do you guys think of the idea?
Re: The LNER Class P3 - My Idea
Posted: Sat Oct 12, 2024 6:13 pm
by Atlantic 3279
I did go through a phase of thinking that a 2-8-2 based on the V2, but with 5' 8" coupled wheels, was something the LNER ought to have built and would have found very useful. Lower axle load than the V2, suitable for mixed traffic, shorter rigid wheelbase than the P2s, and probably still fast enough for the Edinburgh-Aberdeen expresses. The V2 grate, smaller than the P2's, should have made it a less wasteful beast when standing idle in steam or pottering around on lighter duties. Set against that, with smaller wheels its potential for deputising on the fastest trains would not be as great as the V2, and because of the axle spacing requirements for Gresley's 3 cylinder system the possible shortening of the coupled wheelbase compared to the P2 isn't so great as one might first imagine.
We'll never know now of course.
As a footnote, I would add that as I'm English through and through, not American or Australian, not "cool", not plotting like Mr Fawkes to blow up the King, was not christened Guy, and am certainly not in any fashionable doubt about my male gender, I am not a "guy", if you don't mind. I am however happy to be addressed as a man, a gentleman(?), a person, a chap, a bloke, a fellow, or one of the folk.
Re: The LNER Class P3 - My Idea
Posted: Sat Oct 12, 2024 9:04 pm
by manna
G'Day Gents.
The 9F was never found wanting, when it was used on Passenger trains, one was timed on Stoke bank at 90mph ! and with their 'tiny' 5ft wheels, after that 9F's were used on quite a few more fast passenger trains on the ECML. Until BR banned them.
9f''s were also used on the Somerset & Dorset Railway, very successfully, I also believe one was used on the Western Region, The 'Red Dragon'.
Now I live in Australia, and 2-8-2's were the 'Bread and Butter' loco's, they got everywhere (Like the US) speeds here were never high, but some of the lines were very lightly laid.
manna
Re: The LNER Class P3 - My Idea
Posted: Sat Oct 12, 2024 10:12 pm
by Hatfield Shed
The abandonment of the 2-8-2's by Thompson was a boob. The 2-8-2 was used very successfully outside the UK and was the main mixed traffic loco in many territories.
Riddles 9F design was a missed opportunity. Designed as a 2-8-2 with 6' wheels, 300 locos could have been erected instead of the Brits, Clans and 9F. No serious speed restriction for BR's 90mph steam speed limit, ample power for most jobs, and with a 22 ton driven axle load plentiful adhesion. (The obsolete MR idea of small axleload was ridiculous for a mainline power output design, there were thousands of successful 2-6-0, 4-6-0 and 2-8-0 designs in service to do that work.) This is in no way to say the 9F was unsuccessful, but that much more was possible if the investment had been more imaginatively utilised.
Re: The LNER Class P3 - My Idea
Posted: Sun Oct 13, 2024 7:23 pm
by Danby Wiske
506butlerh wrote: ↑Fri Oct 11, 2024 5:25 am
There would be no need for the 9F
I think a heavy freight loco with smaller wheels would still have been necessary. It's difficult to imagine anything with 6' wheels hauling iron ore up to Consett...
The 9F would undoubtedly have been better looking as a 2-8-2, but the BR Standards weren't really designed with aesthetics in mind! The extra adhesion weight was probably the priority.
As an aside - if Thompson hadn't mucked around with the P2s, would they have been classified 9P under BR?
Re: The LNER Class P3 - My Idea
Posted: Sun Oct 13, 2024 10:27 pm
by Hatfield Shed
Danby Wiske wrote: ↑Sun Oct 13, 2024 7:23 pm
I think a heavy freight loco with smaller wheels would still have been necessary. It's difficult to imagine anything with 6' wheels hauling iron ore up to Consett...
The Q7 and O1 were well proven for the job, and then there was the P1 design...
Re: The LNER Class P3 - My Idea
Posted: Mon Oct 14, 2024 12:14 am
by Danby Wiske
Hatfield Shed wrote: ↑Sun Oct 13, 2024 10:27 pm
The Q7 and O1 were well proven for the job, and then there was the P1 design...
Yes indeed - but the BR Standards were intended to replace all of these in the long term. It was only a sudden change of policy towards diesel and electric traction which disrupted these plans...
Re: The LNER Class P3 - My Idea
Posted: Mon Oct 14, 2024 2:58 am
by 506butlerh
Exactly what I thought, those duties that really needed the smaller driving wheels that the 9F had and the P3 would not, would be perfectly served by the many 0-8-0 and 2-8-0 locomotives that the LNER had at their disposal, double-headed if necessary. And after nationalisation there were plenty of ex-LMS or Austerity 2-8-0s to go around. The main uses for the P3 would be faster freights and heavy passenger trains that required the power (eg for steep lines). No need for it to go 100mph+, that's what the A4s were for.
