The “Little Willie”
The Mk.I tank was the first operational tank in the British army and in the world. It was based on the “Little Willie” (The Lincoln machine) project, supported by the Landships Committee, headed by Walter Wilson and William Tritton. It was largely an attempt to overcome the previous model’s issues. One of the solutions was to avoid adding a turret and mounted the guns in sponsons instead. The Little Willie, also known as the “Lincoln machine number one”, was tested and modified, and the lessons were taken in account for the development of the Mark I and its prototype, called “Big Willie” or, more commonly, “Mother”.
“Mother”, the production prototype
In December 1915, the final prototype was ready for the first trials, which took place in April 1916. It was named officially “His Majesty’s Land Ship Centipede”, but was know colloquially as “Mother” or “Big Willie”, as a joke directed towards the German Kaiser and the crown prince, both named Wilhelm. In the meantime, the “Tank Supply Committee” succeeded the Landship Committee, under the chairmanship of Albert Stern. Other members included Ernest Swinton, the head of the committee, General Haig, who acted as a liaison officer, Hugh Elles who would later become the commander of the tank force in France. The trials were held up in an impressive reconstruction of no-man’s land with trenches, parapets, craters and barbed wire, and impressed all officers except the Secretary of War, Lord Kitchener. Despite of this, an order was secured for 150 tanks in two batches, with one order being issued on 12 February 1916 and another on April 23.
The Mk.I was elaborated to encompass all the lessons learnt from the Little Willie trials in 1915. No turret (giving a low center of gravity), armament mounted in sponsons, bolted hull made of boiler panels, newly designed tracks inherited from the Little Willie and a large, easily recognizable rhomboid hull, with the tracks surrounding the hull, making up the entire length of the machine. This shape could not be underestimated. While Great Britain learned the difficult trade of crossing heavily cratered, muddy terrain with the previous Lincoln machine, a radical solution was adopted, which proved adequate to the task, but too radical at the same time, and would emerge in postwar years.
Indeed, a running track of this size allowed to gap the largest known trenches of the time, negotiate craters, while the front three meter recess allowed the vehicle to climb almost any obstacle. But, in addition of being heavy, these full-running tracks caused a safety problem for the crew members, who could get caught in it and be dragged under the tank. It also limited the ability to store anything on top, save for a narrow portion of the central hull. Visibility was perfectible and a lot of space was lost by cramming all the return rollers. A nightmare for an engineer, as well as the maintenance crew.
Propulsion relied on a six cylinder petrol engine at the rear of the hull, with no compartmentalization, due to the transmission system tunnel, which ran through the tank and, more importantly, because, at that stage, the engine was relatively untested and finicky enough to force engineers to need to be able to get their hands on the engine just in case. In addition, the engine had to push quite hard to carry the 28 tons of steel with its just 105 horsepower, with a crushingly low of 3.7 hp per tonne. Not surprisingly, the burden was made greater by the incredibly sticky nature of the mud, which was shown by recent studies to just stick to metal, which meant a tremendous force was required to extract whatever was plunged in to.
At least in the case of the tracks, the flat shape and serial arrangement made it more likely to “surf” on the surface, although taking along a large amount of mud in the process. Being clogged in a sinkhole was just the level of effort which the valiant little Daimler was not ready to undertake. Breakdowns were commonplace and ruined the early stage of the assault, largely diminishing the number of tanks that just had the luck to make their way into the no-man’s land and reach the destination. Also, the engine not being separated from the fighting compartment proved ruinous for the crew, which fell ill quite quickly, but that feature remained unchanged until 1918. The general staff didn’t see this sickness as a limitation either, given the relatively short distance which had to be crossed between opposing trenches. A mobility aspect which was incorporated into the design concerned the removable sponsons, allowing the tank to be narrower and thus, providing easier transport by rail.
