Bratag
Barton & Lucas are well known for their tracked vehicles, for off-road use. But so far, they have always used at least two parallel tracks. The YCK-67 was a technological oddity with its bending tracks to steer. But the Bratag that evolved from that is a great machine that has none of the downsides of the YCK-67.
Design
A single band of track is guided around four big wheels, two on the ground for and aft, and two higher up. In the front the tracks makes an angle of 37° with the ground, for easy obstacle climbing. In between the two ground wheels, two sets of double rollers are placed to spread the weight of the machine over the length of track that touches the earth. Resulting in a ground pressure of just 0,03 at.
The rollers and the two big wheels on the bottom are suspended, and the forward facing wheel has a spring to compensate the movement of the suspension. The rear wheel is made as a sprocket and is driven.
Nestled in between the bottom and top part of the track lies the oil fired steam boiler. With fuel-tank, water-tank and condensor in the front. In the rear is a reversible double acting single piston engine that drives the sprocket that pulls the track around.
Where the YCK-67 had a massive play in the hinges between the plates of the track to allow the bending. The track of the Bratag is constructed differently. A single steel cable is spliced into a loop, and on this cable the track plates are clamped. The clamps form a center ridge along the inside of the track that is used to keep the track center on the wheels.
The machine steers by means of steam powered pistons that pull or push the front and aft wheels into an arc. Due to the construction of the frame and the position of the hinge points, when steering it pushes the rollers in the bottom outwards.
The top of the track is covered from the rear sprocket to about 3 fists from the front. A leather seat is placed in the middle, with a set of footrests on either side of the boiler. The Bratag is controlled with the handlebar that is placed in front of the driver. Turning of the handlebar controls the flow of steam to the pistons that bend the track, allowing turning.
The speed of the machine is controlled by a foot pedal on the right side. Pushing it down opens the steam valve more, and releasing it closes the steam valve with the help of a spring.
Racing
The excellent off-road capabilities of the Bratag has inspired people to use them in cross-country racing. Mostly young nobles compete with each other regularly, the distances of the races vary as does the terrain.
Non of the Bratag's they use is still original. Most have changed out engines, boilers, fuel tanks, to gain power, and some even drilled holes in the track plates to save weight.
Military use
The Army uses the Bratag for messengers and scouting.
Body: 4 f
Track: 2 f
Track in contact with earth:1 p 7 f
Top of handle bars: 9 f
Crosscountry: 5 M/h
Crosscountry:25 Marches
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