GWR 31XX or 3150 from SEF parts

[Weaselfish]

Good evening.

 

Has anybody tried using the Wills/South Eastern Finecast GWR County boiler and 61XX kit to produce a 31XX or 3150 2-6-2? There's a nice one here http://www.crphillips-models.co.uk/gwrmodelspage15.html which uses a Nu-Cast City boiler but there's not many of those about now. The revived thread here http://www.rmweb.co.uk/community/index.php?/forum/167-gwr-rolling-stock-model-and-prototype/ discusses various boiler swaps and prompted me to ask.  

[Il Grifone]

It should work. I haven't used the SEF parts but I did a 3150 a long time ago using Kitmaster/Airfix parts. The difference in boiler diameter is almost invisible thanks to the tanks.

 

One day I intend to do it again properly (famous last words). I had the plates for 3104 once, but I think they have been lost over the years.

[Horsetan]

Remember the cab is markedly different - more akin to the shape on a 42xx or even a 56xx.

[Clearwater]

What's particularly interesting on the Phillips' site is the number of kits, particularly from the pre-collett era that have been lost or are out of production. I'm thinking particularly some of the precursors to the 45xx tanks. Other than the sefinecast Saint, there isn't another saint I can find on the market particularly with the straight running plate.

 

David

[Coach bogie]

The bunker has variations as well. David Geen is working on a kit for the 3150. As part of the research/design tech a Wills 61XX and Nucast 52XX and Wills County castings were cut and shut. The rear end has more in common with a 52XX than any of the Prairies.

 

Mike Wiltshire

[Weaselfish]

The bunker has variations as well. David Geen is working on a kit for the 3150. As part of the research/design tech a Wills 61XX and Nucast 52XX and Wills County castings were cut and shut. The rear end has more in common with a 52XX than any of the Prairies.

 

Mike Wiltshire

Thanks all. I hadn't noticed that there was such a difference at the cab end. It's not mentioned in the RCTS volume or in the Russell book but comparing photos of 5101s and 31xxs does make the difference clear.

 

MIKE: Do you know when the David Geen kit is likely to be on sale and if it will offer the curved drop end variant?

 

Thank you,

 

Mark

[Coach bogie]

Thanks all. I hadn't noticed that there was such a difference at the cab end. It's not mentioned in the RCTS volume or in the Russell book but comparing photos of 5101s and 31xxs does make the difference clear.

 

MIKE: Do you know when the David Geen kit is likely to be on sale and if it will offer the curved drop end variant?

 

Thank you,

 

Mark

 Just spoken to the man. Still in development, hope to be out next year. Intention is to produce etched chassis based a simplified Mitchell mogul frames with a mix of etched and cast body parts. Straight frame to come out first.

 

Mike Wiltshire

[Weaselfish]

Thanks Mike. That sounds good. I'll await developments with interest.

 

Mark

[DCB]

The 3150 has got a very different look to the 61XX and derivatives.     The 61XX was designed for the metropolitan widened lines with a lower steel cab roof and most if not all the small boiler large prairies were altered to match losing the high arch canvas and wood high cab in favour of a lower steel sheet along with the change in weight distribution and renumbering from 31XX to 5101 series  

 

The 3150's  big smokebox and squat smokebox saddle and full height cab roof are more like a 42XX .  However the 42/52/72XX kits are pretty bad, e but I guess you could make a reasonable late 30s on curved frame 3150 from a Wills 61XX with Ks 42XX boiler top and Cab roof.

 

The straight frame one would be awkward, as would the pre bunker extension version.

 

The 1938 ish 31XX  small wheels etc is more awkward with its strange reshaped cab, but they did not seem to be very successful locos, I think the 3150s were very sure footed with relatively low tractive effort while the 31XX were more powerful but prone to slipping which is what you don't want in a purpose built banker.  I believe they finished their days as very successful suburban passenger locos with exceptional acceleration, rather like what the LNERs L1s could have been if only they had had reliable inside Stephenson valve gear instead of the strange Belgian stuff like the 102 class and Vale of Rheidol 2-6-2T used.

 

I did wonder about Dapol or Airfix/Hornby 61XX tanks and bunker on a Bachmann 93XX to make a 3150 as the Bachmann has a decent chassis and the Airfix/Hornby 61XX does not.   In fact I wondered about re engining the Hornby 61XX with a Bachmann chassis to make a decent 41/51/61XX.

