British heavy tanks of World War I

The British Mark I was a tracked vehicle developed by the British Army during the First World War, and the world's first combat tank. Born of the need to break the domination of trenches and machine guns over the battlefields of the Western Front, it was the first vehicle to be named "tank", a name chosen as an expedient to maintain secrecy and to disguise its true purpose. It was developed to be able to cross trenches, resist small-arms fire, travel over difficult terrain, carry supplies, and to capture fortified enemy positions. It is regarded as successful in many respects, but suffered from many problems owing to its primitive nature.

The Mark I entered service in August 1916, and was first used in action on the morning of 15 September 1916 during the Battle of Flers-Courcelette, part of the Somme Offensive. With the exception of the few interim Mark II and Mark III tanks, it was followed by the largely similar Mark IV, which first saw combat in June 1917. The Mark IV was used en masse (about 460 tanks) at the Battle of Cambrai in November 1917 The Mark V, with its much improved transmission, entered service in mid-1918.

Development
The Mark I was a development of Little Willie, the experimental tank built for the Landships Committee by Lieutenant Walter Wilson and William Tritton in the summer of 1915. It was designed by Wilson in response to problems with tracks and trench-crossing ability discovered during the development of Little Willie. A gun turret above the hull would have made the centre of gravity too high when climbing a German trench parapet (which were typically four feet high), so the tracks were arranged in a rhomboidal form around the hull and the guns were put in sponsons on the sides of the tank. The reworked design was also able to meet the Army requirement to be able to cross an 8 ft wide trench.

A mockup of Wilson's idea was shown to the Landships Committee when they viewed the demonstration of Little Willie. At about this time, the Army's General Staff was persuaded to become involved and supplied representatives to the Committee. Through these contacts Army requirements for armour and armament made their way into the design. The prototype Mark I, ready in December 1915, was called "Mother" (previous names having been "The Wilson Machine", "Big Willie", and "His Majesty's Land Ship Centipede"). Mother was successfully demonstrated to the Landships Committee in early 1916; it was run around a course simulating the front including trenches, parapets, craters and barbed wire obstacles. The demonstration was repeated on 2 February before the cabinet ministers and senior members of the Army. Kitchener, the Secretary of State for War, was sceptical but the rest were impressed. Lloyd George, at the time Minister of Munitions, arranged for his Ministry to be responsible for tank production.

The Landships Committee was re-constituted as the "Tank Supply Committee" under the chairmanship of Albert Stern; Ernest Swinton, who had promoted the idea of the tank from the Army angle was also a member. General Haig sent a staff officer Hugh Elles to act as his liaison to the Supply Committee. Swinton would become the head of the new arm, and Elles the commander of the tanks in France.

The first order for tanks was placed on 12 February 1916. Fosters were to build 25 and Metropolitan Carriage and Wagon 75. One hundred and fifty Mark Is were built.

Description
The Mark I was a rhomboid vehicle with a low centre of gravity and long track length, able to negotiate broken ground and cross trenches. Main armament was carried in sponsons on the hull sides.

The hull was undivided internally; the crew shared the same space as the engine. The environment inside was extremely unpleasant; since ventilation was inadequate, the atmosphere was contaminated with poisonous carbon monoxide, fuel and oil vapours from the engine, and cordite fumes from the weapons. Temperatures inside could reach 50 °C (122 °F). Entire crews lost consciousness inside the tank or, sometimes, collapsed when again exposed to fresh air.

To counter the danger of bullet splash or fragments knocked off the inside of the hull, crews were issued with leather-and-chainmail masks and a leather helmet was also issued, to protect the head against projections inside the tank. Gas masks were standard issue as well, as they were to all soldiers at this point in the war (see Chemical warfare). The side armour of 8 mm initially made them largely immune to small arms fire, but could be penetrated by the recently developed armour-piercing K bullets. There was also the danger of being overrun by infantry and attacked with grenades. The next generation had thicker armour, making them nearly immune to the K bullets. In response, the Germans developed the 13.2 mm Mauser anti-tank rifle, and also a Geballte Ladung ("Bunched Charge") – several regular stick grenades bundled together for a much bigger explosion.

A direct hit by an artillery or mortar shell could cause the fuel tanks (which were placed high in the front horns of the track frames either side of the drivers' area, to allow gravity feed) to burst open. Incinerated crews were removed by special Salvage Companies, who also salvaged damaged tanks.

