The development of Tanks in World War I began as a solution to the stalemate which trench warfare had brought to the western front. The first prototype of the Mark I tank was tested for the British Army on 8 September 1915. Although initially termed "land ships" by the British Army, initial vehicles were referred to as "water-carriers" (then shortened to "tanks") to preserve secrecy.
While the British took the lead in tank development, the French were not far behind and fielded their first tanks in 1917. The Germans, on the other hand, were slower to develop tanks, concentrating on anti-tank weapons.
Initial results were mixed, with reliability problems causing considerable attrition rates during combat deployment and transit. The heavily bombed-out terrain was relatively impassable, and only highly mobile tanks such as the Mark I and FTs performed reasonably well. The Mark I's rhomboid shape meant it could navigate larger obstacles, especially long trenches, better than many modern armoured fighting vehicles.
The tank would eventually make the trench warfare of World War I obsolete, and the thousands of tanks fielded by French and British forces made a significant contribution to the war effort.
From 1904 to 1909, David Roberts, the engineer and managing director of Hornsby & Sons of Grantham, built a series of tractors using his patented 'chain-track' which were put through their paces by the British Army, a (small) section of which wanted to evaluate artillery tractors. At one point, in 1908, a perceptive officer remarked to Roberts that he should design a new machine with armour, capable of carrying its own gun. But, disheartened by years of ultimately fruitless tinkering for the Army, Roberts failed to take up the idea.
An Austrian engineer, Gunther Burstyn, inspired by Holt tractors, designed a tracked armoured vehicle in 1911 carrying a light gun in a rotating turret; equipped also with hinged 'arms', two in front and two at the rear, carrying wheels on the ends to assist with obstacles and trenches, it was a very forward-looking design, if rather small. The Austrian government said it would be interested in evaluating it if Burstyn could secure commercial backing to produce a prototype. Lacking the requisite contacts, he let it drop. An approach to the German government was similarly fruitless.
In 1912, A South Australian, Lancelot De Mole, submitted a proposal to the British War Office for a "chain-rail vehicle which could be easily steered and carry heavy loads over rough ground and trenches". De Mole made several more proposals to the War Office after 1912, in 1914 and 1916, with a culminating proposal in late 1917, accompanied by a huge one-eighth scale model, yet all fell on substantially deaf ears. De Mole's proposal already had the climbing face, so typical of the later WWI British tanks, but it is unknown whether there was some connection. Inquiries from the government of Australia, after the war, yielded polite responses that Mr De Mole's ideas had unfortunately been too advanced for the time to be properly recognised at their just value. The Commission on Awards to Inventors in 1919, which adjudicated all the competing claims to the development of the tank, recognised the brilliance of De Mole's design, even considering that it was superior to the machines actually developed, but due to its narrow remit, could only make a payment of £987 to De Mole to cover his expenses. As an aside, De Mole noted in 1919 that he was urged by friends before the war to approach the Germans with his design, but declined to do so for patriotic reasons.
Before World War I, motorised vehicles were still relatively uncommon, and their use on the battlefield was initially limited, especially of heavier vehicles. Armoured cars soon became more commonplace with most belligerents, especially in more open terrain. In fact on 23 August 1914 the French Colonel Estienne, later a major proponent of tanks, declared: Messieurs, la victoire appartiendra dans cette guerre à celui des deux belligérants qui parviendra le premier à placer un canon de 75 sur une voiture capable de se mouvoir en tout terrain ("Gentlemen, the victory will belong, in this war, to the one of the two belligerents who will be the first to succeed in mounting a 75 mm gun on a vehicle capable of moving in all types of terrain").
Armoured cars did indeed prove useful in open land such as in deserts, but were not very good at crossing obstacles (e.g. trenches, barriers) or in more challenging terrain. The other issue was that it was very hard to add much protection or armament.
The main limitation was the wheels, which gave a high ground pressure for the vehicle's weight. This could be solved by adding more wheels, but unless they also were driven, the effect was to reduce traction on the powered wheels. Driving extra wheels meant more drive train weight; in turn requiring a larger and heavier engine to maintain performance. Even worse, none of this extra weight was put into an improvement of armour or armament carried, and the vehicles were still incapable of crossing very rough terrain.
The invention of caterpillar tracks offered a new solution to the problem. The tracks spread the weight of the vehicles over a much greater area, which was all used for traction to move the vehicle. The limitation on armour and firepower was no longer ground pressure but the power and weight of the power-plant.