 

I'm half way through fitting a Wills Hall smokebox and part of the boiler to a Grafar 81XX to create a 3150, might graft on a GEM 56XX cab roof  or I'll have to make a brass one.  Currently I use a Triang Hall chassied Grafar 81XX and Wills 61XX and as bankers as two Hornby 61XX don't run well enough for the task despite being bought to replace the poorly detailed Grafar and now rather tired Wills 

Edited November 10, 2016 by DavidCBroad

[Edwardian]

 Just spoken to the man. Still in development, hope to be out next year. Intention is to produce etched chassis based a simplified Mitchell mogul frames with a mix of etched and cast body parts. Straight frame to come out first.

 

Mike Wiltshire

 

There are, for certain projects, certain locomotives that are 'must-haves'.  Despite my lack of budget or skill to take on any but the simplest loco kit, at present anyway, this is a kit I would have to acquire, and more than one.  For a layout set between the South Devon banks in the 1930s, 3150s are essential.  

[The Johnster]

On 10/11/2016 at 06:02, DCB said:

 

The 1938 ish 31XX  small wheels etc is more awkward with its strange reshaped cab, but they did not seem to be very successful locos,

Thread bump alert...

 

I'm not sure I agree with this; apparently Collett intended to convert all the 3150s to the 1938 31xx specification, but the war put a stop to the idea and Hawksworth wasn't interested, so the bulk of the 3150s survived unrebuilt until withdrawal, and the 1938 31xx, with components the same age, were withdrawn around the same time.  There was some sort of accounting jiggerypokery involved with the late Collett rebuilds of large prairies, both these and 81xx. 

 

3100 was allox Tondu in 1946 for the post-war re-introduction of the daily Porthcawl-Cardiff commuter service, the 'residential', hauled in prewar days by a series of Bulldogs.  This train loaded to 5 bogies and the loco was used because of it's ability to accellerate rapidly from the main line stations served by this train, enabling it to be sharply timed and kept out of the way of faster traffic on the busy SWML between Pyle and Cardiff.  It performed this duty until 1957, when it was apparently involved in a 'heavy contact' with the stop block at Porthcawl and sustained damage to the frame (see John Hodge/Stuart Davies Tondu Valleys books). 

 

It was sent to Swindon for assessment, and as the 3150s were being taken out of service by then, not considered worth repairing and withdrawn, it's 4 sisters joining it over the next 3 years.  But it was well liked and considered ideal for it's task at Tondu, better than it's replacement, 4144.  Photographs of it at Swindon after withdrawal do not show any obvious signs of deformation of the frame or running plate.

[The Johnster]

On 30/10/2016 at 09:00, Il Grifone said:

The difference in boiler diameter is almost invisible thanks to the tanks.

 

I don't agree; the larger boiler is a very prominent feature of the 3150s and even more so on the 1938 Collett 31xx.  The tanks hide the difference for that part of the boiler that they conceal, but the smokebox, the 'face' of the loco, is noticeably bigger, and because it sits to the same centre line as the no.2 boiler on the Churchward 31xx, and Collett 61xx and 5101s, the bottom edge of it is closer to the running plate; the outside steam pipes are shorter as well.

[The Stationmaster]

On 10/11/2016 at 06:02, DCB said:

The 3150 has got a very different look to the 61XX and derivatives.     The 61XX was designed for the metropolitan widened lines with a lower steel cab roof and most if not all the small boiler large prairies were altered to match losing the high arch canvas and wood high cab in favour of a lower steel sheet along with the change in weight distribution and renumbering from 31XX to 5101 series  

 

 

The 61XX was not designed for the Widened Lines - fairly obviously the case when you look at it because they never had condensing gear (which was a requirement for any steam engine working over the Widened Lines from the Paddington end).  The cab roof line and construction matched that of the 5101 class which had appeared two years before the first 61XX emerged from Swindon.