Steering was difficult, controlled by varying the speed of the two tracks. Four of the crew, two drivers (one of whom also acted as commander; he operated the brakes, the other the primary gearbox) and two "gearsmen" (one for the secondary gears of each track) were needed to control direction and speed, the latter never more than a walking pace. As the noise inside was deafening, the driver, after setting the primary gear box, communicated with the gearsmen with hand signals, first getting their attention by hitting the engine block with a heavy spanner. For slight turns, the driver could use the steering tail: an enormous contraption dragged behind the tank consisting of two large wheels, each of which could be blocked by pulling a steel cable causing the whole vehicle to slide in the same direction. If the engine stalled, the gearsmen would use the starting handle – a large crank between the engine and the gearbox. Many of these vehicles broke down in the heat of battle making them an easy target for German gunners. There was no wireless (radio); communication with command posts was by means of two pigeons, which had their own small exit hatch in the sponsons, or by runners. Because of the noise and vibration, early experiments had shown that radios were impractical, therefore lamps, flags, semaphore, coloured discs, and the carrier pigeons were part of the standard equipment of the various marks.

During the First World War, British propaganda made frequent use of tanks, portraying them as a wonder weapon that would quickly win the war. They were featured in films and popular songs.

Variants
The first tanks were known as the Mark I after the subsequent designs were introduced. Mark Is armed with two 6 pounder guns and three 8 mm Hotchkiss machine guns were called "Male" tanks, and those with four Vickers machine guns and one Hotchkiss, were called "Female". Swinton is credited with inventing the terms.

To aid steering, a pair of large wheels were added behind the tank. These were not as effective as hoped and were subsequently dropped.

The subsequent Mark II, III, IV, and V, and later tanks, all bear a strong resemblance to their "Mother".

Mark I

 * Crew: 8
 * Combat Weight
 * Male: 28 tons (28.4 tonne)
 * Female: 27 tons (27.4 tonne)
 * Armour: .23–.47 in (6–12 mm)
 * Armament
 * Male: two 6-pounder QF, three 8 mm Hotchkiss Machine Guns
 * Female: four .303 Vickers Machine Guns, one 8 mm Hotchkiss Machine Gun

The Gun Carrier Mark I was a separate design, intended to carry a field gun or howitzer that could be fired from the vehicle. In service it was mostly used for carrying supplies and ammunition. Forty-eight were built.

Initial production of the Mark I was to be by Fosters and Metropolitan: 25 from Fosters and 75 from Metropolitan, who had greater capacity. Metropolitan set up production under their Oldbury Wagon and Carriage Company and then received an order for a further 50 so that the Army would be able to raise 6 tank companies of 25 tanks each. As there were not enough 6-pounder guns available for all 150 tanks, it was decided to equip half of them with only machine guns. A new sponson design with two Vickers machine guns in rotating shields was produced.

Mark II
The Mark II incorporated minor improvements over the Mark I. With the Army declaring the Mark I still insufficiently developed for use, the Mark II (for which orders were first placed in July) would continue to be built but it would be used for training only. As they were only to be used as training tanks they were supposedly clad in unhardened steel, though some doubt was cast on this claim in early 1917. Initially twenty were shipped to France and twenty-five remained at the training ground at Wool, Dorset in Britain; the remaining five were kept for use as test vehicles. As the promised Mark IV tanks had not arrived by early 1917 it was decided, despite the protestations of Stern (see below), to ship the twenty-five training vehicles in Britain to France, where they joined the other twenty Mark IIs and fifteen Mark Is at the Battle of Arras in April 1917. The Germans were able to pierce the armour of both the Mark I and Mark II tanks at Arras with their armour-piercing machine gun ammunition.

The Mark II was built from December 1916 to January 1917 by Foster & Co and Metropolitan (25 Male and 25 Female respectively).

Five Mark IIs from were taken for experiments on improved powerplants and transmission. They were provided to firms to show what improvements they could make over the Mark I system in an open competition. In the demonstrations held on March 1917 only three of them were able to compete alongside Mother which had been fitted with a Daimler petrol-electric system. Wilson's epicyclic gear system that replaced the secondary gear and the gearsmen was clearly superior and adopted in later designs.

