World War One tanks
The online tank museum
World War One tanks


When and where was the tank first imagined, developed, and their evolution in combat from 1916 to 1918, as well as tactical development during the interwar period.

Part I: Introduction

Early forerunners. Did the idea of a tank really originate during the First World War?

Part II: The Deadly Equation

Pioneering experiments, proposals and doctrines which led to the development of the tank

Part III: The Holt Tractors

How the American Holt caterpillar tractor gave the solution

Part IV: 1916 - First Blood

Early tanks, first engagements, successes and failures

Part V: 1917 - Full Armor on the Western Front

Tanks as an integrated part of Allied operations

Part VI: 1918 - The Last Offensives

Maturity. Tanks in the last offensives. Allied and German models

Part VII: Winter Wars - Russia & Poland

The tanks in practical use and tank doctrines during the Russian revolution and the Polish campaign

Part I: Introduction

The tank concept can actually be traced well back to the Renaissance. The first to put it on the paper and effectively built a model (possibly to a 1:2 scale), for proper military purposes was the Florentine genius, Leonardo Da Vinci. His "tank" mainly originated from a series of protected ram experiments and a proposals to Leonardo's protector, the powerful Condottiere Ludovico il Moro (then Duke of Milan). It was not intended to attack fortifications but to break the "pike and shot" formation, a solid, mobile and massive human "fortress" formed up of a large number of pikemen surrounded by smaller detachments of arquebusiers.

This formation had dominated the battlefield for almost three centuries and was very effective as the arquebusiers delivered continuous fire while being protected by a massive wall of pikes against cavalry and infantry alike. The wooden structure of Leonardo's tank was sloped and thick enough to absorb bullets and deflect cannonballs, while at the same time delivering a punishing fire all around from its many light culverins.

The main problem was actually the way such a wooden monster could be moved. Only human or animal force were available back then, and even if Leonardo shows in his drawings cranks and shafts for two men, these would have been far from sufficient for pulling the sheer weight of this mobile fortress and fire at the same time. Modern calculations and reconstitutions, based on Leonardo's unique manuscript, showed it should have weighed nearly 2 tons.

Another strange feature, but faithful to Leonardo drawings, was a purely mechanical propulsion. While mastering clockwork devices, Leonardo had produced some "robots", including a walking lion which was displayed at Francis' I court. However the "tank" wouldn't have been equipped with such a device, as it would have had to cope with difficult terrains and a very short autonomy. Ludovico il Moro, although impressed, never ordered such a contraption built.

Part II: The Deadly Equation

Nobody was prepared for the bloody stalemate which prevailed during the First World War. Officers from all countries had in mind brash pictures or daring offensives with wavering flags and trumpets, epic cavalry charges and massive infantry squares marching under fire, bright uniforms, tactical genius and glory. A quite romantic view which was familiar to the commoners, the very same which then embarked with happiness and chants onto the trains. But quickly the grim reality which took place was that of an attrition war, with death on an industrial scale. The early French offensives sank before the whirling staccato of the German Mauser machine-guns. After a full retreat, the German offensive was miraculously stopped on the Marne, a few dozen miles north-east of Paris. From Belgium to Switzerland, all the opponents entrenched themselves. Artillery, barb wire and machine guns took their toll on every offensive. On the German side, some attempts to break the stalemate included assault squads equipped with portable machine guns, grenades, but also gas and flamethrowers. To blow up the trenches, artillery was insufficient, so another vicious weapon was used: the mine (in fact already in use since late medieval times).

Despair started sinking in after it was seen that all major offensives, like those of Nivelle in 1916, the Von Moltke offensive at Verdun or the dreadful Somme offensive by Sir Douglas Haig, were literally drawn in blood. To deal with this deadly equation, various experiments were made, some of them quite odd-looking or simply pathetic. The personal iron armor, the portable iron shield, a wooden structure covered with iron and then machines, the electric tank, the "mobile fortresses", the "automatic wheels" and pedrails to blow up the barb wire. None showed any promise.

The idea of the "tank" in the modern meaning of the word, appeared simultaneously in France and in Great Britain. In the latter, it was due to Lt. Col. Ernest Swinton, and in the former due to Col. Jean Baptiste Estienne. Both advocated the use of the Holt Tractor, which was then largely in use with the Allies as a gun tractor. This led to further developments and, despite many setbacks, culminated in 1916 when the first operational tanks were put to the test.

