Mark IX tank

Mark IX

Mark IX
Production history
Designer Lt. G.R. Rackham
Manufacturer Marshall, Sons & Co.
Number built 34 (total)
Specifications
Weight 27 t
Length 9.7 m (31 ft 11 in)
Width 2.5 m (8 ft 1 in)
Height 2.64 m (8 ft 8 in)
Crew 4: commander, driver, mechanic, machine gunner; up to 30 men could be carried.
Armour 10 mm
Main
armament
 2 x 0.303 in machine guns
Secondary
armament
 none, but loopholes for 16 soldiers
Engine Ricardo 6-cylinder petrol
150 horsepower (110 kW)
Power/weight 5.6 horsepower per tonne (4.2 kW/t)
Suspension unsprung
Operational
range
 20 miles (32 km)
Speed 6.9 km/h (4.3 mph)

The Mark IX tank was a British armoured fighting vehicle from the First World War. It was the world's first specialised armoured personnel carrier (APC).

Development

During the first actions with tanks, it became clear that infantry often could not keep up with the tanks; not because soldiers were too slow—the early tanks themselves could only move at a walking pace—but because soldiers on foot remained vulnerable to machine gun fire, though tanks had been invented to solve that problem. On many occasions, positions gained at great cost were immediately lost for lack of infantry to consolidate. It was thought this problem might be solved by cramming a few infantry soldiers into each tank, but the atmosphere inside was of so poor quality that the soldiers became ill—losing consciousness or, when exposed to fresh air again, being incapacitated for about an hour while recovering from the noxious fumes inside the tank.

In mid-1917, at the same time another 'carrier' tank, the Gun Carrier Mark I was under development, Lieutenant G.R. Rackham was ordered to design an armoured vehicle specifically for troop transport. Design was complicated by a demand that the vehicle could be fitted with sponsons, converting it into a more modern battle tank than the Mark V, in case the Mark VIII tank design proved a failure and the type was still designated as a tank, a 'Mark IX' to succeed the Mark VIII but that requirement was soon dropped.

Prototype construction and production

In September 1917 Armstrong, Whitworth & Co. in Newcastle-upon-Tyne began constructing two prototypes of a the pure transport vehicle that would become the Mark IX, which could also serve as a supply tank. Prototypes were approved the following year, at a time when it had become clear that a possible alternative, the stretched Mark V* tank, was unsuited for infantry transport. Two hundred Mark IXs were ordered from the tractor manufacturer Marshall, Sons & Co. of Gainsborough, Lincolnshire but by the end of the Great War only three had been finished, out of a total production of thirty-four. A specially-designed sledge developed by the tank workshop in France, that allowed an additional 10 long tons (10 t) of stores to be hauled, was tried. This held the promise that the load carrying capacity of the Mark IX could be doubled but while this worked after a fashion, the Mark IX, even without a sledge, proved underpowered, slow, cumbersome to drive and difficult to handle.

Description

Internal arrangement of a Mark IX tank

As there was no time for a completely new design, the Mark IX was based on the Mark V, with the hull lengthened to 9.73 m. The 150 hp Ricardo engine was moved to the front, the gearbox to the back and the suspension girders left out entirely. This created an inner space 4 metres long and 2.45 m wide, enough room for thirty (officially even fifty) soldiers or ten tons of cargo. To ensure sufficient stiffness for the chassis, the floor was reinforced by heavy transverse girders. The infantry inside had to contend with the control rods for the gears running along the roof and the drive shaft through the middle. No seats were provided for them.

The crew proper consisted of a driver sitting on the left and a commander sitting to the right of him (the first time in a British tank making this concession to the prevailing traffic conditions in France), a mechanic, and a machine gunner who could man a gun in a hatch at the rear. A second machine gun was fitted in the front. Along each side of the hull were eight loopholes, through which the soldiers could fire their rifles. This provision arguably qualifies the Mark IX as the world's first track-laying infantry fighting vehicle.) Four of the in total sixteen loopholes were in the four oval doors (two to each side) through which soldiers could embark and disembark.

Despite the use of thinner—0.39 inches (10 mm)—armour, the operational weight was still 27 long tons (27 t) and the speed only 4 mph (6.4 km/h). The tank could also carry supplies in a tray on the roof behind the commander's armoured observation turret (being the highest point at 8.7 feet (2.64 m)), while towing up to three loaded sledges. Rackham tried to improve internal conditions by putting a large silencer on the roof together with ventilation fans; but there was still no separate engine compartment and it is therefore questionable whether the project achieved the goal of a vehicle capable of delivering a squad of infantry in fighting condition, even given the severely limited operational range of the Mark IX.

Operational history and project

The Mark IX tank at The Tank Museum

The Mark IX's were used for some years after the war. The type - named The Pig after the front track silhouette that gave a snout-like appearance - was used as the basis of two conversions: one of the first three built was used as an armoured ambulance, another was rebuilt as an amphibious tank by the staff of the test base at Dollis Hill.

Already a bulky vehicle its displacement was improved by fitting drums at the front and sides. Long wooden boards were attached to the track links but at one side of the board only; as they reached the curve of the track they would project, acting as paddles. Pictures were made of a floating tank in Hendon Reservoir at 11 November 1918, the day of the Armistice. According to oral tradition this vehicle was named The Duck but there are doubts as to its veracity.

The last surviving Mark IX now resides at The Tank Museum, Bovington.

References

    Wikimedia Commons has media related to Mark IX tank.
    This article is issued from Wikipedia - version of the Sunday, May 01, 2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.