BUILDING A TUNNELLING ENGINE by Eddie Lund
Driver Eddie Lund builds the Bowaters Models Hunslet locomotive kit.
The moment I saw the Bowaters Models advert for their 16mm Scale Hunslet Tunnelling Engine “Emma” in Garden Rail, I just had to have one. You see, I am fortunate to drive one of this type of loco on the Leadhills and Wanlockhead Railway. Luckily, with Christmas only a short time away, it also made an ideal pressie from my dear wife.
The prototypes were a fleet of five locomotives that were used on the Jubilee Line extension in London in the 90s. Hunslet Locomotive Works, Leeds, built the LWR loco in 1994, works no. 9348. These 0-4-0 locomotives have a 6-cylinder air-cooled Deutz diesel engine producing 63kW (84hp) horsepower to the four wheels via a hydraulic transmission and axle-mounted gearboxes.
The kit comes with an optional ready-tobuild motorised chassis from PDF Models. On looking through the building instructions, it all seemed very easy to build, albeit, in my opinion, a very basic model with no interior detailing. My only real concern was the fact it was made from acrylic plastic, a medium I had not used before, and I was unsure of what type of glue to use to put it together. Rather than experiment and potentially damage parts, I decided to use slow grab superglue, which worked quite well.
The design represents the prototype after modifications by Alan Keef Ltd, carried out when the tunnelling job was finished. A new full height cab and windows are the main differences.
The model has a flat uniform floor level including the cab area, whereas the prototype cab floor is about 12” lower than this. I could see this was going to give me some problems, as I wanted to put in some fairly accurate detailing inside the cab and I wasn’t going to use the supplied cab door, which would have hidden the height difference.
Anyway, I decided that I would split the construction into two, first the chassis and body and then my more elaborate cab area. The separate chassis, motor and wheels were a doddle to build with no gluing required, all parts being screwed together. This then sits within and is bolted to the floor of the body.
The body, excluding cab, is made up of eight parts that require gluing, giving a very basic outline. As both upper body sides with their prominent grill apertures looked very naked, I put in some elementary detailing.
I would also have liked to have modelled the fuel tank filler cap and the air filter intake cap on the top of the offside body but couldn’t due to the way the kit has been designed. The one-piece top sits just inside the top of the sides to allow easy access to fit in R/C and batteries. On the prototype this area is a single piece, allowing for the intakes to be built in at an angle.
The lower front and back body panels required sand boxes and associated pipe work, another fiddly job but nice to see when completed. The upper ends both required airline outlets, a flashing beacon as well as head and taillights, all of which I wanted to be working. Determined to have all my lighting cables running through the cab hidden, it took a lot of head-scratching to achieve something fairly close to the real thing.
Cab detailing took a long time, and I’m still not 100% happy with it. I wanted to model the front instrument panel better but found I couldn’t print out the necessary images small enough with any great detail. The other cab parts were made up out of styrene and any bits and pieces that I thought would resemble the real thing. When all the detailed parts had been made, it was time to put them all together, taking into consideration whether each part should go in before or after painting. As I had built the cab in two ½ “L” shaped pieces, it was carefully stuck together and then on to the already painted body.
I had not taken up the option to purchase Accucraft couplings and made multi-height ones to match my rolling stock. I also drilled two holes in the body, one on the nearside for the exhaust outlet, the other on the front below and to the right of the fan grill, which, on the prototype, is there to allow a tool to be inserted into a pulley boss on the front of the engine, allowing it to be turned by hand.
As supplied, the kit is a very shiny dark blue, but as the LWR loco is still painted all over in it’s tunnelling white, I decided to keep mine the same. This did have advantages when it came to painting, not having to mask off the outside from the inside. However, after cleaning and giving all a coating of basic rattle can grey undercoat and then the top white coat, I found that the paint was very easily chipped. I’m not sure which to blame but either acrylic doesn’t work with rattle cans, or possibly I didn’t allow enough drying time between coats.
Luckily, one of my Humbrol paint tinlets almost exactly matched my chosen spray can shade of white. In an effort to protect the paintwork, I gave it all a finishing coat of clear varnish. At first, this seemed to have the desired effect in that the paint didn’t seem to chip, but after a few days, the paintwork had developed a little crazing in places, something I’ll just have to live with.
Final construction activities were to add my own windows and floor, cut respectively from clear, and a piece of painted, embossed styrene sheet.
Turning my attention to fitting R/C equipment and rechargeable battery. I use the Micron system, which gives options for controlling lights and sound if so fitted. I’ve not fitted a sound card yet but did find that a cheap buzzer gave a suitable noise for a horn.
Having got all wires soldered to a piece of PCB, the moment of truth arrived. At this point, after switching it on, I came across a fault. In an effort to keep the number of wires in the cab area down, I had used a common return wire from the rear panel LEDs. Somehow this wasn’t working on the red LED, but with everything assembled and painted there was no way this could be repaired. So, now I have only a red showing at the front when the loco is in reverse.
I’ve really enjoyed building this kit, and if I were to do it again, I’d now have more confidence in the plastic medium. I’m pleased to say the loco runs well and, with the extra effort, does look quite like the real thing. ■