Taff Vale Railway O3 class 0-6-2T

[RosiesBoss]

Introduction

 

My “Carmarthen Junction” loco collection has at least two main streams: Mid-Wales and South Wales. Of late, I have been adding to the former group, with the latest being 0-6-0 No 885. http://www.rmweb.co.uk/community/index.php?/topic/88895-gwr-ex-cambrian-railways-73-class-0-6-0/

 

My South Wales area locos include 2161, 1670, 6667, 2620, 2818, 3020 and possibly 2783. For several years, I had been trying to add another absorbed 0-6-2T to this group, in the form of a Wills Finecast U1 class loco. I acquired just such a model at the Epping Model Railway Club show in July 2014 as a partially assembled example, with a motorless Hornby Dublo 0-6-0 chassis (which is listed as a suitable chassis for the kit).

 

What a disappointment! On comparison with the drawings of the U and U1 class locos in Russell, I realised that the wheelbase of the Dublo chassis was far from correct:

U and U1 Class: 7’5”+7’0”+5’10”

Dublo:  6’6”+8’0”

 

 

The driving wheels on U and U1 classes were of 5’3” dia; the Dublo model has 5’0”drivers.

 

Packed with the model was a pony truck with 14 mm (ie 3’6”) dia wheels, held onto the chassis with Blu Tac(!). The corresponding wheels on the U and U1 locos were 3’8.25” and 3’1” respectively.

 

There were just too many compromises for me to use the Dublo chassis, so I looked through my scrapbox and found a cast whitemetal chassis, complete with motor, 14mm dia driving wheels and gears that I had bought “on spec” a few months earlier at the Richmond Vale Railway Museum model railway show. This has the correct axle spacing, but I had to change the Romford wheels for similar larger ones.

Comparison of my “bits” with the drawings of several TVR locos in Russell, I realised that the best match was with the O3 class 0-6-2T, which had a very similar body to that of the model and wheel spacing 7’5”+6’0”+5’10” (the same as the motorised whitemetal chassis). Driving wheels were 4’6” and trailing wheels 3’1”. I had 18mm dia driving wheels and 12mm dia trailing wheels in my scrapbox, so this made it a practical way forward.

 

Prototype Notes

 

 

Fifteen  O3 class locos were built, in three batches  between 1902 and 1904 by Hudswell Clarke & Co.,  Kitson & Co. and Vulcan Foundry for the TVR. All passed into the GWR at grouping. Most were rebuilt or modified by the GWR. Withdrawal and scrapping was prolonged – between 1928 and 1948. None were preserved. Photographs of the class are not common, but those that are extant reveal many variations between individual locos, including cab height, chimneys and bunkers. They are challenging to model accurately.

 

I’ve chosen to model No 411, one of the last survivors, but in the condition she was in in the early 1930s, before her bunker was rebuilt to standard GWR form.

 

Donor Models

• Wills Finecast U1 class body kit, as received - partly assembled

 

• Second-hand whitemetal chassis, motorised

 

• Wheels and crankpins from scrapbox

 

Construction

 

I began with the chassis, replacing the 14mm dia wheels with 18mm dia ones. These were fitted with Romford crankpins and the original coupling rods. This assembly was tested under power to verify that there was no stiffness in the mechanism.

 

 

I fabricated an extension to the rear of the chassis from 0.5” x 0.5” square section channel brass, trimming it until it was a neat fit into the rear of the body.

 

I slotted this piece to accept 12mm dia wheels on a 2mm dia axle and then fabricated a simple axle mount from brass tube, an 8BA bolt and an spring from an ERG 3-link coupling. This assembly was then installed in a hole drilled through the top of the channel and secured with 8BA locknuts until it provided just the right amount of vertical play.

 

 

The original pickups were adjusted and the running chassis was tested under power on my layout, through points and around curves in both directions to check that it was not too rigid. It worked well with minimal adjustment needed. Testing was repeated with the unaltered body fitted to the chassis. Again, there were no problems. I did observe that, with a kind of radial rear axle, its appearance when running was superior to that of my model of 1670, which was constructed with a non-prototypical rear pony truck.

 

 

Slim tension-lock couplings were fitted front and rear.

 

A simple backhead was prepared from a Hornby spare, but not fitted until the inside of the cab had been painted.

 

 

A false floor was then fabricated from polystyrene sheet and attached to the frame.

 

The chassis was further improved by fabricating guardirons from brass and gluing those to the front and rear.

