First published in the January 2011 AMMS Brisbane newsletter
In 1918, the British expected the Germans to fall back across Belgium, using the Low Countries’ canals to form new defence lines. This created the need for bridges that could support the weight of tanks crossing the canals and could be laid down while under fire. The standard distance between the canal lock gates was 20 feet, meaning that the bridges had to be slightly longer than this and consequently weighed about four tons – perhaps enough to tip a tank over when hanging off their fronts. The response was to adapt existing Mark V Star and Mark V Two Star tanks to carry the bridges. At 35 feet and well over 30 tons, as these had enough weight to provide ballast behind the nose.
There were two bridging designs developed and in the example in this article, the frame for supporting the bridge in front of the tank was based on standard Royal Engineer components, mostly interlocking pipes. The rear end of the bridge was balanced on a bar across the front of the tank. The front end was suspended from chains that passed from the tank over the pipework frames. These chains could be lengthened or shortened, using a winch on the tank’s roof. As the tank pushed the bridge towards its intended resting place, the chains were lengthened so that the bridge’s front end dropped towards the ground. When it hit the ground the weight was taken off the chains, which consequently dropped that end of the bridge. The tank then reversed, so that the bridge’s rear end fell to the ground on the near side of the canal. With both ends of the bridge grounded, the tank crossed over.
"Simples" as the Meercat says in that annoying T.V. commercial. The idea worked but it was not used in action because the war ended before development was finalised.
The Model Tank
The model is based on the Cromwell Models 1/72 scale Mark V Star, which is simple to build and ideal for someone new to resin kits. Resin is too brittle to cast well in very thin sections, so I replaced a few of the kit parts with scratch-built equivalents, mostly shown in white on the photographs.
Mud, Glorious Mud.
I wanted my model tank to appear in wet, glutinous mud of the kind that sucks your boots off when you walk across it. This kind of mud gets scattered all over the place when churned up by forty tons of tank and bridge passing over (or rather through) it.
To model this effect, I began by making an evil looking cauldron of resin, household plaster, gloss varnish and brown paint. When it looked so horrible that I fantasised about applying it to the boss’ car, I took a spatula and applied it to the model instead. Most of it went into the ground work but a fair sprinkling went onto the tracks and lower sides of the tank and bridge. I then added more varnish into the mix where it was representing wet mud on the ground, tracks and anywhere else where the water would collect.
To model dried mud stuck on the higher parts of the tank that would not get constant soakings, the process was the same, minus the varnish. If you have difficulty imagining where mud will stick, ask a child.
For the muddy stains dripping down the tank sides from the tracks, it was a simple but delicate case of using a paint brush to draw diluted oil paint from top to bottom in narrow lines, using a mix of browns from very dark to almost white. The darker and shinier the colours looked the wetter the appearance of mud.
The Bridge and its Frame
The basic shape of the bridge was built using flat plastic card for the main frames and plastic card with rivets embossed for the joints and plated surfaces. The pipes used to make the frame and the cables lead-ing over it were modelled from plastic rod.
Some of the plastic representing surfaces and cables needed to be curved. It is simple enough to bend rod or card to shape but the problem is that it springs back when you let it go. This can be prevented if you hold the plastic in its curved position in very hot water for a few seconds – but few of us enjoy holding our hands in almost boiling water. Use elastic bands to hold the plastic in position on a frame and water-proof/heat resistant gloves (I look good in Marigolds) and tongs to hold it in the water.
If you are aged under ten or over nine, please get a sensible adult to supervise this work as scalding can hurt. Take care!
I originally intended to build the model with the bridge balancing on the bar at the front of the tank, but decided that this would be too fragile. Instead, I placed one end of the bridge under the tank’s tracks, as though the tank was pressing it down and lifting the front end into the air. It’s not as dramatic as the original idea but it’s a great deal more likely to survive travel to and from shows.
That Steely Look
When a bridge and a tank knock against each other, the paintwork gets knocked off. I represented this on the relevant parts of the model by using a 9B graphite crayon. Graphite crayons are available for a few pennies in art shops. Passing one lightly over the bridge created an effect similar to dry brushing, with the edges and raised details all gaining the steely look.
This was an interesting project. Working out where all the bridge components went took some time but once I’d done that, the shapes were simple to make from plastic rod and plastic card. The muddy appearance took a lot of work but was fun to apply and could be adapted for other models. The whole thing is unusual enough to attract attention and hopefully, there&rsuqo;s some decent modelling in there too. Painted in standard World War One colours and covered in model mud, I consider it my Big, Brown, Beautiful Bridge.
Commercial Parts List
Mark Five Star Tank from email@example.com
Mud resin and colouring powders from firstname.lastname@example.org
Name plate from NameIt@fsmail.net