The Medium Mark C Hornet was designed as a replacement for the Medium Mark A Whippet but arrived too late for service in the First World War.
The Medium Mark C was designed by Sir William Tritton, one of the co-designers of the original Mark I. It was developed at about the same time as his fellow co-designer W.G. Wilson was working on the Medium Mark B Whippet.
Both men came up with a similar design. The Medium Mark A Whippet had a long low fuselage carrying the engine at the front, with a fixed turret forming the fighting compartment at the rear. Both the Mark B and Mark C reversed the layout, and placed the engine at the rear and the fighting compartment at the front. They both also used a standard looking Rhomboid shape for the hull, although in both cases it was lower than on contemporary heavy tanks. The Mark C was larger than the Mark B- 3ft longer and 1ft taller (although the same width). Compared to the Mark V it was only a few inches shorter, actually slightly taller, but two feet narrower than the female and 9 tons lighter.
The Medium Mark C was big enough to take a standard 6-cylinder Ricardo engine and the normal transmission from the Mark V tank, with the engine at the rear and the gearbox and epicyclics in the centre of the tank. There was plenty of ventilation above the central part. The extra space in the Medium C meant that it didn’t suffer from the same over-heating problems as the Medium B.
The crew compartment was similar to that of the Medium B, and was a fixed turret. The driver sat in the centre at the front. The commander had a cupola at the back of the turret to give him a better view. The two gunners could move their guns between five ball mounts for machine guns around the turret. Voice tubes were installed to improve communication between the crew. It was built out of a number of sub-assemblies to aid with mass production. Although it was heavier than the Medium B its more powerful engine meant it was faster, although at only 8mph it could hardly be described as fast.
Plans were produced for a male version of the Medium C. This would have been armed with a 40 calibre length 6-pounder naval gun, the same gun that had originally been used in the Mark I Tank. It would have been carried in the front of the superstructure, firing over the driver’s head, and was meant to be a tank destroyer.
Work on the Medium C began in July 1917 and the first prototype, known as the Hornet, was completed in August 1918. Sources disagree on the total number ordered – either 450 or 600, all from Fosters of Lincoln. Only 48-50 of these were completed.
The Medium C is often said to have been the best British tank design of 1918, although its limited service means it is hard to justify that claim. It was used as the main equipment of the Tank Corps until 1923 when it was replaced by the Vickers Medium Tank, although in this period the Tank Corps was massively reduced in size.
During the General Strike of 1921 a detachment of Medium Cs was sent to Glasgow to support the authorities, although probably with little effect.
Hull Length: 26ft
Hull Width: 8.33ft
Weight: 20 tons
Engine: 150hp Ricardo
Max Speed: 7.9mph
Armament: Four machine guns