Building the 'Chocolate Zephyr' (GT3)

[cctransuk]

Thanks for the kind comments, Likes, etc. - much appreciated.

 

I'll now set out a few random thoughts relating to this (rather protracted) build.

 

The Golden Arrow resin body kit, ( http://www.goldenarrow.me.uk/products.htm ); is, it transpires, some 4 mm. too short, though I didn't realise this until I placed the body over the High Level chassis kit - ( http://www.highlevelkits.co.uk/ ). The lack of length is also apparent when measured against a drawing - I used :-

 

 

 

I felt that the missing scale one foot was noticeable, and made the model look somehow 'stubby' when compared to photos of the prototype. I therefore purchased a second main body moulding in order to cut-and-shut the two to produce a scale length body.

 

The detail on the body moulding should be treated with suspicion, as several features did not seem to match the drawings and photos to hand; it is, however, relatively easy to amend / fill / replace and add to the detail using plastic card and strip.

 

The cab roof / rear / door moulding needs attention; the roof being too short and lacking the rear overhang. Extend it front and back with plastic strip and cut back the bonnet on the main body moulding to suit. (Vertically project the front of the lower cabside with a straight-edge to determine how much to extend the front of the cab roof). I could not drill the edges of the cab doors for handrail stanchions without breaking the resin, so I replaced the doors with ones laminated from plastic card.

 

Photos that were passed to me during the build prove that the bonnet exhausts did not have grilles - they were just open 'trenches' lined with sheet metal.

 

It's a pity that the etches for the cab windows are not produced in nickel silver; ( http://www.rmweb.co.uk/forum/viewtopic.php?f=8&t=46203 ); silver paint is never a convincing representation of polished aluminium.

 

I fabricated replacement cab steps / vacuum cylinder shrouds from nickel silver strip and plastic card, with etched brass chequer-plate kick panels between the steps.

 

The running board walkway was surfaced with etched brass chequer-plate - this is a little thick, and I wonder whether resin-printed waterslide transfer chequer-plate from Archers would have been more subtle.

 

The resin-cast 'hub-caps' for the coupling rods are centrally drilled and, as such, seem to be intended for fixing th the crankpins. This would result in them revolving with the wheels - which is incorrect; they are an integral part of the rods. I filled the holes in the 'hub-caps' with plastic rod, and then very carefully hollowed the rear of the mouldings with a ball-ended cutter in a minidrill.

 

I used Markits wheels, with matching etched axle-nut covers secured with Markits deluxe crankpins. The crankpin nuts / bearings were recessed into the coupling rod bosses by counter-drilling the rods. Once the 'hub-caps' had been painted, and the coupling rods polished and fitted for the final time, the 'hub-caps' were placed over the recessed crankpin nuts, centrally on the rod bosses, and secured with tiny drops of cyanoacetate glue applied with a needle.

 

The handrails and stanchions on GT3 were chrome-plated. As, to the best of my knowledge, nickel silver handrail stanchions are not available, I resorted to sterling silver 0.8 mm. dia., half-round wire, clenched into split-pins; see (http://www.rmweb.co.uk/community/index.php?/topic/122522-chromed-handrail-stanchions-knobs/ ). 0.8 mm. is a little large, but all that I could find in the UK. (0.6mm. is available from the US, but the shipping is three times the price of the wire)!!

 

For some unfathomable reason, the etched GT3 numberplate has come out deeper than my transfer for the same item. The transfer seems to be correct, but I'd already securely fixed the etching and painted the body before this became apparent. If using my transfers; (see Sheet BL149 at https://www.cctrans.org.uk/products.htm ); just cut two rectangles of 0.25 mm. plastic card to match the transfer dimensions, and round off three of the corners before fitting them to the cabsides.

 

The corridor connections front and back of the tender are flexible rubber mouldings, which can be obtained from a number of suppliers. That between the loco and tender was a cut-down BR Mk.1 type, whereas the one on the rear of the tender was a suspended British Standard pattern.

 

As the flexible fuel and water connections between the loco and tender are quite prominent, I represented them with black flexible plastic beading cord. At the loco end they were glued to the back of the cab steps, whereas the tender ends of the connections had tiny rare-earth magnets glued on with cyanoacrylate. Matching magnets; (get the polarity right !); were glued below the tender running plate. Holding the magnet ends of the flexible connections close to the magnets on the tender will induce self-coupling !

 

The cab interior was knocked-up from plastic card, following a layout diagram and screen-grabs from the BTF GT3 film and a digital version of GT3 from a PC simulation game.

 

That's about it really - if you have any questions don't hesitate to ask here, or you can PM me if you need prototype images of any particular feature - if I have it, you're welcome to it.

 

I have a spare pre-production version of the etched chassis kit; it lacks some of the final content but you can PM me if you're interested.

 

Building GT3 has been a very interesting project - thought-provoking at times and needing some techniques that are new to me - but I am very pleased with the result.

 

 

Regards,

John Isherwood.

Edited October 8, 2017 by cctransuk

[Staffordshire]

    Excellent thread, learnt a lot from following it ....

 

    Not in the same class, but have added a photo of my GT3 built from mainly the same components, other then the High Level chassis ....

 

    Comments welcome...

[cctransuk]

    Excellent thread, learnt a lot from following it ....

 

    Not in the same class, but have added a photo of my GT3 built from mainly the same components, other then the High Level chassis ....

 

    Comments welcome...

 

Very nicely done - congratulations.

 

Regards,

John Isherwood.

[richard i]

You can see the difference in the coupling rods but it does not stop it being a great model.

Mine has the same issue.

Richard

[Clive Mortimore]

Better get on with my scratchbuilt effort. Here it is playing at being at Rugby testing station. Honest its wheels were going round when I took the photo.

 

 

Body plastic card. Chassis brass, with Romford wheels and I cannot remember the motor or gear box.

[D River]

Some interesting thoughts and excellent models on this thread - just to add a bit to it, whilst researching GT3 and looking for drawings (other than all the versions in the model press down the years) I came across a couple of things that may be of interest.  First is a paper by J O P Hughes of English Electric.  It can be found here:  http://journals.sagepub.com/doi/pdf/10.1243/JILE_PROC_1962_052_021_02

 

Second is the J O P Hughes archive at the NRM.  I haven't seen the latter, but it looks to contain various drawings: https://www.railwaymuseum.org.uk/sites/default/files/2018-03/Hughes%2C%20J.O.P.%2C%20Designer%2C%20Introduction%20%26%20Archive%20List.pdf

 

I have added a couple of image grabs from the first item that show both the frames and cab details. Note that the handbrake wheel is on the bulkhead behind the firemans seat - there are a couple of invaluable construction shots of the cab rear and tender front in "Modern Locomotives Illustrated" issue 174 which make it clearer.  The whole GT3 article in that publication is a good source of varied photographs from different angles for anyone considering the build, just ignore the crankpins in the wheel centres on the accompanying drawing...

Edited May 2, 2018 by D River

[martin_m]

Thanks for this extra info, it certainly adds to that already published.

The ILD paper provides some more interesting pictures.

I haven't had time to have a thorough search through the NRM list but it looks promising.

A YouTube popped up recently, 'Strange Locomotives - British Rail GT3' which has a colour view of the other side!

martin