Also, just my opinion here, it is unfortunate that the P2s weren't very good, but I believe the A2/2s were even worse (please enlighten me if I am wrong). In my alternate history they were rebuilt as the first P3s, with new-built examples to follow under Peppercorn and early BR.
Re: The LNER Class P3 - My Idea
Posted: Mon Oct 14, 2024 6:45 am
by XhanLu
Hatfield Shed wrote: ↑Sun Oct 13, 2024 10:27 pm
Yes indeed - but the BR Standards were intended to replace all of these in the long term. It was only a sudden change of policy towards diesel and electric traction which disrupted these plans...
In fact, the BR standards could have lasted well into the 70's and even the 80's had BR not come up with their ill-fated modernisation plan, which, ironically, produced the exact opposite result than what they wanted. Load of diesels and electrics plagued with issues, barely any good ones.
Re: The LNER Class P3 - My Idea
Posted: Mon Oct 14, 2024 9:59 am
by Atlantic 3279
506butlerh wrote: ↑Mon Oct 14, 2024 2:58 am
it is unfortunate that the P2s weren't very good, but I believe the A2/2s were even worse
Who says the P2s weren't very good? The A2/2 rebuilds were undoubtedly far from ideal as a result of Thompson's insistence on retaining, amongst other things, the equal length con-rods of the P2s in his "crusade" to eliminate their 2-8-2 form. The P2s in 2-8-2 form were hampered by the leading pony truck design, which could have been changed at relatively little cost compared to a complete rebuild, but it wasn't. They were also hampered by the still-experimental valve gear originally fitted to 2001, which was replaced after proving troublesome. They were hampered by attempted maintenance at a Scottish works with no previous experience of maintaining locos of anything like that size and complexity. They were hampered by union insistence on retention of the practice of stationing and changing engines at Dundee, when the P2s were intended to run through from Edinburgh to Aberdeen. The retained requirement to station and change engines at Dundee meant that needlessly complex working turns had to be contrived to fill the working day of each P2, and P2s that should have been more fully engaged in hauling heavy trains at reasonably high speed had to stand around for extra periods burning coal, fouling their fire-bars and tubes, filling up their ashpans, waiting to do some work. The consequences for economy and reliability were predictable. It doesn't mean that the design wasn't very good
for the job the P2s were supposed to do. Thompson even refused to allow them to be tried out unaltered (or with new pony trucks) on the heavy wartime trains on the former GN main line, were they could have shown their ability to do the sort of work that they were built for, avoiding the expense of the rebuilds and the loss of availability during the reconstruction process.
My thoughts on the mixed traffic 2-8-2 idea by the way relate to a loco that could have been built instead of some or all of the V2s, and possibly the P2s, i.e, in the mid-late 1930s
Re: The LNER Class P3 - My Idea
Posted: Mon Oct 14, 2024 10:35 am
by Hatfield Shed
Regarding development of a freight loco from the V2, surely I am not the only one who has bunged a 2-8-2 chassis (AHM) under the original Bachmann V2 body to see what it looks like.'Just Right' is my verdict. It's been looking like that for about ten years, other projects for real subjects tend to intrude, so it isn't motorised.
Atlantic 3279 wrote: ↑Mon Oct 14, 2024 9:59 am...Who says the P2s weren't very good?...
There's a test in prospect to scotch that. Hopefully those involved have got it right, and if it can be given an all out main line test it will demonstrate the benefit of its superior adhesion when compared to a UK pacific of equivalent boiler and cylinder power output. There was never any doubt about the traction enhancement when in service. It was detail development that was required, and hopefully the new build has all that covered.
Re: The LNER Class P3 - My Idea
Posted: Mon Oct 14, 2024 12:34 pm
by 506butlerh
I was thinking about how I could make a model of my P3, perhaps an A2/2 on top of a 2-8-2 chassis? I just need to find the right chassis, easier said than done for a locomotive I only just thought of a few days ago. The A2/2s tender doesn’t need to change. Any suggestions on a suitable chassis would be much appreciated.
Re: The LNER Class P3 - My Idea
Posted: Mon Oct 14, 2024 6:34 pm
by Atlantic 3279
Quite as Hatfield Shed says, and With 90 years improvement in metallurgy, tribology, stress analysis at the design stage, and ultrasonic/x-ray examination of forging, castings and welds, there should be far less risk of failures of the heavily stressed driving axles.
Re: The LNER Class P3 - My Idea
Posted: Mon Oct 14, 2024 9:06 pm
by manna
G'Day Gents
There may be the possibility that once the 'NEW' P2 gets running, we may very well see a 2007 climbing 'Stoke bank' at 90mph.
manna