[DCB]

The 61XX worked over electrified lines at Paddington and had Metropolitan trip cock gear and a clip up ATC shoe  to allow this, I believe only the 97XX of the other Collett era designs shared this.    I read the lower cab roof was to allow use over Metropolitan lines, but my post was in 2016 and I can't remember where  read it. However it seems the 3110 /5110 roofs were changed from wood and canvas to steel from 1921 on and there seem to be pictures of the older 5110 series locos with the lower roof prior to the 5101 being built, though the dates maybe wrong.  The thing I cant discover is were the cab roof profiles / styles changed when the steel sheets were added or was it a two stage process, bearing in mind they were shopped at 75K miles or approx 18 month intervals.

[The Stationmaster]

2 hours ago, DCB said:

The 61XX worked over electrified lines at Paddington and had Metropolitan trip cock gear and a clip up ATC shoe  to allow this, I believe only the 97XX of the other Collett era designs shared this.    I read the lower cab roof was to allow use over Metropolitan lines, but my post was in 2016 and I can't remember where  read it. However it seems the 3110 /5110 roofs were changed from wood and canvas to steel from 1921 on and there seem to be pictures of the older 5110 series locos with the lower roof prior to the 5101 being built, though the dates maybe wrong.  The thing I cant discover is were the cab roof profiles / styles changed when the steel sheets were added or was it a two stage process, bearing in mind they were shopped at 75K miles or approx 18 month intervals.

To get it right - when built the 61XX worked into Bishops Road  station (later to become Paddington Suburban)  over the Hammersmith & City Line from the junction at the west end of Royal Oak station which was jointly owned by the GWR and the Metropolitan Rlwy.  That line was electrified and passenger trains for to/Liverpool Street changed engines at Bishops Road being worked between Bishops Road and Liverpool Street by Met electric locos.   Accordingly the 61XX had clip-up ATC  shoes and trip cocks inorder to operate between Royal Oak and Bishops Road (the Pressed Steel DMUs which succeeded them were similarly equipped in order to work in and out of Paddington Suburban).

 

The 97Xx were different in that they needed to work over tunnelled sections on LPTB lines (the Metropolitan and Circle Lines) in order to access the Widened Lines at Farringdon get to/from Smithfield GWR freight depot and therefore had to have condensing gear (which they were supposed to use) as well as trip cocks although interestingly the trip cocks were only positively required to be operational between Paddington Suburban (not Royal Oak)

and Aldersgate.

[Coach bogie]

I made mine from Cotswold/Nucast 52/72xx set of castings on a spare mogul chassis. On the plan the Costwold parts were more suitable and it does have the correct boiler. It also provides the square front end for the earlier version.

 

Mike Wiltshire

 

[Miss Prism]

On 16/09/2021 at 12:48, DCB said:

The thing I cant discover is were the cab roof profiles / styles changed when the steel sheets were added or was it a two stage process, bearing in mind they were shopped at 75K miles or approx 18 month intervals.

 

I think it was definitely a two-stage process for the 3111/5100 classes, with steel roofs being fitted from 1921 (as you note) keeping the original high roof profile, i.e.. like this, and the lower roof, i.e. like this, was apparently fitted to most of the class between 1931 and 1939. It may even have been a three-stage process if you count the blanking off of the cabfront portholes. I don't know why the lower roofs were fitted - I'm not aware of any loading gauge issues. Or maybe it was easier to use standard Collett-shaped parts?

 

[JimC]

On 24/09/2021 at 13:03, Miss Prism said:

 I don't know why the lower roofs were fitted - I'm not aware of any loading gauge issues. 

 

The GWR standard loading gauge changed from 13'2" to 13'6" height in the centre about 1908. I imagine it took some time for that to be universal round the majority of routes, and some branch lines never even made the 13'2 figure. By and large the extra height was only made use of for 4-6-0s, 2-8-0s and the like, with most other classes staying pretty much within the old limit. However going through Russell I see cab roofs on 2221 and 31/5111 in their original form were fractions of an inch over 13'2, as is diagram A13 for the new 3100s. The 5101s, 6100s and 8100s OTOH were a good deal lower, under 12'8 as were the 5111s in their final diagram. Below 13' is within reach of the vast majority of the pre group gauges, whilst the Met widened lines were 12'8".

[Miss Prism]

Thanks Jim. Must admit I had always thought the height had been standardised (at 13'6") since the dawn of time.

 

Were the Churchward Counties (of 1904) in breach, or am I looking at the wrong diagram?

 

Also, the steam railmotors (of 1903) were 13'6", so I suspect most of the system was actually happy with that dimension.

