OO gauge GWR Mogul and Prairie

[Ian Hargrave]

51 minutes ago, Miss Prism said:

 

Ah, yes, I see 8101 now. With 5'8" drivers I bet!!

 

 
8104 was a constant performer on the Vale of Neath line during the 1950’s .Seen most mornings on my way to school.  It will be interesting to see if Dapol get this one right ! 

[Miss Prism]

8104 in 1955 with red-background plates

[Ian Hargrave]

10 minutes ago, Miss Prism said:

8104 in 1955 with red-background plates

Really ? Looks an ex works job.Where’s the front number plate  ? And I’d like a look at the shed plate. I believe she was an 87A Court Sart  loco. But I must check that I think.

[Miss Prism]

6 minutes ago, Ian Hargrave said:

Really ? Looks an ex works job. Where’s the front number plate  ? And I’d like a look at the shed plate.

 

I think it probably is ex-works, but I question the date given - red background plates had long ceased on new paintjobs by 1955. Front number plate has gone walkies it would seem. Or, the date is more like 1949/50, with the loco first appearing in a non-GWR scheme and awaiting delivery of the smokebox number plate. I will amend the gwr.org.uk caption to be less certain! One thing is for certain though - the plates are red background. It's not a good photo, shed plate detail is indiscernible.

 

[The Johnster]

If we remove some of the confusion, not all but some, by only discussing locos that survived into BR era, the large prairies are as follows:- 

 

a) classes with no.2 std boiler:-

 

1) 5101, 5’8” driving wheels, 180psi boiler, rebuilds of Churchward 31xx class and new builds to same spec.  Lasted until 1965, some preserved. 279 built.  Numbers in 51xx and 41xx series, some 51xx and all 41xx new builds, last built 1950.  RTR from Hornby and Dapol, discontinued Airfix/Mainline model retooled by Hornby.  Southeastern kit. 

2) 61xx, visually identical to 5101, 220psi boiler.  70 built. One prototype given 5’.6” drivers.  One preserved. RTR from Hornby & Dapol. 
 

3) 81xx, Collett rebuild of 5101. Spec as 61xx but 5’6” drivers. 10 built.  Extinct. No current RTR but Graham Farish lo-fi from 1950s/60s can be sourced 2h. 


b) classes with larger no.4 std boiler (none of these have ever been available as RTR models and there are no known intended models, all prototypes extinct):-

 

1) 3150, 180psi boiler, 5’8” driving wheels.  59 built.  Extinct by 1961.  Southeastern kit. 
 

2) 31xx, 220psi boiler, 5’3” drivers.  Collett rebuild of 3150 (confusion can arise as number series re-used from Churchward 31xx class).  Extinct by 1960.  Can’t offhand remember who does/did a kit for this loco.  
 

The background to all this is that Collett clearly thought he could make worthwhile improvements to the two original Churchward classes, and the first stage of this was the 61xx for London area suburban work where better acceleration from stops was needed.  The smaller wheeled 81xx was for the hillier Birmingham area.  
 

Then he turned his attention to the 3150s, intending to rebuilt the entire class to his 31xx spec., but the effects of German foreign policy between 1939 and 1945 prevented this.  Post-war, under Hawksworth, the idea was shelved and more 5101s were built instead.  
 

Roof profile varied on the no.2 boilered locos, as did chimneys and safety valve bonnets.  Some 61xx had LT tripcpck apparatus for working on the Mainline & City services.  All the no.4 boilered locos had high-roof cabs. 
 

 

 

[Ian Hargrave]

18 minutes ago, Miss Prism said:

 

I think it probably is ex-works, but I question the date given - red background plates had long ceased on new paintjobs by 1955. Front number plate has gone walkies it would seem. Or, the date is more like 1949/50, with the loco first appearing in a non-GWR scheme and awaiting delivery of the smokebox number plate. I will amend the gwr.org.uk caption to be less certain! One thing is for certain though - the plates are red background. It's not a good photo, shed plate detail is indiscernible.

 

Agree 1955 is too late. It was indeed…I’ve checked….an 87A loco and was a regular performer and obviously a favourite.Maybe because it had that extra clout ,considering some of the gradients on the line. Not that the loadings were heavy…rarely more than 4 up corridor stock of a variety of both vintage and origin.It remains to this day image firmly printed in my mind.