Part III: The Holt Tractors

The invention of the Caterpillar track and its practical application by Benjamin Holt gave birth to a new land transportation system with great torque and pulling power, up to its agricultural tasks and with good military potential. Internationally known and widely used by agriculturally reformed large farms, but also moving and transporting logs in the New World, the Holt tractor was already a mechanical legend. The flagship model, the 120 Holt, was marketed since 1914. It was purchased in large numbers, first by Great Britain and France to be used as an artillery tractor. Nearly 10,000 were used. So, it was natural to choose a large tractor to pull the weight of an armored box, its equipment and fuel. It took little time to discover the best suitable model for the worst terrains.

The Holt 120 (for 120 hp), which was much more capable than the model 70, was chosen to tow a weight of 10 tons. The problem encountered by the engineers who tried to adapt the tractor to his new task, was the quick apparition of issues with the resistance of the track shoes. This was particularly clear on the testing of the Lincoln machines ("Little and Big Willie"). The former was created especially for the test of extra-large pads, able to bear the brunt required, but also a suitable suspension system. Tests were thus conducted on both sides of the Channel, the British with their prototype "Big Willie" creating the basis of their first operational tank, the MK.I. The French, under the leadership of Colonel Estienne, devised the Schneider CA quickly, but production was not without difficulty.

So in 1916, Great Britain was the first to deploy its Mk.I tanks, during the Somme offensive, especially at Flers-Courcelette, Sept. 16, 1916, were 49 tanks were deployed. Let's look more specifically at this model: the Holt chassis had, after many changes and specifications, been completely reworked. Being initially too short, it was considered unsuitable for crossing trenches. It had nevertheless preserved the Caterpillar suspension, and many other details of the "Big Willie", which would give the true prototype of the Mk.I, the "Mother". Weighing nearly 30 tons, with a Foster-Daimler engine delivering about 105 hp, the Mk.I could move only with agonising slowness. The weight was the result of a complete redesign of the concept for the best possible crossing capabilities. In this case, the huge tracks, going all the way around the machine, enclosed a narrow central hull hosting the eight-man crew.

Part IV: 1916 - First Blood

These two models, the Mark I and Schneider CA-1, were the first tanks in operational history. It took almost a year and a half of painful technical development and testing, strong will from a few promoters, administrative battles and support from the highest level for this idea to be born. The concept were developed in parallel in the United Kingdom and in France. The latter had taken a slight advantage at first, but the former managed to produce and deploy their tanks faster. These famous diamond-shaped models remain by far the best known visual icons of the conflict.

Starting with the "Mother", the series prototype, the British built close to 2,000 units in five versions until 1919, by sticking to their proven formula and constantly improving it. The French however, made the choice of having multiple separate designs. The first, given by Joffre to Schneider, the second, designed by the army, for the army, by Saint Chamond and the third designed from private funds, the Renault FT. Finally, the design choice of the latter would set a new standard and impose a great leap forward.

So in 1916, Great Britain was the first to deploy its Mark I tanks during the Somme offensive, especially at Flers-Courcelette, Sept. 16, 1916, were 49 tanks were deployed. Let's look more specifically at this model: the Holt chassis had, after many changes and specifications, been completely reworked. Being too short initially, it was considered unsuitable for crossing trenches. It had nevertheless preserved the Caterpillar suspension, and many other details of the "Big Willie", which would give the true prototype of the Mk.I, the "Mother". Weighing nearly 30 tons, with a Foster-Daimler engine delivering about 105 hp, the Mk.I could move only with agonising slowness. The weight was the result of a complete redesign of the concept for the best possible crossing capabilities. In this case, the huge tracks, going all the way around the machine, enclosed a narrow central hull hosting the eight-man crew.