Surviving parts from Mark II no. 799 (D26), including tracks and gunshields, can be seen at the Musée Jean et Denise Letaille, Bullecourt.

Mark III
The Mark III was a training tank, which used Lewis machine guns and a smaller sponson for the females. Fifty were built. It was originally intended that the Mark III have all the proposed new design features of the Mark IV. This is why there were two distinct training types, the Mark II being little more than a slightly improved Mark I. Development of the new features was so slow however, that the change from the Mark II was very gradual. The last two Mark IIIs were melted down in the Second World War. They did not see action overseas.

Mark IV
Mark IV was an up-armoured version of the Mark I that went into production in May 1917. Fundamental mechanical improvements had originally been intended, but had to be postponed, the main change consisting in the switch to shorter-barrelled 6-pounder guns. It had all fuel stored in a single external tank (located between the rear track horns) in an attempt to improve crew safety. The sponsons could be pushed in to reduce the width of the tank for rail transportation. Rails on the roof carried an unditching beam. A total of 1,220 were built: 420 males, 595 females and 205 tank tenders, which were supply tanks.

The Mark IV was used successfully at the Messines Ridge in June 1917, where they outpaced the infantry on dry ground, but in the Third Ypres of July and August they found the swampy ground difficult and were of little use. About 432 Mark IV tanks were used during the Battle of Cambrai in November 1917.

The first tank-to-tank battle was between Mk IV tanks and German A7Vs in the Second Battle of Villers-Bretonneux in April 1918.

Mark V series
The Mark V was first intended to be a completely new design of tank, of which a wooden mock-up had been finished. However, when the new engine and transmission originally destined for the Mark IV became available in December 1917, the first, more advanced Mark V design was abandoned for fear of disrupting the production run. The designation "Mark V" was switched to an improved version of the Mark IV, equipped with the new systems. The original design of the Mark IV was to be a large improvement on the Mark III but had been scaled back to be a mild improvement because of technical delays. The Mark V thus turned out very similar to the original design of the Mark IV – i.e. a greatly modified Mark III.

Four hundred were built, 200 each of Males and Females. Several were converted to Hermaphrodites (also known as "Composites") by fitting one male and one female sponson so that each tank had a 6-pounder. This measure was intended to ensure that female tanks would not be outgunned when faced with captured British male tanks in German use or the Germans' own A7V.

The Mark V was first used in the Battle of Hamel on 4 July 1918 when 60 tanks contributed to a successful assault on the German lines by Australian units. It took part in eight further major engagements during the War. A number saw service in the Allied intervention in the Russian Civil War on the White Russian side. Most were subsequently captured and used by the Red Army in the Russian Civil War. Four were retained by Estonian forces, and two by Latvia.

Mark VI
The Mark VI was one of a pair of related projects to develop the tank initiated in late 1916. The Mark V would be the application of as many advanced features as could be managed on the Mark I hull design and the Mark VI would be a complete break with the Mark I hull. The Mark V would not be built as such, because of the delays with the Mark IV and it would be a different Mark V that was built. The Mark VI project design had a completely new hull – taller and with rounded track paths. The single main gun was in the front of the hull. It did not progress past the stage of a wooden mock-up; the project was cancelled in December 1917 in order that a tank co-developed with the US (the Mark VIII) could go forward.

Mark VII
Mark Knothe, the Technical Liaison Officer between Stern, Elles and Anley, contributed to the development of the tank, designing a longer Mark I with Williams-Janney hydraulic transmission; one of the Mark IIs used as test vehicles had used a hydraulic transmission. In October 1917 Brown Brothers in Edinburgh were granted a contract to develop this line of research further. In July 1918 the prototype was ready. Its drive system was very complex. The 150 hp Ricardo engine drove into Variable Speed Gear Ltd. pumps that in turn powered two hydraulic motors, moving one track each by means of several chains. To ward off the obvious danger of overheating there were many fans, louvres and radiators. Steering was easy and gradual however and the version was taken into production to equip one tank battalion. Three had been built, and only one delivered out of an order for 74 when war ended. It was passed over in favour over the V** which was ordered at the same time. The hull was slightly lengthened in comparison with the Mark V. No Mark VIIs survive.