[exet1095]

26 minutes ago, The Johnster said:

If we remove some of the confusion, not all but some, by only discussing locos that survived into BR era, the large prairies are as follows:- 

 

a) classes with no.2 std boiler:-

 

1) 5101, 5’8” driving wheels, 180psi boiler, rebuilds of Churchward 31xx class and new builds to same spec.  Lasted until 1965, some preserved. 279 built.  Numbers in 51xx and 41xx series, some 51xx and all 41xx new builds, last built 1950.  RTR from Hornby and Dapol, discontinued Airfix/Mainline model retooled by Hornby.  Southeastern kit. 

2) 61xx, visually identical to 5101, 220psi boiler.  70 built. One prototype given 5’.6” drivers.  One preserved. RTR from Hornby & Dapol. 
 

3) 81xx, Collett rebuild of 5101. Spec as 61xx but 5’6” drivers. 10 built.  Extinct. No current RTR but Graham Farish lo-fi from 1950s/60s can be sourced 2h. 


b) classes with larger no.4 std boiler (none of these have ever been available as RTR models and there are no known intended models, all prototypes extinct):-

 

1) 3150, 180psi boiler, 5’8” driving wheels.  59 built.  Extinct by 1961.  Southeastern kit. 
 

2) 31xx, 220psi boiler, 5’3” drivers.  Collett rebuild of 3150 (confusion can arise as number series re-used from Churchward 31xx class).  Extinct by 1960.  Can’t offhand remember who does/did a kit for this loco.  
 

The background to all this is that Collett clearly thought he could make worthwhile improvements to the two original Churchward classes, and the first stage of this was the 61xx for London area suburban work where better acceleration from stops was needed.  The smaller wheeled 81xx was for the hillier Birmingham area.  
 

Then he turned his attention to the 3150s, intending to rebuilt the entire class to his 31xx spec., but the effects of German foreign policy between 1939 and 1945 prevented this.  Post-war, under Hawksworth, the idea was shelved and more 5101s were built instead.  
 

Roof profile varied on the no.2 boilered locos, as did chimneys and safety valve bonnets.  Some 61xx had LT tripcpck apparatus for working on the Mainline & City services.  All the no.4 boilered locos had high-roof cabs. 
 

 

 

You’ve missed the 5100s, originally 3100s, but renumbered in the 1920s. 5100 and 5110-49.

The 5101s were not rebuilds, but new engines. It’s all in the RCTS book.

 

[exet1095]

36 minutes ago, Miss Prism said:

 

I think it probably is ex-works, but I question the date given - red background plates had long ceased on new paintjobs by 1955. Front number plate has gone walkies it would seem. Or, the date is more like 1949/50, with the loco first appearing in a non-GWR scheme and awaiting delivery of the smokebox number plate. I will amend the gwr.org.uk caption to be less certain! One thing is for certain though - the plates are red background. It's not a good photo, shed plate detail is indiscernible.

 

Read the RCTS book - Dapol clearly has.

[Ian Hargrave]

16 minutes ago, exet1095 said:

Read the RCTS book - Dapol clearly has.

17 minutes ago, exet1095 said:

Read the RCTS book - Dapol clearly has.

As far as I can see,the 81XX….which is what we are talking about is being produced by Dapol in BR Green livery and not black. ….unless I’m missing something,Hattons list being a lengthy one . I’m curious,as @MissPrism’s image is a works photo as which WR works this is . The red backed plate phenomenon was not long lasting and 1955 was the cusp of the WR going green mad.

 

 

[Coach bogie]

https://railsofsheffield.com/products/Dapol-4s-041-008-large-prairie-3146-gwr-green-great-western-steam-locomotive

 

Really pleased with the announcement of the square front end releases coming early next year. I have a half finished Wills which I shall now abandon. Pointless continuing as I can use the wheels and motor in something else.

 

Some of these had outside brake rods, which I can add myself.

 

Nice one Dapol.

 

Mike Wiltshire

[Miss Prism]

3129 at Dawlish. I'm guessing c 1925.

 

 

[jamieb]

22 hours ago, Ian Hargrave said:

 
8104 was a constant performer on the Vale of Neath line during the 1950’s .Seen most mornings on my way to school.  It will be interesting to see if Dapol get this one right ! 