The crew comprised eight men, of which two were drivers (one for the gearbox and the other for the brakes) and two others controlling the gears of each track. This system needed perfect coordination, which was difficult due to the noise inside and the protective leather helmets they used. The four others were gunners, serving the six-pounders and the machine guns, depending on the armament. 50% of the Mk. Is were armed with two guns in the sponsons and three machine-guns (two in the sponsons, one axial in the hull), named “males”, and the other half were “females”, armed with five machine-guns. These were either Vickers models or the 8 mm (0.31 in) Hotchkiss air-cooled equivalents. The tanks were quite big, weighing 28 tons with an eight meters long hull and an overall length of nearly ten meters with the additional tail wheel, another feature kept from the Little Willie. It was designed to help crossing very large trenches, but later proved impractical and was dropped.
No less than 150 Mk.Is were built at William Foster & Co. of the Lincoln Metropolitan Carriage and Metropolitan Carriage, Wagon & Finance Co. at Wednesbury. The first order of 100 was increased to 150 in April 1916, acting as a pre-series for further mass-productions. The Foster deliveries concerned 37 males, while Metropolitan Carriage, Wagon, and Finance Company, of Birmingham, delivered 113 Tanks, including 38 “males” and 75 “females”. Later on, two rails were mounted over the hull to handle a wooden beam, used for unditching. The first were ready in a hurry and deployed in August, just in time for the Somme Offensive. From the end of 1917 and until 1918, some of the surviving ones were converted as signal tanks with a large antenna at the base of the driver’s cab, participating in the battle of Cambrai. Others were converted as supply tanks.
Succession: the Mk. II and III
As the Mark I showed many limitations, the next batch of 50 tanks (25 females and 25 males) were built at Foster & Co and Metropolitan for training purposes only. There were some claims about their unhardened steel plates, but all data seems to show that the Mk.IIs were regular Mk. Is with a few modifications for training purposes. Some 20 were sent to France for advanced training and those left remained at the Wool training ground in Dorset.
However, in 1917, there weren’t enough tanks operational for the offensives planned in April 1917 near Arras, and twenty surviving Mk.Is and all the Mk.IIs remaining in Britain were put in action (despite some protests), suffering high casualties, mainly due to the new armor-piercing bullets the Germans employed.
The Mark IIIs were training tanks as well (the great improvements were still planned for the Mk.IV) and were all fitted with Lewis machine guns in smaller, lighter sponsons. Otherwise, few changes were visible at the beginning, as this batch of 50 vehicles was designed to incorporate all the Mk.IV improvements. Deliveries were slow and none left Great Britain.
The Mark I In Action
Their first operational use was in September at Flers-Courcelette, but this first attempt was a near disaster. Most of the tanks broke down on their way, others bogged down in the mud. However, despite the lack of training of their crews, some managed to reach their designated objective, if only too few. Only 59 were part of this attack, most of them being captured afterwards by the Germans. The first issues quickly arrived at the War Office. When they appeared however through the fog, they had an uncanny psychological effect on the German troops, which fled their trenches, leaving their machine guns. The distant roar and clinging of the tracks, and later the slow-moving masses emerging from the fog which resembled nothing built yet were enough. But their ability to take punishment and return fire was compelled by the fact the Germans were caught completely unaware of their existance. A real surprise achieved by the well-guarded secret behind the name that stuck ever since, the “tank”.
The noise, the smell and the temperature that reached nearly 50 degrees Celsius were just unbearable. There were powerful emanations of carbon monoxide, cordite, fuel and oil vapors, all made worse by poor ventilation. The crews often opened the narrow door situated just behind the sponson, in an attempt to get some fresh air in. With poor training and almost no internal communication, steering was enormously difficult, resulting in mechanical over-stress, causing many breakdowns.
Another factor was the petrol engine, overwhelmed by the weight of the hull combined with the very sticky, heavy mud typical of the region, something that was rediscovered when excavating and experimenting with the supposed battlefield of Agincourt. Coordination between the tanks also proved inadequate, theoretically by using a set of fanions, flags, lamps, semaphores and other devices inspired by navy practice. There was no radio on board. Pigeons were used instead to report positions and status with the General Headquarters.
Crew security was also an issue inside the tank. If the 8 mm (0.31 in) plates were proven bullet proof, each impact produced mini-shrapnel inside the hull, injuring anybody inside. Following the first reports, thick leather jackets and helmets, or a combination of leather and chain-mail, were provided to the crews. Spall liners would take ages to come into view.