The remaining issue was how to utilise and configure a vehicle, which would be figured out first by the Landship Committee and Inventions Committee. A variety of other concepts would be combined, such as special steel for armour, a climbing face for the tracks, and weapons mounted in rotating turrets.
But before this could happen some individual would have to set the entire process into motion. This person was to be Major Ernest Dunlop Swinton, British official war correspondent serving in France in 1914. Swinton recounts in his book Eyewitness how he first got the sudden idea to build a tank on 19 October 1914, while driving a car in northern France. It is known however that he in July 1914 received a letter from a friend, the South-African engineer Hugh Merriot, asking his attention for the fact that armoured tractors might be very useful in warfare. November 1914 Swinton suggested the idea of an armoured tracked vehicle to the military authorities, by sending a proposal to Lieutenant-Colonel Maurice Hankey. Hankey in turn tried to interest Lord Kitchener in the idea; when this failed he sent in December a memorandum to the Committee of Imperial Defence, of which he was himself the secretary; First Lord of the Admiralty Winston Churchill was one of the members. Hankey proposed to build a gigantic steel roller, pushed by tracked tractors, to shield the advancing infantry. Churchill in turn on 5 January wrote a note to Prime Minister Herbert Asquith, in which he warned that the Germans might any moment introduce a comparable system. A worried Asquith now ordered Kitchener to form the Inventions Committee headed by General Scott-Moncrieff to study the development of armoured vehicles; this committee concluded however in February 1915 that such vehicles were wholly impractical and advised not to develop any.
At first protecting heavy gun tractors with armour appeared the most promising line of development. Alternative early 'big wheel' designs on the lines of the Russian Czar tank of 1915 were soon understood to be impractical. However, adapting the existing Holt Company caterpillar designs — the only robust tracked tractors available in 1915 — into a fighting machine, as France, Germany and the United States did, was decided against as Holt indicated to be unable to deliver a sufficient number for extended mass production. While armour and weapon systems were easy to acquire, other existing caterpillar and suspension units were too weak and existing engines were notably underpowered for the armoured behemoths that the designers had in mind. The Killen-Strait tractor with three tracks was used for the first experiments in June but was much too small to be developed further. The large British Pedrail monotrack vehicle proved to be unsuitable. Trials to couple two small American Bullock tractors failed. There also were considerable differences of opinion between the several committee members. Col R.E.B. Crompton, a veteran military engineer and electrical pioneer, drafted numerous designs with Lucien Legros for armoured troop carrying vehicles and gun-armed vehicles, to have used either Bullock tracks or variants of the Pedrail. At the same time, Lt Robert Macfie, of the RNAS, and Albert Nesfield, an Ealing-based engineer, devised a number of armoured tracked vehicles, which incorporated an angled front 'climbing face' to the tracks. The two men were to fall out bitterly as their plans came to nought, Macfie in particular pursuing a vendetta against the other members of the Landships Committee after the war.
To resolve the threatened dissipation of effort, it was ordered in late July that a contract was to be placed with William Foster & Co. Ltd, a company having done some prewar design work on heavy tractors and known to Churchill from an earlier experiment with a trench-crossing supply vehicle, to produce a proof-of-concept vehicle with two tracks, based on a lengthened Bullock tractor chassis. Construction work began three weeks later.
Fosters of Lincoln built the 14 ton "Little Willie", which first ran on 8 September. Powered by a 105 hp (78 kW) Daimler engine, the ten-foot high armoured box was initially fitted with a low Bullock caterpillar. A rotating top turret was planned with a 40 mm gun but abandoned due to weight problems, leaving the final vehicle unarmed and little more than a test-bed for the difficult track system. Difficulties with the commercial tracks led to Tritton designing a completely new track system different from, and vastly more robust than, any other system then in use. The next design by Lieutenant Walter Gordon Wilson added a larger track frame to the hull of "Little Willie". In order to achieve the demanded gap clearance a rhomboidal shape was chosen—stretching the form to improve the track footprint and climbing capacity. To keep a low centre of gravity the rotating turret design was dropped in favour of sponsons on the sides of the hull fitted with naval 6-pounder 57 mm guns. A final specification was agreed on in late September for trials in early 1916, and the resulting 30 ton "Big Willie" (later called "Mother") together with "Little Willie" underwent trials at Hatfield Park on 29 January and 2 February. Attendees at the second trial included Lord Kitchener, Lloyd George, Reginald McKenna and other political luminaries. On 12 February an initial order for 100 "Mother" type vehicles was made, later expanded to 150.