The fact that there is no sample photo of the 81XX suggests to me that the wheels will be the correct diameter and this variant is still awaiting a completed sample 

[Ian Hargrave]

10 minutes ago, jamieb said:

The fact that there is no sample photo of the 81XX suggests to me that the wheels will be the correct diameter and this variant is still awaiting a completed sample 

I sincerely hope you are right. I wish I shared your confidence.

[exet1095]

44 minutes ago, Ian Hargrave said:

I sincerely hope you are right. I wish I shared your confidence.

5’8” in 4mm is 22.67mm. 5’6” is 22m.

What is the wear tolerance on tyres? 
just curious; I’m not sure that I could spot any error at normal viewing distance. Much more exciting is the possibility of square drop ands and a high-roofed cab.

 

Paul

[Ian Hargrave]

10 minutes ago, exet1095 said:

5’8” in 4mm is 22.67mm. 5’6” is 22m.

What is the wear tolerance on tyres? 
just curious; I’m not sure that I could spot any error at normal viewing distance. Much more exciting is the possibility of square drop ands and a high-roofed cab.

 

Paul

An increased power output and smaller coupled wheels was ….as was the case with the Grange which saw freight haulage on the route…..a reason for the use of 8104 on the Vale of Neath. That’s why I hope Dapol give a nod in the right direction. I’m being nit picking I know but having shied away from their first iteration due to the matter of the trailing bogie axle spring I hope they make amends by  getting this right dimensionally 

[Clearwater]

Am I misremembering but did Dapol also plan to do the 3150 series?

[The Johnster]

The 61xx/5101 mech would work for a 3150, but the rest would have to be a completely different tooling; the locos are different in almost every dimension.  I'm interested to see how they cope with an 81xx, as simply putting smaller 2mm smaller diameter driving wheels on it will simply result in a 61xx/5101 with buffers out of alignment by 1mm, and that is not quite the same thing as an 81xx.  Neither is 1mm packing between the chassis and the bodyshell; that will get the buffers the right height but there will be a 1mm gap between the top of the cylinders and the bottom of the running plate, three inches scaled up and quite noticeable.  The 'sit' of the boiler is 3" lower on and 81xx.

 

I wouldn't be fooled by a simple renumbering exercise with the excuse that high mileage wear on a 61xx/5101's drivers is not far off new for an 81xx; if you have both models on your layout, you want the 81xx's wheels to be visibly smaller, and your 61xx/5101's wheels not to be on wear limits with vestigial tyres.

 

I can't offhand recall Dap saying that ther were thinking in terms of a 3150, but I hope so, for reasons I'll come back to in a minute.  Mind you, I don't recall them talking  about an 81xx either; sometimes it's nice when things turn up unexpectly from left field...  A 3150 would be move in the direction of what is a major wishlist loco for me, Collett 1938 31xx no.3100, allox TDU from 1946 for the post-war resumption of the daily Porthcawl-Cardiff commuter train, the 'Residential', which it worked until it's withdrawal in 1957 following a 'heavy contact' with the buffers at Porthcawl.  The 'Residential' had been handled pre-war by a succession of Bulldogs, not the usual fayre for a South Wales coalfield shed, but Tondu had 44xx as well!  And banging on about my wishlist items works for me with Dapol, as they have relented and put the ex-Lionheart Diagram N autotrailer through the 4mm ray after me reminding them every so often over the last eight years or so...

 

3100 was the doyen of a class of five, and was rebuilt from a 3150.  The difference was a 220psi boiler and 5'3" drivers, which will be even more of a drop in size than between a 61xx/5101 and a 81xx and again require an new body tooling.

 

The problem with GW engines is that they are all the same except when they are different, and they are in fact all different in subtle and devious ways.  When you get used to them you can identify the difference between a Grange and a Hall front-on from about half a mile away; the sit is different, it's only 2" but it is discernable.  Boiler pitch is determined by wheel diameter, so for a no.4 the highest were the City/Atbaras and Churchward Counties, and the lowest the Aberdares and 8-coupled tanks.  3150s were the same in that respect as the 43xx moguls, but the moguls had a longer low section of running plate ahead of the smokebox saddle, so the proportions were different, a mistake I made during my ongoing and occasional attempts to kitbash 3100 out of RTR bits from an Airfix 61xx and Mainline 43xx and 56xx bodyshells.

