Vickers Medium Dragon


The Vickers Medium Dragon was a fully-tracked British field artillery tractor made by Vickers Ltd., produced in various versions from 1922 to 1937. It was developed from the carrier version of a 'Tropical Tank' designed by Lt-Colonel Philip Johnson, using components from the running gear of the Vickers Medium Mark I tank. The Mark IV version of the Medium Dragon was effectively a complete re-design, using the running gear from the Vickers 6-ton tank which was not adopted by the British Army. The Army finally decided in 1935 to purchase only wheeled artillery tractors, and no more were sold in the UK, but the Medium Dragon Mark IV sold well in export versions up to 1937. The Medium Dragons towed a wide range of artillery, from 18-pounder to 60-pounder guns.
From c1929 Vickers-Armstrongs also made the Light Dragon tractor for towing light artillery, with a similar name but of a completely different design based on early versions of Vickers Light Tanks.

Design and development

Although there had been previous efforts to motorise heavy artillery transport duringthe First World War variant.
The engine, an Armstrong Siddeley air-cooled petrol V-8 of 90 hp was installed at the front on the left, with radiator intakes/louvres in the front panel. Unusually it had rear wheel drive, like the Medium Mark A Whippet and Vickers Medium Mark I and Vickers Medium Mark II.
The 9th Brigade RFA took delivery of the supply variant in August 1922: subsequently two more prototypes were built, named the Vickers Dragon Nos. 1 & 2 Artillery Tractor. Whereas the Light Infantry and Tropical Tanks used a novel wire rope suspension, the prototype Dragons had conventional coil suspension based on the Vickers Medium Mark I, with 11 small road wheels and 6 return rollers. This system was carried into production.
Vickers began a limited production run in 1923, with the delivery of 18 Dragons Mark I, initially towing the Army's main field piece, the QF 18-pounder gun.
During 1923-4 the first two field artillery brigades were completely mechanized. At the same time the Royal Tank Corps, which had been placed on a permanent footing in September 1923, acquired its first Vickers Medium Tanks.

Production history

The Medium Dragon was produced in four main versions, Marks I-IV.

Dragon Mark I

11 road wheels, six return rollers, side skirt running the length of the tracks like Johnson's 'Tropical Supply Tank'.
The nine crew members sat on three rather exposed forward-facing benches, plus a commander and driver in front.
Two were converted by the Royal Ordnance Factory Woolwich for use by the RAF Armoured Car Company when the RAF took over responsibility and control of Mandatory Palestine, Trans-Jordan protectorate and parts of Iraq from 1922. The crew benches were removed, and an armoured body fitted with the turret from a Rolls-Royce armoured car. One was further transformed into a boxy armoured personnel carrier with rifle ports in the sides.
Experiments were also made with the Mark I Dragon to use it as a Bridge carrier, with a footbridge. The two detachable steel beams which were carried on the side skirts of the Mark I may have been connected with this. By 1926 a Vickers Medium tank had also been adapted to be a bridgelayer, but with only a 16-foot light girder bridge, it was found to be of no practical use.

Medium Dragon Mark II

Distinguishing features include 11 road wheels, and five return rollers. The side skirt /mud chutes with 7 square holes, two vertical bars linking the side skirt to the main body. Headlights on stalks. Prominent upwards-facing triangular air intake in the centre of the front plate.
There was accommodation for eight men sitting sideways inside, plus two on rounded leather? seats at the rear aft of the ammunition boxes, plus a commander & driver at the front.
A Pathé newsreel shows King George V at Aldershot in c1923 watching Army exercises, including his inspection of a Medium Dragon Mk II.
The Medium Dragon Mark II* had some minor changes, including re-designed ammunition boxes.

Medium Dragon Mark III

The Mark III appeared in around 1929. The tracks had 11 road wheels, and six return rollers. The solid side skirt/mud chutes had four oblong holes. Five vertical bars linked the body to the side skirt. The headlights gained modern-looking faired housings. The air intake appears to be situated on the rh sloping front plate. Squared-off seats aft of the ammunition boxes at the rear of the body.
The Mark IIIB had modified mud chutes/sideskirts with three large oval holes and two smaller vertical oval ones at each end.
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The Mark IIIC had extra armouring apparently protecting the left-hand side crew. The headlight enclosures were squared-off, and the triangular engine cooling intake was turned downwards-facing on rh side front plate.
A 1942 US manual on the British Army shows a Medium Dragon Mark IIIC towing a BL 6-inch 26 cwt howitzer.

Medium Dragon Mark IV

The Mark IV of c1932 was essentially a complete re-design, incorporating the running gear from the Vickers 6-ton Light Tank Mk II : eight road wheels in two sets of paired bogies, quarter elliptical leaf spring suspension, and four return rollers. The side skirts on previous models were removed, leaving the running gear exposed. There was a distinctive shape to the tracks with the top run angled upwards towards the front.
Only twelve were sold to British Army in 1935, which adopted the official name of Dragon, Medium, Mark IV: some of these went to France with the BEF at the start of WW2.. The UK versions were fitted with an AEC 6-cylinder inline water-cooled diesel engine as fitted to London buses. Export versions were powered by an Armstrong-Siddeley Puma petrol 4-cylinder engine developing 91.5 bhp.
In 1935 the Army decided to concentrate on using wheeled vehicles for towing all the army's artillery, and the procurement of tracked artillery tractors was dropped. Nevertheless, Mark IIIC Medium Dragons were still being used in 1942.
A cargo version of the Medium Dragon Mark IV was also produced.
Vickers exported considerably more Mark IVs to foreign armies. In 1932 one vehicle was sold to the German company Siemens-Schuckert; in 1933 Finland bought 20, and the same year 26 Mark IVs in an anti-aircraft version were sold to the Siamese Army, armed with a QF 2-pounder naval gun. 23 were sold to China in 1935 and India bought 18 tractors in 1937.
According to David Fletcher, the running gear used in the Mark IV Dragon was the basis of the Matilda I tank. During trials of early Matildas in 1936 the track pins failed constantly, and the rubber-tyred road rollers were replaced with steel ones: but these faults weren't cured until 1937.

Variants

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