The main armament was not located in a turret (this was tested, but rejected for reasons of stability), but in a "barbette", hosting a naval gun, the famous "6 pounder" (57 mm) that was common on the deck of any ship, from destroyers to the largest battleship. The concept had been well proven and the weapon was available in large quantities. The "barbette" was the preferred system, placed into the center of the lozenge. W G Wilson, whom led the project, as specified by the army, split the Mk.I into two different series. 250 Mark I's were "males", armed with two 6-pdr pieces, and the others "females" only equipped with machine guns. The latter, exchanged their expensive water-cooled Vickers, with more recent models, the Lewis and the Hotchkiss air-cooled machine guns. Besides the four servants for the guns, the other four crewmen were dedicated to manoeuvring, operating the gearbox, brakes, differentials and two tracks. A complex system, which posed coordination difficulties, mostly because of the unbearable environment, scorching heat, deafening noise, petrol fumes, oil and toxic exhaust gases (there was no wall separating the engine from the crew). To this was added the internal finish of the armor plates, made up of boiler steel. Where there was an impact, even if the projectile did not penetrate, an internal metal explosion was triggered, filling the crowded interior with shrapnel. In fact, crews quickly adopted a complete protective outfit (thick leather belt, leather helmet with chain-mail, etc).

The French, meanwhile, devised a tank that looked more like the experimental Little Willie. Ultimately, the Schneider CA was basically an armored box with a frontal gun and machine-gun ports and ballmounts, mounted on a modified 75 Holt chassis. the original idea of col. Estienne envisioned it as an armored transport vehicle, embarking troops (in an "armored carriage"), crossing no-man's land safely, and deploying them right at the entrances of the enemy trenches. However, after tests, the engine was found incapable of supporting the weight of the main armored body. The idea was deemed impractical and abandoned, returning to a pure tank, for clearing machine gun nests, fortified positions, preceding and supporting the infantry assault. The length of the tractor train, although already increased, was found not to be sufficient for crossing wide trenches, but a tail "sabot" contributed to some improvement. In addition, the vehicle was high, with relatively low ground clearance. The 55 hp Schneider engine was barely able to propel the fourteen tons it had to carry. Only 150 had been built by mid-1917, as the project suffered delays, when the production lines stopped and shifted to a supply model. With the opening of the training school at Beaulieu, the high attrition rate due to unscrupulous maintenance in adverse conditions was significantly reduced, but an inadequate armor and poor placement of fuel tanks contributed to its precipitous withdrawal.

Part V: 1917 - Full Armor on the Western Front

The engagements of 1917 will bring their load of utter disillusions and hopes about tanks. Since the first offensives actions on the Somme, the German Army learnt how to deal the best way with this new threat and gained the upper hand while using at best their artillery, or improvising at infantry-level. It was indeed showed that despite its apparent inefficiency against the tanks armor, machine-guns could cause internally the poor quality plates to literally disintegrate into nasty shrapnells for the crew, injuring and disabling the open transmission, engine, or other mechanical parts. Throwing a grenade over the less protected roof was found also quite efficient. But the most efficient way to destroy these slumbering targets was light, agile field artillery. Germans gunners quickly learnt to destroy tanks still out of reach by direct fire, and artillery observers how to anticipate the relative movements of tanks during an artillery barrage.

The first French tank battle took place on april, 16, 1917, the Nivelle Offensive. It involved most of the Schneiders available (132), engaged at once at Berry-au-Bac. This was a complete disaster as the German Gunners had already received instructions on how to deal with tanks and where ready for them. For the few that reached a practical firing range (most had been lost due to poor maintenance, breakdowns, or just were bog down en route), the German gunners targeted an obvious weak point, the badly-placed front fuel tank. One by one, all survivors of the muddy lunar landscape were blasted by exploding high-octane fuel before even getting into position to cause some damage? Because of this, they were called later "mobile crematoriums". This was just a footnote on the immense and futile man slaughter which was part of these serie of massed frontal assault, achieving however until may some objectives with the capture of 187 guns, taking 28500 prisoners, and inflicting around 160 000 German casualties for some 200 000 French casualties. Despite their poor results, Schneiders and St Chamonds (92 in all) were once more engaged at the Battle of La Malmaison in october. But the results were similar, and due to the soaked terrain, the attrition rate was even greater. Few tanks reached the German lines. After this, the French Army led by General Ptain as he himself put it preferred "waiting for the tanks (the numerous and promising Renault FTs) an the Americans".