[Coach bogie]

6 hours ago, The Johnster said:

3150s were the same in that respect as the 43xx moguls, but the moguls had a longer low section of running plate ahead of the smokebox saddle, so the proportions were different, a mistake I made during my ongoing and occasional attempts to kitbash 3100 out of RTR bits from an Airfix 61xx and Mainline 43xx and 56xx bodyshells.

 My 3150 is made from redundant cast and nickel mogul and prairie parts. The surprise came with the cab and bunker that required spares from a 42/52/72XX. The 51/61xx cab bunker is too small and the cab profile wrong but is exactly the same as the big freight tanks....well against to the plan I was using. Most of the time you will find this model on my friends Devon layout banking freight trains. His subtle way of asking if I will make one for him. 

 

Mike Wiltshire

 

[jamieb]

7 hours ago, The Johnster said:

The 61xx/5101 mech would work for a 3150, but the rest would have to be a completely different tooling; the locos are different in almost every dimension.  I'm interested to see how they cope with an 81xx, as simply putting smaller 2mm smaller diameter driving wheels on it will simply result in a 61xx/5101 with buffers out of alignment by 1mm, and that is not quite the same thing as an 81xx.  Neither is 1mm packing between the chassis and the bodyshell; that will get the buffers the right height but there will be a 1mm gap between the top of the cylinders and the bottom of the running plate, three inches scaled up and quite noticeable.  The 'sit' of the boiler is 3" lower on and 81xx.

 

I wouldn't be fooled by a simple renumbering exercise with the excuse that high mileage wear on a 61xx/5101's drivers is not far off new for an 81xx; if you have both models on your layout, you want the 81xx's wheels to be visibly smaller, and your 61xx/5101's wheels not to be on wear limits with vestigial tyres.

 

I can't offhand recall Dap saying that ther were thinking in terms of a 3150, but I hope so, for reasons I'll come back to in a minute.  Mind you, I don't recall them talking  about an 81xx either; sometimes it's nice when things turn up unexpectly from left field...  A 3150 would be move in the direction of what is a major wishlist loco for me, Collett 1938 31xx no.3100, allox TDU from 1946 for the post-war resumption of the daily Porthcawl-Cardiff commuter train, the 'Residential', which it worked until it's withdrawal in 1957 following a 'heavy contact' with the buffers at Porthcawl.  The 'Residential' had been handled pre-war by a succession of Bulldogs, not the usual fayre for a South Wales coalfield shed, but Tondu had 44xx as well!  And banging on about my wishlist items works for me with Dapol, as they have relented and put the ex-Lionheart Diagram N autotrailer through the 4mm ray after me reminding them every so often over the last eight years or so...

 

3100 was the doyen of a class of five, and was rebuilt from a 3150.  The difference was a 220psi boiler and 5'3" drivers, which will be even more of a drop in size than between a 61xx/5101 and a 81xx and again require an new body tooling.

 

The problem with GW engines is that they are all the same except when they are different, and they are in fact all different in subtle and devious ways.  When you get used to them you can identify the difference between a Grange and a Hall front-on from about half a mile away; the sit is different, it's only 2" but it is discernable.  Boiler pitch is determined by wheel diameter, so for a no.4 the highest were the City/Atbaras and Churchward Counties, and the lowest the Aberdares and 8-coupled tanks.  3150s were the same in that respect as the 43xx moguls, but the moguls had a longer low section of running plate ahead of the smokebox saddle, so the proportions were different, a mistake I made during my ongoing and occasional attempts to kitbash 3100 out of RTR bits from an Airfix 61xx and Mainline 43xx and 56xx bodyshells.

Your maths are out here! There isn't a 2mm difference in wheel size,it's 2" on the prototype which is 0.66mm on the model,well within 'worn tolerance limits' should they decide to go that way,although that does depend on what diameter the Dapol 5'8" wheels are in model form If they are oversize they'll be no good for an 81XX, if they are slightly undersize,they may get away with it!

[The Stationmaster]

On 10/08/2023 at 17:13, Miss Prism said:

 

I think it probably is ex-works, but I question the date given - red background plates had long ceased on new paintjobs by 1955. Front number plate has gone walkies it would seem. Or, the date is more like 1949/50, with the loco first appearing in a non-GWR scheme and awaiting delivery of the smokebox number plate. I will amend the gwr.org.uk caption to be less certain! One thing is for certain though - the plates are red background. It's not a good photo, shed plate detail is indiscernible.

