GBL BoB - Part 8

The choice of name for my BR(S) Bulleid West Country pacific conversion from the GBL BoB posed no problem at all. Those who follow this Blog or visit my model railway website will know my layout is based on Crewkerne in Somerset. Since my track plan is much simpler than early 1960s Crewkerne I named the station after the nearby village of Misterton, which is in fact closer to the station than the town! In homage to the real station it is fitting to name the model locomotive after it - Crewkerne.

The full size locomotive was built at Brighton works, entering service in September 1946 as 21C140 and named Crewkerne in October 1948. It was rebuilt (air smooth casing removed etc.) in October 1960 at which point the tender was changed to the low sided variant. In original configuration it was first allocated to Stewarts Lane shed for south eastern routes and then transferred to Bournemouth shed for Waterloo to central southern England services. It also hauled the Pines Express over the Somerset & Dorset Joint Railway. I am doubtful it was used on BR(S) south west routes although it has been reported hauling the Plymouth to Brighton train in 1949. Whether it ventured into the south west or took over this train at Salisbury I do not know. Nevertheless, it operates on my layout through Crewkerne a.k.a. Misterton in the summer of 1960 shortly before it went for rebuild.

On the model the lining, side panel numbers and BR crest are from HMRS Pressfix transfer sheets. The Crewkerne and West Country Class banners, shield and smoke box door number were designed in a graphic editing Application using a resolution of 600 pixels and printed on sticky label. The final addition to the model was a Hornby speedometer cable, which required a plasticard pocket to be made for holding the cable bracket tab behind the side panel.

I said to myself several times that it is finished and then found something that needed doing. More detailing and GBL design corrections could be carried out but I think this will do nicely. It sits well alongside my super detailed Hornby locomotives and is far superior to my Airfix/Kemilway BoB model that I built over 30 years ago.

Purchased 'super detailing' parts amounted to £14.45 bringing the total cost to £61.43 plus bits from my spares box and some DIY 3D printed components.

To Part 1.

GBL BoB - Part 7

More detailing described in this post.

Up first is the safety valves, a significant and noticeable part of the roof but sadly missing completely from the GBL model and presumably the Hornby variant that it was copied from.

The safety valves and surrounding housing is a white metal casting from Regent III of Coventry. Bought it from a trader at Andover Modelex. I can't find Regent III on the web but RT Models have the exact same part. All I needed to do was accurately cut a rectangular hole in the roof to accept the implant. I also took the opportunity to beef up the T shaped whistle with plastic card. It was just a whisker on the GBL model. I had a look at the roof of 34007 Wadebridge in a video and noted these parts were black with grime instead of shiny brass so I have coloured likewise.

Moving down the loco the next photo shows fitted loco crew (Langley models) and window glass. The latter cut from transparent plastic packaging.

Next we have the head code disks for the Waterloo -Exeter route.

Finally, below deck, are the cylinder drain pipes. These are made from copper wire and butt glued to the cylinders. I think this is a bit too fragile and when they break off I'll remake them and drill some holes in the cylinders for insertion. That will be stronger. The pipes stick out sideways more than they should to allow the bogie to negotiate model track curves without interference.

To Part 8.

To Part 1.

GBL BoB - Part 6

I fell headlong into the Brunswich Green trap for a BR(S) period livery.

The GBL BoB lining, number, nameplate and shield were removed by rubbing white toothpaste over them with an old tooth brush. This was a tip from RMWEB which recommended toothpaste as it does not have a chemical composition that could damage the underlying plastic. The toothpaste is effective but also removed the paint finish revealing the black plastic beneath, which was unaffected showing no scratch marks from the rubbing.

The body work was sprayed with Halfords grey primer and then Brunswich Green (Humbrol #3) after which I thought the green looked too bright compared to photographs of the prototype. (I know paint matching to photos is a big no, no). I started to research further and found that Brunswich Green is a misnomer for what should be called BR(S) Dark Green. A couple of model paint manufacturers supply the 'correct' green but I was not sure these were definitive for BR(S) locomotives of the late 1950s early 1960s. Furthermore, some commentators recommend a lighter shade than the correct green because of the effect of light diffusion on normal model viewing distances of 25 - 75 yards in 4mm scale. I looked at my loco stock from Hornby, G.R. Wren and Mainline and they all had different shades of green for the same period and even different shades across Hornby locomotive classes! I realised I had entered the minefield of paint matching. I decided to mix my own paint to achieve a shade somewhere between the dark Hornby green and lighter Wren green. The Mainline colour was far too light.