On the British side, in june and july in Flanders, around 200 tanks were engaged, with mixed results. By november, the British Army led another major offensive with 187 tanks, at the battle of Cambrai. It was the first time the new Mark IV was deployed in such numbers. This tank was much improved in every directions, including an armor able to sustain the German armour-piercing bullets. In total 476 tanks would be deployed in these offensives for 178 losses, some of which were recovered later by the Germans after their successful counter-offensive, using Sturmtruppen. By december, 3, Sir Douglas Haig ordered a general retreat from the Hindenburg line. The territorial gains were real, but the tanks did not much to this combat that largely involved a better coordination between infantry and artillery to succeed. British Colonel J.F.C. Fuller, chief of staff of the Tank Corps had his arm succeed on the battlefield despite a horrendous attrition rate, and tanks indeed helped to secure a breakthrough, although later wasted by the complete absence of coordination with infantry. Some were also engaged in urban combat, to their dismay.

First experiences during the early months of 1917 had shown how much the Allied tanks were prone to breakdowns, that they were severely underpowered and vulnerable against gunfire. But they also proved, first thanks to the element of surprise, and thereafter because the Germans were unable to formulate a response, that their concept was sound and they could possibly make the long awaited breakthroughs. During the last months of 1917 new models were being developed. The British had improved the Mk.I/II and were able to deliver a brand new mass-production model, the Mk.IV. It would be the spearhead of all offensives in the British sector. At the same time, the man behind the Mark I, William Tritton, devised a new kind of machine, the light tank. With the standard Mark I's clearly being too slow to operate in the way they were originally meant to, he designed a cavalry tank, which was fast enough to exploit breakthroughs. This was the Mark A "Whippet". But late 1917 and mid-1918 offensives showed the effectiveness of combined-arms tactics that employed infantry support and (real) cavalry alongside tanks.

Part VI: 1918 - The Last Offensives.

As the lessons of tanks use were properly digested and integrated, two new models were introduced: On the British side, the Mark V with Wilson's epicyclic gearing which greatly simplified the steering (one driver was now sufficient), and lately lengthened versions, the "stars" to cross the large German anti-tank trenches. On the French side, this was the nimble Renault-FT. This revolutionary design, and ford-inspired industrial mass-production helped to secure the right numbers of tanks for the right time. Although the FT was not able to sustain gunfire, and was too small to cross effectively large trenches, the combination of gun-armed and MG-armed vehicles and new tactics of close support with infantry helped to achieve far better results than before. The little Renault was there to "overwhelm" the enemy.

The Battle of Villers-Bretonneux was just one of these events, which occured on april, 24, 1918. It saw the first tank-to-tank engagement of the whole war, and first in history. Although the Germans were confident in their antitank tactics and their own assault squads, the kaiser authorized developments which led to the A7V, as well as other German types which were never ready on time. The Sturmpanzerwagen A7V was a colossus of a tank, of the "box-type". Based on a short holt chassis, this lumbering beast was even slower than an infantryman walking at normal pace, but impressive, with one gun and bristling with machine-guns. This day, a single one was spotted by a Mark IV platoon. The platoon comprised one "male" gun version and two "female", MG-armed only. After two near-misses and one hit, both "Female" disengaged, and the "male" resumed the gunfight. After very close near-misses, the A7V disengaged, thus ending this rare encounter in a draw.

With the combination of new tanks in mass, fresh American troops, the allies seemed to take advantage in the last months of the war, just after the German great summer offensive which saw few tanks engaged. The German high command showed how small, well-trained and well-equipped elite infantry squads could secure a quick breakthrough and deep penetration in enemy territory, without using any tank. However after this advance without clear objectives, and over-extended lines, the allies took the offensive again, and their counter-attack led to the quasi-destruction of these experienced forces. Despite great success had been achieved and the combination between infantry, artillery, planes, and tanks reached its zenith in the end of 1918, the Germans still inflicted punishing losses to the French and British tank units. At the battle of Amiens in august for example, no less than 72% of the Allied Tank Corps was destroyed in the first four days in the offensive. By the 64th day of the battle, 41% of British tanks engaged had been destroyed in action. On November 5, only 8 were left for the whole the British tank corps. Most were attributed to artillery in direct fire, new grenades, new AP ammunitions, and mortars. Technology of the time just prevented the use of thicker armor due to the lack of power. Apparently no engineer thought to use light and compact but very efficient aviation engines instead of buses, trucks or car engines.