Weight: 28 tons
Length, width and height: 9.9m, 4.2m, 2.4m
Fuel capacity: 227.3 litres
Max speed: 5.9km/h
Fuel consumption: 5.9 litres/km
Armament: Two six-pounder (57mm) quick-firing and four 7.62mm Hotchkiss air-cooled machine guns
Type: Tank; Acc/Top Speed: 1/3; Toughness: 15/14/14 (2/1/1); Crew: 8 (Commander, driver,mechanic, 2 loaders, 3 gunners)
Notes: Heavy Armor, Tracked
• Three .303 Vickers machine guns, one forward, left, and right sides (5,640 rounds total)
• Two 6-pounder cannon in side sponsons (200 rounds total)
• Five .303 Vickers machine guns, one in front and two on each side (12,780 rounds total)
There were two types of Mark I tank: 'male' and 'female'. Male tanks mounted a six-pounder gun in each sponson, plus three light machine guns. Female tanks had two heavy Vickers machine guns in place of the six-pounders.
The Hotchkiss six-pounder was an adapted naval gun with a range of 6,860 metres. It was served by a gunner and loader, neither of whom could stand or sit comfortably in the cramped interior. The gunner aimed using a simple telescopic sight, but the vibration of the tank was so severe that careful aiming was impossible unless the tank was completely stationary. Each male tank carried 334 shells, stowed in special tubes arranged around the interior of the tank.
The machine guns, also Hotchkiss, were for close defence if the tank was attacked by enemy infantry. One was located in each sponson, with a third at the front, firing through a loophole between the driver's and commander's visors. These guns tended to be temperamental due to the heat and vibration inside the tank.
The Mark I was powered by a large Daimler (of Coventry) six-cylinder engine with a 13 litre capacity, but it only produced a relatively puny 105 brake horsepower. Chosen for its smooth, quiet running, the engine was nonetheless located in the same compartment of the tank as the crew, where the heat, noise and exhaust fumes were almost unbearable.
The engine was started by four members of the crew winding a large crank handle. The engine was water-cooled, with the large radiator situated at the back of the tank. This was served by a heavy duty fan, which drew air from inside the tank and may have slightly alleviated the dreadful conditions inside.
Petrol was on a 'gravity feed' to the carburettor. This meant the two internal 25 gallon (113.5 litre) containers had to be situated high up, on either side of the front cab. If a tank became stuck in a nose-down attitude, the tank would stall, making it necessary to feed petrol to the engine manually.
A far greater danger was fire. If a tank was struck by a shell that ignited the fuel, the crew had little or no chance of escape. Additionally, the average range of a tank on its internal fuel supply was only 20-25 miles, depending on terrain, so crews carried as many extra petrol cans as possible on the roof of the tank where they were extremely vulnerable to damage. Petrol leaking into the tank from the roof could force the crew to evacuate.
Caterpillar tracks were key to the success of British tanks in World War One. When it was realised that commercially-available tracks were simply not up to the job, Albert Tritton of Foster & Co, Lincoln, came up with a new design. This enabled the adoption of the characteristic all-round track layout which gave British tanks their unrivalled cross-country performance.
Simplicity and strength were the key factors, but there were drawbacks. Small diameter rollers, located along the lower frames, were unsprung, so tanks bumped hard across rough ground, adding further to the discomfort of the crew.
A broken, or 'thrown', track could disable a tank at once, and replacing it was hard work. To prevent this, adjustable idler wheels at the front were used to keep the tracks taut, and track links were flanged so that they would not fall away from the rollers when the tank crossed a trench.
The Mark I had a crew of eight men, four of whom were required just to drive it. The process was complicated. The driver had control of a clutch, footbrake, hand throttle and primary gearbox, which gave two speeds forward and one in reverse. The commander, sitting to the driver's left, operated the brakes. At the back of the tank, two 'gearsmen' worked secondary, two-speed gearboxes located within the track frames.
For any major change in direction (known to tank men as 'swinging'), the driver stopped the tank and put the primary box in neutral. Depending on the direction of turn, the gearsmen selected a gear on one side and neutral on the other, while the commander held the brake. The driver then put the primary box in gear and the driven track 'swung' the tank around. The tank then had to stop again while the gears were reset.
