Building 'River Avill' No 797

see movie of this loco in action


Well known modeller, Bernard Taylor came up with a drawing of an Armstrong Whitworth narrow gauge diesel electric locomotive of the early 1930s. He then went ahead and has just produced some first class etches of the model. It is designed to fit on the Bachmann Class 08 chassis.

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If Eastleigh had wished to experiment with this concept, as well as its new railcar programme, a single unit would have been inadequate. They would have expected at least as much traction as produced by their Mallet design. I have therefore redrawn the loco as a double articulated unit.

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Bernard very kindly drew out a different front which in my mind was more appropriate to fit in with the Eastleigh design concepts. We received the first set of etchings, and very nice they are too.
click on images to enlarge

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small part identification - click on image to enlarge
The test etch from Bernard , I must admit contains many lovely bits which frankly I cannot figure out where they go! I am sure that this will be resolved once this kit goes on sale. Seeing as my own model is going to be quite different, I have ploughed my own furrow. After cutting the fret to remove one panel, the first job was to sweat on the panelling. Great care is needed to prevent solder spreading around. The grills were soldered at the rear.

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click on image to enlarge
The fret was then folded using a bending tool. Bernard was kind enough to include a different front which I felt was more in keeping with the County Gate style. This was also folded as was the outer panelling. The front was then soldered to the assembly.

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The buffer beam and lower valance were then attached. To cross members were soldered at roof height with captive nuts to attach the roof.

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The roof is made from flat brass sheet. The profile of the roof is built up from car body filler. Below, the body is on the outside frames of a class 08 chassis.

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as far as we can go for now - click on image to enlarge
The second fret arrived and shortly afterwards, two Bachmann chassis and a cow catcher set from Langley. The next body went together nicely. As the two chassis are to be operated back to back, the wiring of one needs to be reversed. The coupling box at the front of each chassis was removed and a small hole drilled through the chassis to take a fine brass wire that will become the pony truck pivot pin.
The pony truck was fabricated from the four wheel bogies supplied. Axle boxes were made out of small bore brass tube filled with solder. A fine hole was drilled in these to take the needle point wheel sets.

I have experienced several loose wheels. This is what I suggest:

On initial stripdown, degrease axles and wheels and run into the wheel boss, a small quantity of Locktight 603 and leave overnight. This should prevent these stupidities.

Several phosphor bronze are often on in contact with the wheels....check for this..

Positioning of the Roco cylinders. Remove motor. Use 5 minute epoxy to attach and have the return crank already fitted into the rear crank. There is then a short window of opportunity to ensure that there is free movement of the gear.

Once the cylinders are fastened, push the chassis along to check for any binding between the coupling rod and the slide bar support bracket. Only then replace the motor but glue this in position as well, as the extra weight of the valve gear can cause the motor to 'jump' and strip the gears.


Chassis with pony truck fitted. The chassis is extended with plastic strip.

the underside of the chassis. One wheel has been grounded to the axle. The pony truck is yet to be weighted.

 The modified keeper plate showing pony truck retainer pin. The height of the pony truck pivot will be maintained with a spacer.  - click on image to enlarge

The start of building the steel corridor connection. To prevent short circuiting between the two opposite polarity bodies, much of the corridor connection had to be replaced by plastic. - click on image to enlarge

The pony trucks are now weighted with lead and the chassis link added. I realised afterwards that the two chassis are of opposite polarity, so the drawbar had to be divided with a plastic centre section - click on image to enlarge

 The chassis are wired up to a DZ 143 Digitrax chip. The extra wiring is for the directional lighting- click on image to enlarge

 The bodies have been painted and detailed and the interior cavity filled with lead shot wherever possible!- click on image to enlarge

the completed 'River Avill' on Simon Coward's Isle of Mudd layout- click on image to enlarge
photo by Mick Thornton