My mix was made from what I had available, Humbrol brunswich green 3 (gloss), green 30 (matt) and gloss black Interestingly, the mixing of gloss and matt gives a silk finish like the finish of proprietary models.

The first spraying looked OK in natural light but appeared too light in artificial light and of course whilst still wet is darker than when dry. Very difficult to get right but further refinement of the mix gave a finish that fared better in natural and artificial light and sat well between the Hornby and Wren paint finishes. However, in full sun it takes on a lighter shade! (I'll live with that). I can't give the paint proportions as it was trial and error.

Some detailing has been added. The pipework below the cab was made from soldered copper wire and replaced the GBL modelled pipework, which was totally incorrect for this side of the cab in the photo. Vacuum pipes, steps and screwlink coupling added to front buffer beam.

More to do - details and lining etc.

To Part 7

To Part 1

GBL BoB - Part 5

I spent ages comparing the buffer beam position and size against a scale drawing of the locomotive trying to decide where the main error was, what to fabricate and where to make the cut.The dimensional errors are the valance height, buffer beam height and the height of the vertical panel above the buffer beam. All need their height increasing to match the scale drawing.

Of particular concern was the valance above the front bogie that curves around the front because cutting into that and fabricating a replacement could be tricky. I noticed from prototype photographs that some locomotives in the class do not have a valance. I then checked out the actual engine that I am modelling (to be revealed later) and found it belonged to be one of these. This makes the modification much easier. It was a simple case of a straight cut with a razor saw to remove the valances and offending buffer beam parts.

The replacement buffer beam was designed and 3D printed in three parts that were then cyanoacrylate glued together and to the body. It is difficult to show the detail because the white plastic tended to bloom in the photo. I have played about with it in a photo editing application to try and reveal the detail. Trust me, it looks better than seen in the photo.

The circular Southern ring on the front of the smoke box door was very carefully dremelled away with the grinder attachment so that just a small remnant remained. This was scrapped away with a scalpel, which leaves a more shiny surface that the dremel does. Finally, this area was polished with the dremel polishing pad attachment.

The white areas are to be painted.

Finally, I was pleasantly surprised to see that a Zero 1 chip can be located within the body without interference or modifications. It is stuck with double sided tape on top of the chassis weight.

To Part 6.

To Part 1.

GBL BoB - Part 4

Here is the 'Great British Locomotives' Battle of Britain body fitted to a Hornby motorised chassis.

And this is how it was done.

1. Coupling Peg

The coupling peg from the GBL pony truck was cut off and glued to the tender coupling and excess removed so that the tender and locomotive coupled closely ensuring it still went around curved track without hindrance.

Getting the peg to mate with the loco chassis was troublesome because the chassis part has springy electrical pick-ups that tend to push the lightweight tender upwards off the track. I did not want to cut off the pick-ups, even though they are not used in this implementation, because I wanted to keep the chassis intact as possible in case it is redeployed in the future. So, by a combination of spacing off the chassis coupling by about 2 mm and thinning the peg flange an acceptable fit was achieved.

2. Chassis Modification

The width of the body is narrower than the cylinder block on the chassis, which needs to slide/locate inside the body by a few millimetres. I had to grind back the cylinder block and relieve a bit of the central protrusions to achieve the fit. I don't think this upsets the fit of a genuine Hornby body if it was decided to fit one later.

3. Body Hacking

That red slide bar bracket also locates inside the body. It is not practical to cut it back to fit so, the body sides were thinned to 50% of their thickness in the area of the cylinder block and slide bar bracket.

Further relief was created as shown in the photo to accommodate other parts of the chassis and a new chassis screw fixing block fitted. Whilst cutting out the internal ribs the Dremel sliced through the body at the roof line leaving a slot a few millimetre long! This was filled with a slither of plastic card, which can just be seen in the photo top of this posting. Once painted it will be fine.

At the other end of the locomotive GBL had made provision for the Hornby chassis locating lugs. But, either the body overall length is shorter than Hornby or the bulkhead position is incorrect (I suspect the latter) because the motor bracket wants to stick further into the cab. The bulkhead is poorly detailed so I had no qualms lengthening the lug locating slots to allow the motor bracket to fit, which cut into quite a bit of the detailing. It would be possible to modify the motor bracket to avoid or minimise this modification but once again I wanted to keep the chassis as original as possible.

A new floor was fabricated (to be painted) because on the GBL model it is part of the chassis. The chassis resting block in the photo is where the locating lugs rest.