 

Are we sure that it is 8104?  We can't read the numberplate or the shed plate so we haven't got much to go on however 8104 was. a Court Sart engine at that time and that definitely isn't Court Sart shed.  

 

There is apublished ohoto of 8104 with what appears to be a light colour to the background of the numberplate and that is dated 1958, one unusual feature of the engine that shows in that photo was the unusual position of the RA disc.  and dn't forget that some sheds painted number plates at times just to add confusion.

 

The other interesting thing about the photo is its location, which despite the rofusion of brick buily t chimneys I'm having considerable difficulty in pinning down,

[Miss Prism]

22 minutes ago, The Stationmaster said:

Are we sure that it is 8104?

 

Judge for yourselves:

 

https://www.alamy.com/great-western-railway-gwr-5100-class-known-as-the-3100-class-between-1912-and-1927-2-6-2t-prairie-tank-steam-locomotive-no8104-seen-at-swindon-works-in-about-1956-image510193279.html?imageid=4449DAE1-B3EF-44C0-9CF7-26CD75853176&p=149870&pn=1&searchId=37ccbb52402a8bd856975029510cfe96&searchtype=0

 

[1466]

4 hours ago, jamieb said:

Your maths are out here! There isn't a 2mm difference in wheel size,it's 2" on the prototype which is 0.66mm on the model,well within 'worn tolerance limits' should they decide to go that way,although that does depend on what diameter the Dapol 5'8" wheels are in model form If they are oversize they'll be no good for an 81XX, if they are slightly undersize,they may get away with it!

40 odd years ago I bought a couple of the then new Airfix large prairies and converted them to EM gauge with beautiful Ultrascale wheels . It later occurred to me that I had sufficient drivers to make an approximation to an 81xx class using the Airfix undersized drivers . As my models were from the first production run , I was able to swop flanged drivers with the centre flangeless ones  .

The 81xx wasn’t a great success. I seem to recall I used 1:8th inch  steel rod axles and the wrong shade of green . It never ran well and is stored somewhere .

About 10 years ago I picked up another Airfix prairie with the intention of using it ( a better runner) to make another 81xx . Still not got round to it .

[melmerby]

7 hours ago, Miss Prism said:

 

Judge for yourselves:

 

https://www.alamy.com/great-western-railway-gwr-5100-class-known-as-the-3100-class-between-1912-and-1927-2-6-2t-prairie-tank-steam-locomotive-no8104-seen-at-swindon-works-in-about-1956-image510193279.html?imageid=4449DAE1-B3EF-44C0-9CF7-26CD75853176&p=149870&pn=1&searchId=37ccbb52402a8bd856975029510cfe96&searchtype=0

 

Looks like it's standing in front of the original straight road shed (off picture to the left) with the rooves of the 1908 turntable behind.

The breakdown train will be standing in the spur which comes off the easternmost straight road shed track

Edited August 12, 2023 by melmerby

[Hilux5972]

On 11/08/2023 at 02:18, Ian Hargrave said:

Thanks Robin. Will this iteration correct the design defect in the bunker axle spring that caused loss of contact resulting in erratic running over point work I wonder ?

The announcement does say modification’s to the rear pony truck 

[The Stationmaster]

21 hours ago, Miss Prism said:

 

Judge for yourselves:

 

https://www.alamy.com/great-western-railway-gwr-5100-class-known-as-the-3100-class-between-1912-and-1927-2-6-2t-prairie-tank-steam-locomotive-no8104-seen-at-swindon-works-in-about-1956-image510193279.html?imageid=4449DAE1-B3EF-44C0-9CF7-26CD75853176&p=149870&pn=1&searchId=37ccbb52402a8bd856975029510cfe96&searchtype=0

 

Right so definitely 8104 as the numberplate is fairly clear.   Defiinitely not Swindon Works but almost certainly Swindon Shed and the breakdown van gives a good clue to where it was standing (see also Melmerby's post above).

 

I think the suggested 1956 date is probably inaccurate.  There is solid evidence (an Eric Mountford photo) that Caerphilly were painting number plates on small tank engines black in 1956.  There is equally evidence from an earlier, undated, H C Casserley photo that Caerphilly had at one time been painting number plates red on such engines and the example I have found (ex RR Class P, No 83) was withdrawn in 1955 so was unlikely to have been given a major overhaul and repaint any later than 1953.  So I think the photo definitely predates 1956, possibly be several years