The Medium Mark B

The Medium Mark B was the result of Sir William Tritton, one of the designers of the Mark I, not including the other lead designer, Lt. Walter Wilson, in the development of the Medium Mark A. When it was felt that the Mark A was underpowered, Wilson, now a Major, began developing a replacement, the Medium Mark B. Unfortunately, due to the fact that the prototype wasn't completed until September 1918, it never had serious production - only 102 were built, and only 45 of those entered service.

The Medium Mark B looks like a Heavy tank shrunk down and with a larger casement on top. Like the Mark A, it was armed only with machine guns. It carried four Hotchkiss guns that could be moved between ball mounts. The casement had two mounts forward and one each on each side and the rear, while two were mounted in the hull doors, allowing for two guns to face forward or to either side, and one to the rear. Wilson flipped the arrangement of the Whippet, placing the engine in the rear and the casement at the front to improve driver visibility. This had the downside of making the engine harder to service from inside the vehicle.

The Medium B had a slightly stronger engine than the A, increasing horsepower from 90 to 100, but it was also heavier, at 18 tons to the A's 14 tons. It ended up being slower, with a top speed of 10 kilometers per hour, but thanks to additional fuel and a more efficient engine, its range was 150% of the range of the Medium A. The Medium B also had the ability to lay a smokescreen by emptying a reservoir of sulphonic acid on its exhaust pipe.

While the armor of the Medium B was not thicker than the Medium A (remaining at 6 to 14 millimeters of steel), it had greater slope on the nose. The sides are essentially flat slabs with no slope, like the Heavies.

The Medium B was a decent design, but one that had made compromises to allow the tank to fit on a single railroad flatcar. This limited engine size (and thus speed) and trench-crossing ability. One concept that was never built was a Medium B Male with a 2-pdr (40mm) gun mounted fixed in the casement. This would have made the Medium B a potential tank-killer well into the 1920s, but given the lack of tanks for it to fight, the failure to build it made sense.

Surviving examples: None.

Medium Tank Mark B
 Fire Control 0
Armament: Four Hotchkiss Mark I. Two mounts forward, two left, two right, one rear
Stabilization: None
Ammo: 3000x7.7mm
Fuel Type: G, A
Veh Wt: 18 tonnes
Crew: 4 (commander, driver, machinegunner, loader/mechanic)
Mnt: 9
Tr Mov: 10/5
Com Mov: 5/2
Fuel Cap: 386
Fuel Cons: 40

Config: Veh
Susp: T: 4
HF: 4
HS: 1
HR: 1
TF: 2
TS: 1
TR: 1

For those who want to use the never-developed Male, the QF 2-pdr has the following stats:
40mm L/39 QF 2-pdr Autocannon
ROF: 10 Rng: 315
HE: C:1 B:8 Pen: Nil
KE: Dam:9 Pen: 6/5/4/3
No Case shell available.
Standard load is 14-round belts