Imaginary Locomotives

[AlfaZagato]

Gresley finally allowed the frames to be extended for more footplate on the 'Hush-Hush.'  Hence the extra trailing wheel.  I'd imagine the same concession would have needed to be made if the P2 firebox pushed so far into the cab on the Mountain proposal.   

 

I'd imagine the actual mounting of the extra wheel would be similar, thus technically making the world's one-and-only 4-8-2-2.

[Flying Fox 34F]

A Gresley 4-8-2-2, (4-8-4), would probably be too big for the existing turntables on the ECML.  The 4-8-2 proposal was tight as it was.

 

Paul

[billbedford]

Doncaster built at least two pacifics before there were turntables they would fit on. 

[rockershovel]

On 20/11/2023 at 14:48, AlfaZagato said:

Gresley finally allowed the frames to be extended for more footplate on the 'Hush-Hush.'  Hence the extra trailing wheel.  I'd imagine the same concession would have needed to be made if the P2 firebox pushed so far into the cab on the Mountain proposal.   

 

I'd imagine the actual mounting of the extra wheel would be similar, thus technically making the world's one-and-only 4-8-2-2.

Given the success of the 2-8-4 configuration in last-generation US steam, and the LNER success with high-performance 2-6-2 and 2-8-2 types, one might conclude that;

 

- any further development of 8-coupled locomotives on LNER would be in the direction of a 2-8-4

 

- the LNER 2-8-2 and subsequent BR 2-10-0 types showed that the practical, usable limits of steam on British metals had been reached 

 

- it was also acknowledged that existing 2-8-0, 2-10-0 and 4-6-2 types presented routes and diagrams at the limits of hand firing (ie, with the traditional 2-man crew. Boys Own Paper style accounts of crossing the Drakensberg on gigantic Garratts with 2, or even 3 firemen don't count)

[rockershovel]

7 hours ago, billbedford said:

Doncaster built at least two pacifics before there were turntables they would fit on. 

Isn't that a red herring though? There were obviously means by which these locomotives could be turned where required ?

[billbedford]

1 hour ago, rockershovel said:

Isn't that a red herring though? There were obviously means by which these locomotives could be turned where required ?

Imaginary loco run in an imaginary world. 

[Northmoor]

4 hours ago, rockershovel said:

Isn't that a red herring though? There were obviously means by which these locomotives could be turned where required ?

While also convenient distances apart to change locos and crews, it's probably not coincidental that on the ECML locos were changed at Grantham and Newcastle, both of which have triangles nearby.

[Flying Fox 34F]

A 70’ turntable was installed at Grantham in 1920, just before the H4, (K3), 2-6-0 appeared.  This led to speculation about a pacific being in design.

The triangle at Grantham was commissioned in 1951, after several attempts to stabilize the foundation of the 70’ table had failed.  In the interim period groups of locomotives were worked out to Barkston to turn on the triangular junctions.

Looking at the Grantham triangle, I’m not sure a 4-8-2 would have got round it without track damage.

 

Paul

[rockershovel]

 

[DenysW]

7 hours ago, rockershovel said:

usable limits of steam on British metals

Agreed, of course, but within the largely self-imposed limits that they'd chosen to accept as (probably financial) straightjackets. Thus no mechanical stoking (uses a different size of coal). No wholesale replacement of turntables/reconfiguration of triangles to accept >65' turning. No articulateds, especially not for fast & semi-fast passenger duties. Retention of loose-coupled, unbraked freight wagons. No money for longer passing loops. No wholesale upgrade of couplings to accept 3000 ton loads. I'm sure there are more, but that's the quick list.

[rockershovel]

37 minutes ago, DenysW said:

Agreed, of course, but within the largely self-imposed limits that they'd chosen to accept as (probably financial) straightjackets. Thus no mechanical stoking (uses a different size of coal). No wholesale replacement of turntables/reconfiguration of triangles to accept >65' turning. No articulateds, especially not for fast & semi-fast passenger duties. Retention of loose-coupled, unbraked freight wagons. No money for longer passing loops. No wholesale upgrade of couplings to accept 3000 ton loads. I'm sure there are more, but that's the quick list.

All those things really come under the heading of "technology will be obsolete before it pays for itself" or "doesn't fit in the loading gauge"

[rockershovel]

On 20/11/2023 at 14:48, AlfaZagato said:

Gresley finally allowed the frames to be extended for more footplate on the 'Hush-Hush.'  Hence the extra trailing wheel.  I'd imagine the same concession would have needed to be made if the P2 firebox pushed so far into the cab on the Mountain proposal.   

 

I'd imagine the actual mounting of the extra wheel would be similar, thus technically making the world's one-and-only 4-8-2-2.

Given Gresley's American connections, perhaps he was hankering for a "deckless cab"?

[Northmoor]

5 hours ago, Flying Fox 34F said:

A 70’ turntable was installed at Grantham in 1920, just before the H4, (K3), 2-6-0 appeared.  This led to speculation about a pacific being in design.

The triangle at Grantham was commissioned in 1951, after several attempts to stabilize the foundation of the 70’ table had failed.  In the interim period groups of locomotives were worked out to Barkston to turn on the triangular junctions.

