Tamiya BT-7 1935 (thanks Russell Hall)

First published in the October 2010 AMMS Brisbane newsletter

Opening the Box

I received this latest release c/o Brad Littleboy a week before the QMHE. Initial inspection shows some very crisp mouldings with minimal knock out pin marks to contend with, as I discovered later the majority of these were hidden when parts were assembled. The instructions give you 5 different build/marking options and Tamiya have also included a 2 page colour sheet of walk around pictures taken from a museum example The box also includes a couple of figures inspecting a map and a length of chain.


The BT tanks were convertible tanks; the design was based on a design by J. Walter Christie. The idea was to reduce wear of the unreliable tank tracks on the 1930s. It would take the crew of 3 approx 30 minutes to remove the tracks and engage a chain drive to the rearmost road wheel on each side. This would allow the tank to travel at high speed on roads, specs show that it was capable of over 70kph, in wheeled mode the front road wheels were steerable, however, Soviet tank forces found this conversion of little practical use considering the minimal number of paved roads so this feature was dropped in later designs. The BT series also had the option of additional exterior fuel panniers which were mounted on top of the track guards.

More reference and options

I was able to obtain a book on the BT series from the QMHE, this also included a disc of pictures from a museum subject. Although the book is entirely in Russian there are quite a few pictures including some in wheeled mode with the tracks stacked up along the top of the fenders and even 1 showing this with the front wheels posed in turning mode. The tracks appeared to be in 3 runs with 2 vertical and then 1 horizontal, straps are also shown to hold these in position. A decision was made to build in this mode.

Getting started

The 1st 5 parts of the instructions deal with the lower hull and suspension including the steering mechanism for the front wheels. The front wheels are mounted on swing arms with a hub and steering controls similar to a car. In step 8 of the instruction I have added the hubs "A14" at an angle to depict front wheels turned and at the same time lengthened 1 of the steering arms and shortening the other. Tamiya give us the option of showing the driver’s hatch open, they have given you the driver’s seat but some additional detail in this area would have been nice so hatches will be closed. The only fit issue was the upper hull as shown in step 12, when attaching to the lower hull it just didn’t want to fit, fitted well at the rear with that familiar Tamiya "click" as we all know but the front portion was an issue. Once glued in place there was a slight gap left of the front edge as well as the 2 sloped edges, this was filled with liquid putty and then later smoothed back with some thinners – problem solved, I might add here that this was the only time that any filling was required on the entire build.

Tamiya Etch

Tamiya have supplied an etch engine or exhaust cover in the kit, they have also supplied jigs to get this into shape – refer to step 13 in the instructions. This works very well as they not only supply a jig to roll the etch over to create the curved surfaces, they also supply a die to press the etch into to finalise the shape. A portion of 1 of the jigs is then removed and used to mount the etch onto on top of the hull – very clever. They also supply etch grills to be added to the radiator intakes, there are tiny recesses for these to fit into and once again the fit was perfect.

Adding stuff

Closer looks at the reference pictures show a spring attached to the vertical drivers hatch going into an opening on top of the hull. The lug is on the hatch and the opening port is also on top of the hull. I made a small coil spring from copper wire, drilled some holes and added it, 20 minutes of bad language and all done.

Moving on

Radiator intakes, fenders, engine hatch, hooks, lights and horn were all added to hull so time to move onto the turret. The barrel is in 2 round pieces which are butt joined so no join seam along the length of the barrel to contend with. The gun breach is movable with interior detail being the breach as well as the 7.62mm coaxial machine gun; the complete assembly is added to a mounting plate for the front of the turret. The turret is moulded in 2 halves with a complete separate top plate and rear hatch. If you are building option "B" then some holes need to be drilled for the mounting of the circular radio antenna. The turret halves and top plate all go together well with the gun mounting plate and rear hatch covering the joins. Hatches on the top plate could be left open but I have closed and then added the lifting lugs and other details to the top of the turret,


The kit contains length and link as well some individual links to make up the curves around the wheels with the top run has been moulded with a sage. I am mounting the tracks on top of the guards so this created bit of an issue, 1st straighten the top run and 2nd I would need to do some cutting and shutting to obtain the 3 equal lengths per side, doing this would loose the join detail. I have ordered a set of Fruilmodel tracks to get around this; the only issue will be the weight on top of the guards so 1 run of plastic tracks will be used. I will need to make the straps from something but already have an ABER Buckles and Straps set so am half way there.


Normally I would opt for Modelmaster Russian Armour Green, Tamiya have called out a 50/50 mix of their XF4 – Yellow Green and XF-58 – Olive Green so I will start there. I also have a couple of Lifecolour Colours which are actually FS colours but look close to what I am looking for. I will try these for a bit of post shading. I am not exactly which marking option I will go for as yet so a bit more research will be required.


Tamiya have once again produced a gem as far as fit and design is concerned. As a straight out of the box build then you can’t really go wrong. Some additional details for the interior would have been nice but am sure the aftermarket boys will take care of that.