In France grand plans for the last armored offensive in massive scale were put on paper by col. Fuller and by Col. Estienne, the latter speaking of "swarms of light tanks" to overwhelm the enemy. The Renault FT of which over 14,000 units had been envisioned to be produced in France, USA and Italy was to be at the forefront of these offensives. Two new tanks were in active development by 1918: the gargantuan FCM-1 and a rhomboid tank with tracks running along its full length, in the British fashion, the Saint Chamond 2. At the same time, the British had been proficient: they built the first self-propelled artillery, the Gun Carrier Mark I (carrying the BL 60-pounder field gun), lengthened variants of the Mark V, the "stars" designed to pass the very large trenches of the Hindendburg line, and William Tritton and Major Wilson worked on rival projects, the Mark B and the Mark C, both replacements for the "Whippet". At the same time, a joint-venture between the UK and the USA, for a new heavy model to be built en masse, mostly in the United States, had successfully passed all tests and was ready for pre-production: the Mark VIII "Liberty tank".

But the German revolution came as a real surprise. Berlin was in full revolt, the Kaiser was deposed, and the soldiers on the front felt betrayed, leaving no choice but an humiliating Armistice. Subsequently, nearly all previous tank mass-production series were cancelled. Some models were produced through the early twenties, in order not to loose the gain of costly researches. The Mark B "Whippet" and Mark C "Hornet" had 152 units delivered by 1922 and 151 units of the Mark VIII "Liberty" by 1923. In France, 10 FMC-1 had been finally delivered at astronomical costs by 1923. No modern tank had been planned in France before 1930, and only cosmetic changes to the basic FT took place (like the Renault NC 1/2/3).

Part VII: Winter Wars - Russia & Poland

The Versailles treaty, signed on June 28, 1919, had redefined the map of Europe. Three so-called "buffer states" were drawn on the Baltic coast: Lithuania, Latvia and Estonia. Poland was restored to its former historic borders, occupying most of Prussia and large extents of the western Russian territories and was given the Danzig Corridor to ensure its access to the the Baltic Sea. Since the Revolution of 1917, the Russian Soviet Federative Socialist Republic was in a state of latent civil war. No Bolshevik committee was invited to the Paris Peace Conference. Even more so the Allies were inclined to military support the exiled, loyalist "White" Russian faction. Before the new territorial gains of Poland, an improvised force of the Ukrainian People's Army clashed with the newly born Republic of Zakopane, which will become later part of the Second Polish Republic (Rzeczpospolita Polska). This was the beginning of a full-scale war, with two major battles, at Lviv and Przemysl, both in 1918. Border conflicts also occurred during this period with the Czech, culminating in a full scale war with Czechoslovakia in January 1919. Soon Poland was declare an independent and sovereign state. The Bolsheviks felt this as a direct threat from their old natural enemy, and the Red Army rushed to the borders. This was the beginning of the Polish-Soviet war of 1919 which spanned two years and ended with the treaty of Riga in 1921.

During this event, the Polish state received military advisers and councilors (mostly former French and British officers, including the young De Gaulle), and of course weapons, rifles, ammunition, most notably Schneider 75 mm guns, but also some French FT tanks.

Leonardo tank Leonardo Da Vinci was apparently the first to design a wooden tank, which lacked only a suitable propulsion form to turn into reality. Although impressed with it, Ludovico Sforza, the Duke of Milan, never ordered any to be built. The tank had to wait for four more centuries before appearing on the battlefield.

However the very idea of an armored mobile device could be traced back into the Bronze Age, with the first battering rams, later with the sophisticated siege assault towers of the Assyrians and 400 years after with the huge Helepolis of Demetrius Poliorcetes (known as "The Besieger"). Read more about ancient hellenistic siege towers.

Ideas and concepts
By the beginning of the war, there were already concepts of tanks in the air. Just like the beginning of automobile industry, many technologies were explored with the same confidence and ingenuity. Therefore Steam-powered, electric, even remote-controlled tanks were tried, as well as the way to make contact with the ground, opened to all fantasies. The pedrail concept for example, was the great alternative to the tracks, proceeding from the same idea, but with bigger elements. To crush barb wire, many concepts were tried, including the "skeleton tank", with very large overall tracks and the crew compartment inside, of which several variants were tested, to the monster of them all, the Russian "Tsar tank" and its gigantic metallic wheels.