The bulkhead is not easily seen normally and with driver and fireman fitted even less of  this bodgework will be noticeable.

For those wanting a working Southern liveried locomotive then that completes the project. For me it is not the end. Here is a list of further work I'll be undertaking.

• Correct the front buffer position and size
• Remove the Southern ring from the smoke box door
• Re-livery to BR period, early totem
• Fit nameplates and shield for a west country class
• Fit window glass
• Fit Hornby speedometer cable
• Fit a Zero1 chip
• Anything else that I think of

To Part 5

To Part 1

GBL BoB - Part 3

This is the disassembled locomotive body.

Only the body is required. Note it is hollow with strengthening ribs inside.

Motorised Chassis decisions

My first thought was to 3D print (I have a printer) the chassis, bogie and pony truck and buy a motor, axles, gears and wheels. A nice, cheap project to print some of the components. I looked into the cost of driving wheels and motor, which came to nearly £30 alone so, had second thoughts. It was going to take quite a bit of time to design and not be cheap!

Why reinvent the wheel when Hornby produced a nice motorised chassis. I looked into buying the individual components that make up its motorised chassis, all can be obtained apart from the metal block it seems. I started to total up the cost of parts and gave up when it went above £50. I also looked at a chassis kit available from a kit manufacturer and this came to £35 without wheels and motor.

I went onto Ebay and found several complete Hornby motorised chassis. Snapped one up for £34 + postage not knowing for sure whether it would be suitable but as the GBL model is a copy of the Hornby (albeit the 1980s model) there is a low risk of a serious mismatch.

Here is the GBL body and Hornby motorised chassis. The body internal ribbing needs to be removed and some other modifications to do before they will fit correctly..

Project cost to date £46.98 + tender wheels and coupling from spares box and DIY 3D printed tender chassis.

Average used Hornby model (high tender) price £81.

To Part 4

To Part 1

GBL BoB - Part 2

The tender is very simple to convert from static wheels to running wheels. Here is the tender completely disassembled.

Note the integrated metal static wheels, axles and frame that is discarded. The body is a one piece component that once removed will take a repaint for the BR period without over spray worries for the chassis.

A new axle frame needs to be fabricated and a set of wheels obtained. I used old Airfix/Dapol tender wheels from their BoB plastic kit that were left over when I motorised that model and fitted metal wheels to its tender. The wheels should be the Bulleid-Firth-Brown (Boxpok) style but plain disk wheels were supplied with the Airfix kit. Other disk wheels sets could be used of about 14 mm diameter.

Probably the easiest frame manufacture would be tin plate bent into a U shape like the old Wren Bulleid tenders, but with a 3D printer to hand I designed and printed my own.

It is a two part assembly. The main piece has U cut outs for the axles and the other piece is a lid that holds them in place. The whole assembly is held together with two of the long plinth securing screws from the GBL model. These pass through the two piece frame and screw down into the existing chassis fixing bosses. Glue is not required. The bearing surfaces for the axles are 2 mm long each side achieved by a deep bore slot relief in the middle. Reducing the bearing surface this way improves free running. I used grey PLA plastic for the frame that I had to hand and painted the sides black. Black PLA would be better.

A NEM pocket coupling is contained in the end of the frame by means of a dovetail slot - just like the latest Hornby models. It is a tight fit not needing glue.

In the photo below the finished tender assembly is hooked up to a 'Hatchett' Mk1 coach. The new frame is just visible between the wheels. If I had thought about it I could have designed the frame not to show at all and spent more time designing in brake gear but as the GBL model overall does not have the fine details of the latest Hornby model then it is ok as is for me. The tender will be repainted along with the engine when I have motorised it.

To Part 3

To Part 1

GBL Bulleid BoB - Part 1

This is the one I have really been waiting for and I have to say I'm quite pleased with it, despite reviews at RMWEB that criticise its accuracy to prototype. I have definite ideas to motorise this one and repaint in BR crest livery so I am only interested in the body of which the most distasteful aspect for me is the smoke deflectors that are solid to the body - no gap between. Another part that I did not initially notice until reading reviews is that the front buffer beam is set too high.

What is especially good is that the chassis is a separate component that can be removed revealing a hollow body shell, which should enable a motorised chassis to be fitted with a bit of fiddling. The tender can also be modified quite easily to fit a working wheel set.

I doubt the total cost of the motorisation project will be any less than a good second hand r-t-r Hornby model but I'll be doing it for the pleasure.

To Part 2.