 

 

I now turned my attention to improving the body, with particular attention to:

• Safety valve & whistles
• Handrails
• Lamp brackets
• Steam pipe from cab to smokebox
• Scale (dummy) couplings

Photographs of O3s in service show a GWR safety valve cover that is much slimmer than that provided in the Wills kit (and installed previously on this example). I chose to replace this with one sold as a spare for the Tri-ang/Hornby Dean Single, together with turned brass GWR whistles recovered from the same damaged Thomas body that donated its face to Henry: http://www.rmweb.co.uk/community/index.php?/topic/86971-henry-comes-to-carmarthen-junction/.

 

Handrails were made from turned brass handrail knobs and brass or phosphor bronze wire and installed into the holes inherited from the body’s previous owner.

 

Lamp brackets were made from domestic staple wire, as in other projects.

 

Photos of O3s show a steam pipe running from cab to smokebox.  Some had the pipe on the left side; others had it on the right side. Preserved TVR No 85 has it on the right side, but preserved TVR No 28 does not have such a pipe. Figure 304 in Russell showing GWR 411 in 1937 shows this pipe on the loco’s left side, so this is where I have modelled it.

 

The model now was ready to paint:

 

 

 

Once all details were in place, I painted the chassis and body with Humbrol enamels, installed the backhead and applied HMRS “Pressfix” transfers and home-printed numberplates. I then gave the body a fresh coat of Humbrol satin clear.

 

 

 

Reflections

 

Compared with many previous projects, this one has been fairly straightforward. The main challenges have been to determine what details to add to the basic Wills kit body, as the sketch in Russell is very basic and detailed photographs of O3s in GWR service are not common.

 

The final result is not of “museum quality”, but the model does look well with a string of PO wagons and ex-TVR “Toad” 68912 bringing up the rear. It certainly looks different from models of U1 class fitted onto Dublo chassis.

 

Here she is again, hauling PO empties past my other two 0-6-2s, 6667 and 1670:

 

 

References

1. RCTS “The Locomotives of the Great Western Railway – Part 10 – Absorbed Engines1922-1947 (RCTS, 1966)
2. J.H.Russell: “A Pictorial Record of Great Western Absorbed Engines” (OPC, 1978)

[Darwinian]

That's really neat, well done.

I've often looked at the U1 and wondered if something a bit longer lived could be made of it.

 

Will have to see if I can do something similar at some point. Too many other projects on teh go at the moment.

 

Adrian

[Penrhos1920]

The old Wills U1 kit is very versitile.  There is a very good exhibition layout with many U1 kits all built as different Taff Vale prototypes.  All you need is the book GWR Absorbed Engines. 

 

I thought that the O1 to O4 classes were shorter than the U1?  I think I remember cutting out a section of boiler and sidetanks when I made my model of an O2, number 85.

[RosiesBoss]

G'day all and thanks for the comments and "Likes".

 

The O3 boilers, as shown in Figure 306 of Russell are a little shorter overall than the U1 as modelled by Wills. However, the modified version shown in Figure 307 is a close match.

 

In my case, I started the project with a bare, assembled body, which I aimed to use with minimal structural changes.If I had started with an unassembled kit, I may have shortened the boiler. I was much more concerned with getting the spacing pattern of the wheelsets to conform with the prototypes, as the Dublo chassis just did not look right.

 

The model "ain't perfect", but it does look right when running with a long string of PO wagons.

 

This model was never built to look pretty on a shelf behind glass, but has to work for its existence!

 

Regards,

 

Rob

[LaScala]

Here's a near relative 04 snapped by my Dad in 1939 on the scrap line at Swindon if it's of any interest..

[tomparryharry]

The U1 model is a near close cousin of the earlier O classes. I've got a few here. One is nearly finished, but I'm frightened to paint it!

 

Taff Vale 28 had it's vacuum ejector on the right side. All of the evidence, such as frame cut outs, puts it over there. The NCB removed the vacuum brake, so no ejector pipe at the moment.

 

For my models, I've used a much modified Will/SEF 61xx chassis, which is turned backwards. It gets the motor out of the cab, and the driver spacing is quite good. Like you, I've made up frame extensions, as the original locomotives didn't have a pony truck.

 

The late Eric Mountford told me that the 'Western' didn't repaint second rank absorbed locomotives green. They generally went, or stayed black. A major rebuild, such as the A class, resulted in a repaint to green.

 

Dave Ellis at SEF has mentioned in the past that he might well upgrade the U1. I can't wait. However, if he re-issues the Cotswold A class, who am I to argue? One can but dream....

 

Ian