French Levavasseur project (1903). With a crew of three, a 80 hp engine, full caterpillars, this canon autopropulseur would have crossed the battlefield with ease, but it was eventually buried by the Artillery Technical Committee in 1908. In Great Britain, Lincolnshire, the firm Hornsby built the first functional caterpillars, later to attract great interest from the admiralty for possible armed developments.

H.G. Wells "land ironclads" novel first published in Strand Magazine in 1903 had a tremendous impact of the head of the British "land battleship" committee in 1915, Sir Winston Churchill. These armoured monsters were steam-driven and rolled on eight pairs of giant pedrail wheels.

This wartime project "Flying Elephant" was closer from the concept of land battleship than ever. After conceiving the Mark I in 1915, William Tritton envisioned a new kind of shell-proof tank. Such requirements called for a massive, heavy hull with 51 mm armour plates, and associated powerplants which in turn, needed room. As a result, the Tank Supply Committee approved a single prototype in june, plans being ready by august 1916. Although the overall dimensions were not so impressive (8.36 m long), with 200 tons, and another pair of belly inner-tracks for better traction. The plans were later modified and the armour halved to regain some agility while the main concept derived as a tank hunter. 20 were initially planned for production when the whole project was halted. Here is the 1/35th scale model reconstitution at Bovington.

The Stothert & Pitt prototype pedrail landship chassis on trials in 1915-16 by the Trench warfare Dept. It was 32 tons heavy "unladen" but could still run at 15 mph thanks to two 100 hp engines. This vehicle came from Murray Sueter and B.J. Diplock idea in 1914 of a 25-ton armoured tractor. By 1915, RE Compton designed an armoured and tracked APC for 50 me, and later Churchill himself, enamoured with HG Wells idea, ordered no less than 12 Landhsips of the Diplock and Wheeled type. B.Joseph Diplock nevertheless developed from the pedrail wheel and later pedrail track, the caterpillar track in 1910, of low friction and low ground pressure. The HG Wells idea stuck to the RNAS and later the Army staff minds much for the duration of the war. Since the Mark I, all British tanks were massive and slow, with naval-inspired barbettes. Until 1918 and the arrival of the Whippet, the light tank idea, suited to replace the traditional cavalry was not in the minds of the Generals, but of engineers, like William Tritton. Despite many Pedrail-type tanks were tried, including on French and German sides, none make it to production.

The Boirault Machine. An experimental French "pedrail" rotating frame formed of six large 4x3m metallic frames linked together, with a central powerplant inside. The idea was to literally crush barb wire, but proved on trials underpowered, fragile, and nearly impossible to steer.

The French Frot-Laffly landship. It was basically an armoured compactor with several machine-gun portholes. On 18 March 1915 it was tried ans successfully crushed as intended lengths of barb wire, but mobility was reduced.

The Fortin ("Fort") Audiot-Gabet, looked modern with its electrical propulsion and revolving turret, 37 mm cannon-armed, but trials showed it was impractical since it was fed by a wire cable to conduct electricity. A single shot on this cable and it was stopped. Moreover, the available length of the cable barely allowed for the short distance of the enemy trenches.

In the same idea of a compactor, with heavy rollers to crush barb wire, the Breton-Prtot machine was tried in january 1915. It had an animated saw to cut through wires, and large rollers to crush what left and enlarged the gap for infantry to follow. It was armored but the crew was left largely unprotected, and had a Hotchkiss 37 mm naval gun installed at the rear, but the lack of mobility of the original Bajac agricultural tractor doomed any production. Jeffery tractors were also considered, but by mid-1915 it was too late as the tanks were much advanced and promising.

The Holt tractor. Instrumental as an artillery tractor to carry pieces of ordinance too heavy for horse-drawn carriages on the worst terrain, was based on the caterpillar track patent. Since these machines were already well known, well-used and already purchased in large quantities, with many already available spare parts, it was not long before engineers and officers tried to have "armoured boxes" hastily mounted on top. But this burden proved soon too much for the extremely muddy and cratered landscape. Nevertheless, "fortune tanks" has been made since during the thirties, forties, and occasionally during civil wars until recently.