Although landship was a natural term coming from an Admiralty committee, it was considered too descriptive and could give away British intentions. The committee therefore looked for an appropriate code term for the vehicles. Factory workers assembling the vehicles had been told they were producing "mobile water tanks" for desert warfare in Mesopotamia. Water Container was therefore considered but rejected because the committee would inevitably be known as the WC Committee (WC meaning water closet was a common British term for a toilet). The term tank, as in water tank, was in December 1915 finally accepted as its official designation. From then on, the term "tank" was established among British and also German soldiers, but rejected by the French. While in German Tank specifically refers to the World War I type (as opposed to modern Panzer), in English, Russian and other languages the name even for contemporary armoured vehicles is still based on the word tank.
Legend has it that after completion, the tanks were shipped to France in large wooden crates. For secrecy and in order to not arouse any curiosity, the crates and the tanks themselves were then each labelled with a destination in Russian for Petrograd. In fact the tanks were never shipped in crates: the inscription in cyrillic Russian was applied on the hull for their transport from the factory to the first training centre at Thetford.
The first fifty had been delivered to France on 30 August. They were 'male' or 'female', depending upon whether their armament was the 57 mm gun or only multiple smaller Hotchkiss or Vickers machine guns. The crew was eight, four of whom were needed to handle the steering and drive gears. The tanks were capable of 6 km/h (4 mph), matching the speed of marching infantry with whom they were to be integrated to aid in the destruction of enemy machine guns.
After the war, The Royal Commission on Awards to Inventors decided that the inventors of the Tank were Sir William Tritton, managing director of Fosters and Major Walter Gordon Wilson.
The Mark I's were capable of performing on the real battlefield of WWI, one of the most difficult battlefield terrains ever. They did have reliability problems, but when they were working they could cross trenches or craters of 9 feet (2.7 m) and drive right through barbed wire. It was still common for them to get stuck, especially in larger bomb craters, but overall the rhomboid shape allowed for extreme terrain mobility.
Most WWI tanks could travel only at about a walking pace at best. Their steel armour could stop small arms fire and fragments from high-explosive artillery shells. However they were vulnerable to a direct hit from artillery and mortar shells. The environment inside was extremely unpleasant; the atmosphere was contaminated with poisonous carbon monoxide, fuel and oil vapours from the engine and cordite fumes from the weapons as ventilation was inadequate. Temperatures inside could reach 50°C (122°F). Entire crews lost consciousness or became violently sick when again exposed to fresh air.
To counter the fumes inside and the danger of bullet splash or fragments and rivets knocked off the inside of the hull, the crew wore helmets with goggles and chainmail masks. 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 a larger purpose-made anti-tank rifle, and also a Geballte Ladung ("Bunched Charge")—several regular stick grenades bundled together for a much bigger explosion.
Engine power was a primary limitation on the tanks; the roughly one hundred horsepower engines gave a power-to-weight ratio of 3.3 hp/ton (2.5 kW/ton). By the end of the 20th century, power-to-weight ratios exceeded 20 hp/ton (15 kW/ton).
Many feel that because the British Commander Field Marshal Douglas Haig was himself a horse cavalryman, his command failed to appreciate the value of tanks. In fact, horse cavalry doctrine in World War I was to "follow up a breakthrough with harassing attacks in the rear", but there were no breakthroughs on the Western Front until the tanks came along. Despite these supposed views of Haig, he made an order for 1,000 tanks shortly after the failure at the Somme and always remained firmly in favour of further production.
France at the same time developed its own tracked AFVs, but the situation there was very different. In Britain a single committee had coordinated design, and had to overcome the initial resistance of the Army, while the major industries remained passive. Almost all production effort was thus concentrated into the Mark I and its direct successors, all very similar in shape. In France, on the other hand, there were multiple and conflicting lines of development which were badly integrated, resulting in three major and quite disparate production types. A major arms producer, Schneider, took the lead in January 1915 and tried to build a first armoured vehicle based on the Baby Holt tractor but initially the development process was slow until in July they received political, even presidential, support by combining their project with that of a mechanical wire cutter devised by engineer and politician Jean-Louis Bréton. In December 1915, the influential Colonel Estienne made the Supreme Command very enthusiastic about the idea of creating an armoured force based on these vehicles; strong Army support for tanks would be a constant during the decades to come. Already in January and February 1916 quite substantial orders were made, at that moment with a total number of 800 much larger than the British ones.