 

It would however explain contemporary pictures of the 'gauging vehicle' (a converted Toad iirc).

 

 

 

 

Edited September 26, 2021 by Miss Prism

[JimC]

I'm not sure. The story seems complicated. I've got an 1899 gauge diagram which is 13'3, and a mention of a new gauge in 1908 in the GWR magazine. There's also a drawing in the NRM archive of a proposed gauge made a few years later which I haven't seen. It needs more detailed research than I've been able to do from my desk I suspect.

[melmerby]

This  gives some comparisons, I don't know the efficacy of it.

13' 6" seems to be fairly common around the UK

 

 

 

 

Edited September 26, 2021 by melmerby

[The Johnster]

There was certainly an inconsistency in cab roof shapes for large prairies, and I believe the Collett 31xx, last in the line of development, took advantage of the lower running plate to use an even more pronounced curve to the roof than the 3150s it was rebuilt from, and is similar to the 42xx/5202/72xx classes and the 56xx.  Mine has a 56xx cab roof and spectacle/rear cab bulkhead plate, and looks 'about right', or at least 'about right for a kitbash...'.

[JimC]

1 minute ago, The Johnster said:

 similar to the 42xx/5202/72xx classes and the 56xx.  Mine has a 56xx cab roof and spectacle/rear cab bulkhead plate, and looks 'about right', or at least 'about right for a kitbash...'.

The smaller wheeled classes tended to be a tad lower on the whole, unsurprising I suppose. I've just been through Russell starting to compile a table of cab heights, but by the time I got half way through looking at the drawings of locomotives against loading gauge it became evident that more often the cab roof eaves are closer to the limits of the GWR gauge than the centre of the roof, so the centre value was of dubious usefulness and I stopped. No doubt 56s and 42s also had to take into consideration the various loading gauges on the absorbed lines.

[The Johnster]

Churchwardian locomotives with 2 outside cylinders use the standard Churchward construction of a cylinder and half (smokebox) saddle bolted together, which is I believe based on American practice.  So, a locomotive with 5'8" driving wheels such as a Churchward 31xx, or Collett 5101 or 61xx,'sits' higher at the running plate and boiler centre line than an 81xx with 5'6" wheels, though in this case the difference is slight and will overlap with the normal wear limits of the tyres.  I am not sure how this affects the cab roof profile, which is I think the same between 5101, 61xx, and 81xx. 

 

But when one compares the Churchward 3150, 5'8" wheels and a no.4 boiler which sits a little higher than the no.2 on the 31xx, 5101, and 61xx because it is larger (yet has a more pronounced curve to the roof than the later steel roofs on the 5101, 61xx, and 81xx), to the Collett 1938 31xx, a rebuild of the 3150 with 5'3" driving wheels, the difference is more noticeable; the running plate and boiler centre line are now dropped 2 and half inches.  The Collett 31xx has an odd cab side profile, in which the original side sheets are apparently re-used but there is a filled in piece between the top of the cab cutout and the edge of the roof.  With the smaller diameter driving wheels, the size of the boiler and the height of the cab make the loco look even more powerful  and impressive.

 

The 42xx, 5202, and 72xx classes also feature no.4 boilers, but with 4'7" driving wheels, and much lower running plates.  The boilers therefore sit even lower between the tanks, which are bigger than on the prairies because they are 'extended' down to the level of the lower running plate.  On the 56xx, a no.2 boiler is used with similar side tanks.  On all these locos quite high cab roofs feature, with a smaller radius curve to the roof than on the Churchward 31xx, 5101, 61xx or 81xx.  The actual shape and contour of the cabs and the cab roofs are bespoke to each design; all GWR locos are the same except for when they are different!

 

So, you can't make a Collett 31xx out of a 43xx boiler set into the tanks and running plate of an Airfix 61xx, you have to drop the running plate by just under a millimetre as well.  Some of this drop will occur automatically when you replace the driving wheels with 21mm Markits, and on my project I've opted to go for 20mm, within the wear range of the tyres, but you still have to make a horizontal cut just beneath the front of the main section of the running plate where it drops to the lower level in front of the smokebox.  There is also a small section of splasher at the front of the tanks which is too large for the 31xx, but I'm going to live with that as it is obscured by the motion bracket and lubricators and not prominent.