The famous Souain experiment, led in december 1915 was considered to be the first serious army trials of a armoured Baby Holt to be derived as a tank platform. Provision for the Breton wire cutters were installed to a provisional wooden hull. General Philippe Ptain was present to these successful trials which did much to promote the ideas of Col. Estienne.

The British Tritton Trench-Crosser, tried in may 1915. This British machine was equipped with two 8-feet large tractor wheels, and carried girders on an endless chain which were lowered and provide a solid grip for the wheels to cross trenches. Cumbersome and complicated, it was abandoned.

By july 1915, a double, articulated chassis based on the US Bullock Creeping Grip caterpillar tracks was tried. This was a relatively sound idea since this prototype was deemed more agile, but the trials failed nevertheless. Holt Gas-Electric tank
Holt Gas-Electric tank (1917): When the United States entered the first world war, they were already acquired to the concept of tanks following the British initial successes, but lacked any to equip their newly formed units, despite the obvious industrial capacity for producing one. Among the numerous projects flourishing in 1917 was Holt's proposal for an artillery-carrying tank, based on the Holt Model 75, with pivoting track frames. This box-like model was 7 feet 9.5 inches (2.375 m) tall, 16 feet 6 inches (5.03 m) long, and 9 feet 1 inch (2.77 m) wide, weighted 25 tons for a 90 hp gasoline engine coupled to electric motors which activated the drive sprockets. It was armed with a 75 mm Vickers mountain howitzer and two Browning M1917 in sponsons. Quite heavy and slow its performances were disappointing on rough terrain and slopes, and the prototype rejected by the US Army.

The Killen-Strait tractor was a strange mix tested on 30 june 1915 with a tricycle configuration of two rear tracks and a single front one which provided steering, and an armoured Delaunay-Belleville automobile chassis. Field tests showed the concept to be a dead end as far as trench crossing was concerned.

William Tritton's Lincoln number one machine, with Bullock tracks and creeping grip tractor suspension. As a secret project, it is covered by a tarpaulin when not in use. This experiment prompted the Little Willie construction, then the larger "big willie", which ultimately led to the "Mother", the ancestor of the entire British rhomboid tank families.

Links about WW1 warfare and armored vehicles

Landships II : Formely and saved from deletion by its team, this website is perhaps the only comprehensive portal about armoured vehicles of the great war, with most (if not all) types and related resources useful for studies as well as modelling.
April tank of the month: The T34/76 April 2012
May tank of the month: The M3  Halftrack May 2012
June tank of the month: The Panzer III June 2012
July tank of the month: The Cruiser VI Crusader July 2012
August tank of the month: The Char B1 bis August 2012
September tank of the month: The T26 September 2012
April tank of the month: The M3 Lee/Grant October 2012
November tank of the month: The Panzer IV November 2012
December tank of the month: The Mathilda infantry tank December 2012
January tank of the month: The Type 97 Chi Ha January 2013
February tank of the month: The Russian KV-1 February 2013
March tank of the month: The M4 Sherman March 2013
April 2013 tank of the month: The Merkava MBT April 2013
Sd.Kfz.250  Hanomag May 2013
June tank of the month: The Panzer III June 2013
July tank of the month: The T34/85 July 2013
August tank of the month: M4 Sherman Part 2 August 2013
September tank of the month: The Panther September 2013
October tank of the month: The Renault FT October 2013
November tank of the month: The Churchill November 2013
December tank of the month: The IS-2 December 2013
Chitsmas tank of the month: The Tiger January 2014
February tank of the month: The February 2014
March tank of the month: The AMX-13 March 2014
December tank of the month: The Centurion April 2014
May tank of the month: The T54/55 May 2014
June tank of the month: The Leopard I June 2014
July tank of the month: The M48 Patton July 2014
August tank of the month: The T-72 August 2014
September tank of the month: The AMX-30 September 2014
October tank of the month: The Chieftain MBT October 2014
November tank of the month: The M60 Patton November 2014
December tank of the month: The T-64 December 2014
January tank of the month: The M1 Abrams January 2015
February tank of the month: The STUG-III February 2015
March tank of the month: The AMX-56 Leclerc March 2015