Army enthusiasm and haste would have its immediate drawbacks however. As a result of the involvement of inexperienced army officers ordered to devise a new tank based on the larger 75 hp Holt chassis in a very short period of time, the first French tanks were poorly designed with respect to the need to cross trenches and did not take the sponson-mounting route of the British tanks. The first, the Char Schneider CA equipped with a short 75 mm howitzer, had poor mobility due to a short track length combined with a hull that overhung front and rear. It was unreliable as well; a maximum of only about 130 of the 400 built were ever operational at the same time. Then industrial rivalry began to play a detrimental role: it created the heavy Char St Chamond, a parallel development not ordered by the Army but approved by government through industrial lobby, which mounted much more impressive weaponry — its 75 mm was the most powerful gun fielded by any operational tank up till 1941 — but also combined many of the Schneider CA's faults with an even larger overhanging body. Its innovative petro-electrical transmission, while allowing for easy steering, was insufficiently developed and led to a large number of breakdowns.
But industrial initiative also led to swift advances. The car industry, already used to vehicle mass production and having much more experience in vehicle layout, in 1916 designed the first practical light tanks, a class largely neglected by the British. It would be Renault's excellent small tank design the FT-17 (which won out over a Peugeot model), incorporating a proper climbing face for the tracks, that was the first tank to incorporate a top-mounted turret with a full rotation. In fact the FT was in many respects the first truly 'modern' tank having a layout that has been followed by almost all designs ever since: driver at the front; main armament in a fully-rotating turret on top; engine at the rear. Previous models had been "box tanks", with a single crowded space combining the role of engine room, fighting compartment, ammunition stock and driver's cabin. The FT-17 would have the largest production run of any tank of the war, with over 3700 built more numerous than all British tanks combined. That this would happen was at first far from certain; some in the French army lobbied for the alternative mass production of super-heavy tanks. Much design effort was put in this line of development resulting in the gigantic Char 2C, the most complex and technologically advanced tank of its day. Its very complexity ensured it being produced too late to participate in WWI and in the very small number of just ten, but it would be the first tank with a three-man turret; the heaviest to enter service until late in WWII and still the largest ever operational.
French production at first lagged behind the British. After August 1916 however, British tank manufacture was temporarily halted to wait for better designs, allowing the French to overtake their allies in numbers. When the French used tanks for the first time on 16 April 1917, during the Nivelle Offensive, they had four times more tanks available. But that would not last long as the offensive was a major failure; the Schneiders and chars St Chamond (which saw their first action on 5 May) didn't have the ability to cross trenches as the British could and were torn to pieces by concentrated German artillery fire.
The first really successful use of tanks came in the Battle of Cambrai in 1917. British Colonel J.F.C. Fuller, chief of staff of the Tank Corps, planned the battle. The tanks made an unprecedented breakthrough but, as ever on the Western front, the opportunity was not exploited. Ironically, it was the soon-to-be-supplanted horse cavalry that had been assigned the task of following up the motorised tank attack.
Tanks became more effective as the lesson of the early tanks was absorbed. The British produced the Mark IV in 1917. Similar to the early Marks in appearance, its construction was considered to produce a more reliable machine, the long-barrelled naval guns were shortened (the barrels of the earlier, longer, guns, being prone to digging in the mud when negotiating obstacles) and armour was increased just enough to defeat the standard German armour-piercing bullet.
The continued need for four men to drive the tank was solved with the Mark V in 1918. Also in 1918 the French produced the Renault FT-17, the result of a co-operation between Estienne and Louis Renault. As mentioned before, it had the innovative turret position, and was operated by two men. At just 8 tons it was half the weight of the Medium A Whippet but the version with the cannon had more firepower. It was conceived for mass production, and the FT would become the most produced tank of WWI by a wide margin with over 4,500 made, being also used and produced by the Americans.
The German General Staff did not have enthusiasm for the tank, but allowed the development of anti-tank weapons. Regardless, development of a German tank was underway. The only project to be produced and fielded was the A7V, although only fifteen A7Vs were built. The majority of the roughly hundred or so tanks fielded by Germany were captured British and French vehicles. A7Vs were captured by the Allies, but they were not used, and most ended up being scrapped.
Fuller's Plan 1919 involving massive use of tanks for an offensive, was never used because the blockade of Germany and the entry of the US brought an end to the war. The plan itself would become the inspiration for German blitzkrieg tactics in World War II. As a military planner and later journalist, Fuller continued to develop his doctrine of using tanks supported by infantry to break through enemy lines to attack communications in the rear.
Finally, in a preview of later developments, the British developed the Whippet. This tank was specifically designed to exploit breaches in the enemy front. The Whippet was faster than most other tanks, although it carried only machinegun armament. Postwar tank designs would reflect this trend towards greater tactical mobility.