Mark VIII


When Stern was removed from his post following disagreements with the War Office, he was sidelined by appointment to a new department to work on a cooperative design between the Allies – assembly in France, hulls, guns and their ammunition from the UK and other components (principally the engines) from the USA. American involvement in the development of the tank design led to the Mark VIII, also known as "Liberty" or Anglo-American tank (though initially the French were partially involved).

The engine was compartmentalised from the crew, and the turret structure included forward and rear firing machine guns. Of a planned (shared production) of 1,500 each, a single British prototype was finished by the end of the war. The British built only 24 in total, the Americans completed 100 between September 1918 and 1920, at the Rock Island Arsenal, at a cost of $35,000 [£8,750] apiece ($430,000 [£226,000] in 2006). About 40 hulls for the U.S Liberty were produced by the Manchester Tank Syndicate, 11 British Type Mark VIII by the North British Locomotive Co.

They were used and upgraded until the 1930s when given to Canada for training; some M1917s  were sold to the Canadians at nominal scrap value. The tank itself was over 34 feet (10 m) long, and there had been an even longer 44 foot (13 m) version planned but never made (the Mark VIII*). The tank was outdated by the 1930s due to its speed (under 6 mph/10 km/h) and armour (16–6 mm) but it did have one of the longest independent trench crossing capabilities of any armoured fighting vehicle (AFV) ever made. Modern main battle tanks and AFVs rely on bridge laying tanks for crossing large deep trenches.
 * Crew: 12 (later 10)
 * Weight 37 tons (37.6 tonnes)
 * Length/Height/Width : 34 ft 2 in by 10 ft 3 in by 12 ft 4 in (10.4 m by 3.1 m by 3.8 m) (Mark VIII* length 44 ft/13.4 m)
 * Engine: Ricardo 330 hp petrol (UK), Liberty V12 300 hp (U.S.).

Mark IX
The Mark IX was a troop carrier or infantry supply vehicle – among the first tracked armoured personnel carrier not counting experiments with the lengthened Mk V's. Thirty-four were built out of an order for 200.

Mark X
Paper only project to improve the Mark V, originally known as Mark V***. This was basically a contingency plan in case the Mark VIII project would fail (if so a production of 2000 was foreseen for 1919), trying to produce a tank with as many parts of the Mark V as possible but with improved manoeuvrability and crew comfort.

Combat history
The first tanks were added, as a "Heavy Branch", to the Machine Gun Corps until a separate Tank Corps was formed on 28 July 1917 by Royal Warrant. A small number of Mark I tanks took part in the Battle of the Somme during the Battle of Flers-Courcelette in September 1916. They were used to cut through barbed wire to clear the way for infantry, and were even driven through houses to destroy machine gunner's emplacements. Although many broke down or became stuck, almost a third that attacked made it across no man's land, and their effect on the enemy was noted, leading to a request by the British C-in-C Douglas Haig for a thousand more. This came as a surprise: William Tritton had already started the development of a heavier tank: the Flying Elephant. Unfortunately for the Allies, it also gave the Germans time to develop a specifically designed anti-tank weapon for the infantry, an armour-piercing 7.92 mm K bullet.

Eight Mk I tanks were used against Turkish forces in the Second Battle of Gaza in April 1917 during the Sinai and Palestine Campaign. With its three destroyed tanks replaced by Mk IVs, the tank company fought at the Third Battle of Gaza.

During the Battle of Amiens in August 1918, several hundred Mark V tanks, along with the new Whippet and Mk V* tanks, penetrated the German lines in a foretaste of modern armoured warfare.

Mark V tanks captured by the Red Army from the White Army in the course of the Russian Civil War were used in 1921 during the Red Army invasion of Georgia and contributed to the Soviet victory in the battle for Tbilisi.

In 1945, Allied troops came across two badly damaged Mk V tanks in Berlin. Photographic evidence indicates that these were survivors of the Russian Civil War and had previously been displayed in Smolensk before being brought back to Berlin after the German invasion of the Soviet Union in 1941. Accounts of their active involvement in the Battle of Berlin have not been verified.

Little Willie
Little Willie survives at the Bovington Tank Museum. It was saved from being scrapped in 1940 on the pretext it was helping to defend Bovington base against possible German attacks. Many other prototypes were melted down during the invasion scare.