The steering tail device worked on a principle similar to that of a boat's rudder and gave the tank a laborious 18 metre (diameter) turning circle. It was widely regarded by crews as a nuisance and was removed a few months after the Mark I was introduced.
In order to limit the weight of the Mark I to a 'manageable' 28 tonnes, the thickness of its armour plate was limited. In vital areas, such as the front, it was 10 mm thick. Elsewhere it was a minimal 6 mm. In theory, the crew were reasonably safe from small arms fire and shrapnel. Anything heavier would smash straight through the plate and probably wreck the tank.
The art of manufacturing thin armour was still in its infancy so the quality varied. Bullets were known to pierce the armour, particularly on the sponsons. Even if bullets failed to penetrate, the crew suffered a great deal from 'splash' - molten lead from the core of spent bullets that found its way through gaps in the armour to burn exposed skin and damage eyes.
The sponsons on 'male' tanks were naval in origin and were adopted in place of a rotating turret. A turret would have raised the centre of gravity to an unacceptable height, and being directly above the engine might well have roasted the crew.
The sponsons also had their flaws: they added weight, made it difficult for the driver to judge the width; would often become wedged in soft ground; and had to be removed and refitted when the tank was transported by train.
The male sponson included a pedestal for the gun and a curved shield of armour plate that rotated with the gun as the gunner swung it round, ensuring that the aperture was adequately covered at all times. The doors of the tank were located to the rear of each sponson.
In addition to the fumes, the cramped conditions and the deafening noise, it was virtually pitch black inside the Mark I when going into action. Every door, flap and hatch was shut tight against bullets, shrapnel and bullet 'splash' yet the crew had to be able to see outside both to drive and fight.
At the front, the commander and his driver had large flaps that could be opened in layered stages as required, and slim periscopes which poked up through holes in the cab roof. Elsewhere in the tank were narrow vision slits with crude periscopes which used shatterproof strips of shiny steel rather than glass blocks.
German troops soon learned to fire at the tank's vision devices, which the crews tried to camouflage with paint. Other apertures, covered by teardrop-shaped flaps, were designed not for vision but to allow crew members to use their revolvers.
If conditions inside the Mark I were appalling - deafening noise, roasting heat, suffocating fumes from the engine and the choking smell of cordite when in action - the men learned to live with it and still function as a team. Given that they were often in extreme danger and working in near-total darkness, their commitment was remarkable. Although the tanks were originally regarded as expendable, their crews took much pride in them, christening each one with an individual name, and repairing and recovering them after an action where possible. The Mark I crew comprised eight men.
Commander (front left)
In 1916, he would have been a young officer. Besides the usual duties of command - determining the route, watching out for targets and the care of the crew - he was responsible for working a pair of steering brakes in conjunction with the driver. If the ground was bad or the route uncertain, the commander would often get out of the tank and walk ahead, testing the ground with a stick - holding a lit cigarette behind his back if it was dark - at the risk of enemy fire and being run down by his own tank.
The Driver (front right)
The driver was regarded as the most skilled and valuable member of the crew. He was responsible for navigating the tank, gear changing, operating the throttle, applying the foot brake and operating the steering tail device by means of a steering wheel. He also supervised maintenance of the engine, clutch, gears and tracks.
Secondary Gearsmen (at the rear of the tank)
The gearsmen were stationed on each side of the tank. They operated the secondary gearboxes relating to the individual tracks. They also passed forward ammunition, greased the tracks and operated the light machine guns.
Gunners and Loaders
In a 'male' tank, each six-pounder gun was served by a gunner and a loader. The gun was moved by the sheer physical exertion of the gunner, using a shaft under his right armpit to elevate and swing the weapon. He aimed using a telescopic sight and operated the firing mechanism manually.
The first tank crews came from virtually every regiment in the British Army. Consequently, there was little conformity in cap badges or uniform early on, but eventually they were made a branch of the Machine Gun Corps. This became the Tank Corps in July 1917, the Royal Tank Corps in October 1923 and the Royal Tank Regiment in April 1939.