Looking at the Grantham triangle, I’m not sure a 4-8-2 would have got round it without track damage.

 

Paul

Thanks, it was the Barkston "triangle" I was thinking of; I didn't know there was another.

[billbedford]

12 hours ago, rockershovel said:

Given the success of the 2-8-4 configuration in last-generation US steam, and the LNER success with high-performance 2-6-2 and 2-8-2 types, one might conclude that;

 

- any further development of 8-coupled locomotives on LNER would be in the direction of a 2-8-4

 

 

Except that Doncaster designed a series of 4-8-2s after WW2

Edited November 26, 2023 by billbedford

[62613]

1 hour ago, billbedford said:

 

Except that Doncaster designed a series of 4-8-2s after WW2

Just because something is designed doesn't mean it will end up being produced, especially if circumstances change, e.g., nationalisation in this case. I've produced many a concept drawing down the years ("Can you do me a building layout showing the positiions of all the reactors, retorts, etc?")

[billbedford]

3 hours ago, 62613 said:

Just because something is designed doesn't mean it will end up being produced, especially if circumstances change, e.g., nationalisation in this case. 

 

You're mistaken there. The LNER directors decided to live without these imaginary eight coupled locos in favour of some equally imaginary diesels. 

[The Johnster]

I think we've been here before, such is the cyclic nature of this topic.  I'm not convinced that a 2-8-4 was ever viable in the UK.  The point of it is to combine smallish driving wheels and high tractive effort with a wide firebox that could convert water to steam as quickly as the loco could use the steam, and the obvious use for such a loco is heavy fast freight, what the Americans called 'highballs'; by fast, I mean near passenger speeds, 80, 90mph.  But the length limit for main line freight trains in the UK is usually 60 standard wagon lengths, and these can be hauled even fully loaded at up to 60mph, the speed the 10' wheelbase wagons were allowed before 1967 (and frequently faster illegally on the ECML), by mixed traffic or express locos, and these were much easier to find economically suitable back workings for.  There was no need for powerful 2-8-4s.

[Compound2632]

5 hours ago, The Johnster said:

I think we've been here before, such is the cyclic nature of this topic.  I'm not convinced that a 2-8-4 was ever viable in the UK.  

 

Well, not 2-8-4 but 4-8-4:

 

 

[Embedded link to Flickr gallery.]

 

But maybe tank engines are cheating?

[2750Papyrus]

Even our imaginary locomotives should be designed and built to meet the requirements of the operating departments.  F A S Brown wrote that Gresley's 4-8-2 was designed to meet an operating requirement for more East Coast start-to-stop timings in excess of 60 mph, rather than the 50 - 55 mph then current.  This would require faster uphill running, and with heavier trains.  Post-war and into the BR period,  designers such as Peppercorn and Riddles seem to have abandoned the quest for higher power and concentrated more on serviceability and economy.  A published comparison of A1s and A3s/A4s has suggested that express services in this period were more frequent but of 10-12 coaches instead of the pre-war 15ish. There seems to have been little published regarding contemporary operating departments' requirements, but maybe the LNER Board's actions reflected this trend?

[62613]

On 26/11/2023 at 23:40, billbedford said:

 

You're mistaken there. The LNER directors decided to live without these imaginary eight coupled locos in favour of some equally imaginary diesels. 

That's what I said!

[Guest]

On 26/11/2023 at 23:40, billbedford said:

 

You're mistaken there. The LNER directors decided to live without these imaginary eight coupled locos in favour of some equally imaginary diesels. 

And/or maybe even imaginary electrics, had the Woodhead route been extended! 

[Guest]

Another version of my alternate Class 47, in BR two-tone green. This actually looks a little better!  Also with the grey-roofing, you could in a roundabout way describe it as an Anglicised version of the Cuban T975 (albeit with a standard 12-LDA engine): 

 

Edited December 7, 2023 by Guest

[Flying Pig]

55 minutes ago, R. Knowles said:

Another version of my alternate Class 47, in BR two-tone green. This actually looks a little better!  Also with the grey-roofing, you could in a roundabout way describe it as an Anglicised version of the Cuban T975 (albeit with a standard 12-LDA engine): 

 

 

The big what-if of the Sulzer Type 4 story of course is: what if Sulzer had bothered to communicate the experience of SNCF with their 12LVA24 engine to BR?  

 

https://www.derbysulzers.com/1702.html

[The Johnster]

The roof headcode box would have probably prevented some of the draughts that troubled the 47s in their later lives, though when I worked on them in the 70s they were fine...

[Guest]

I have to admit that I am still in two-minds about it. From my understanding, one of the reasons that the Class 50s themselves were fitted with Orange Square MU was because of the amount of wiring they required. Also the initial reason why the second generation BR Type 4s weren't initially specified with multiple equipment was because it was deemed too costly and unnecessary, as it was unlikely to see much use.

 

That being said, when it came to the real Class 47s, of course I know that some were later fitted with Green Circle MU equipment, but would it have been viable to this type of equipment (in this case using Blue Star as standard) retrofitted much earlier on, after having their output de-rated? 

Edited December 11, 2023 by Guest