Mark I
A single male survives. This is the only surviving Mark I and the world's oldest surviving combat tank. It is part of the collection at the Bovington Tank Museum. It is painted to represent Number 705, C19, Clan Leslie although its identity and wartime history are unknown. There are indications it may have served as a driver-training tank and it has been suggested it is Number 702, which would make it the second Mark I built. Between 1919 and 1970, it was sited in the grounds of Hatfield House to commemorate the fact this was a testing site for tanks during their earliest development.

Mark II
There is a single surviving Mark II Female, F53: The Flying Scotsman, at the Bovington Tank Museum. This tank still has battle damage sustained at the Battle of Arras in April 1917.

Mark IV
Seven Mark IVs survive.
 * A Mark IV Female, F4: Flirt II, which fought at the Battle of Cambrai, is at the Museum of Lincolnshire Life, Lincoln, England, on permanent loan from the Bovington Tank Museum. A local company, William Foster & Co., manufactured the first tanks.
 * A Mark IV Female is preserved at Ashford in Kent. This is one of many that were presented for display to towns and cities in Britain after the war; most were scrapped in the 1920s and 1930s.
 * The Royal Museum of the Army in Brussels has a Male Mark IV tank, the Lodestar III, still in original colours.
 * A Mark IV Female,Grit, is stored at the Australian War Memorial. It was on display in ANZAC Hall at the Australian War Memorial until August 2008. It is now kept at their bulk store in Mitchell, Canberra.
 * In 1999, a Mark IV Female, D51: Deborah, was excavated at the village of Flesquières in France. It had been knocked out by shell-fire at the Battle of Cambrai (1917) and subsequently buried when used to fill a crater. Work is underway on its restoration.
 * A Mark IV Male, Excellent, is displayed at Bovington. After World War I, this tank was presented by the army to HMS Excellent, a Royal Navy shore establishment where some tank crewmen were trained. During World War II, it was made operational again for service with the Home Guard when German invasion threatened in 1940. It is still maintained in working order.
 * Mark IV Female Liberty: displayed at United States Army Ordnance Museum, Aberdeen, Maryland. Originally named Britannia, Renamed Liberty, the tank joined the Ordnance Museum collection in 1919. After decades of exposure to the elements, it is in poor condition, but about to undergo restoration.

Mark V
Eleven Mark Vs survive. The majority are in Russia or Ukraine and are survivors of the tanks sent there to aid the White forces during the Russian Civil War.
 * The Bovington Tank Museum displays a Mark V Male, Number 9199, one of two British World War I tanks still in working order. It was in action at the Battle of Amiens where its commander – Lt. H. A. Whittenbury – was awarded the Military Cross.
 * A Mark V** Female: Ol' Faithful, is also preserved at Bovington.
 * A heavily restored Mark V Male, Devil, survives at the London Imperial War Museum.
 * A Mark V* Male, Number 9591, has since 2010 been part of the collection of the National Armor and Cavalry Museum, Fort Benning, Georgia. Issued to Company A, US 301st Heavy Tank Battalion and knocked out by a single artillery round on September 27, 1918 during the attack against the Hindenburg Line, it was repaired and sent back to the United States. It represents the only surviving exemplar of the Mark V*.
 * A Mark V is at the Kubinka Tank Museum, Russia.
 * A Mark V serves as memorial in Arkhangelsk. This was originally used by British forces during the Allied Intervention in the Russian Civil War.
 * Two preserved Mark Vs, a Male and a Female, form part of an outdoor memorial at Luhansk in Ukraine; two more are in storage.
 * A Mark V Female is at the Kharkiv Historical Museum, Ukraine.

Mark VIII/Liberty

 * A Mark VIII Liberty tank originally at the Aberdeen Proving Ground, Maryland, has in 2010 been transferred to the National Armor and Cavalry Museum at Fort Benning, GA. The vehicle was originally assigned to the American 67th Infantry Regiment (Heavy Tanks) at Fort Benning, GA.
 * A modified Liberty tank is preserved at Fort Meade, Maryland. The tank displayed in the post museum was made in 1920 at Rock Island Arsenal, Illinois. It was assigned to the 301st Tank Battalion (Heavy), later redesignated the 17th Tank Battalion (Heavy).  Throughout most of 1921–1922, Major Dwight D. Eisenhower commanded this unit
 * A British Mark VIII is at Bovington.

Mark IX
A single restored vehicle survives at Bovington.