The First World War was an unprecedented catastrophe that shaped our modern world. Erik Sass is covering the events of the war exactly 100 years after they happened. This is the 170th installment in the series.

February 24, 1915: Churchill Convenes Tank Committee

The backbone of modern conventional armies, tanks may seem like an obvious idea—and indeed the model of a self-contained, mobile fortress to dominate the battlefield has been around for thousands of years. The Roman “testudo” or tortoise formation allowed legionaries to advance through hails of arrows, and during the Renaissance Leonardo da Vinci sketched a design for an armored vehicle (below), “safe and unassailable, which will enter the closed ranks of the enemy with their artillery… And behind these our infantry will be able to follow quite unharmed and without any opposition.”

In 1903 the British futurist H.G. Wells imagined armored vehicles breaking through entrenched defenders in his short story “The Land Ironclads,” inspired by the heavy casualties inflicted by massed rifle fire in the Boer War. Propelled by mechanical “feet” on wheels and followed by columns of regular infantry, Wells’ land ironclad “continued to move regardless of the hail that splashed its skin with bright new specks of lead,” eventually “hoisting itself farther and farther over the trench,” while “methodically shooting down and breaking up any persistent knots of resistance.”

However armored battlefield vehicles would remain in the realm of science fiction until the invention of the internal combustion engine in the second half of the 19th century. A huge improvement over steam engines, in internal combustion engines exploding gasoline or diesel vapor replaced steam in pistons, allowing designers to do away with cumbersome boilers as well as the huge quantities of coal needed to power them. The new, more compact engines enabled a flurry of engineering feats including the first automobile, invented by Karl Benz 1885, the first practical submarine, designed by John Holland in 1898, and the first airplane, invented by the Wright brothers and first flown in 1903.

While submarines held intriguing strategic potential and airplanes captured the popular imagination, automobiles had far and away the largest economic impact in the near term, with Henry Ford’s creation of the Model T in 1908 promising to transform middle class lifestyles and fueling another wave of industrialization in the U.S. Before long it would also change the face of war.

Following the outbreak of the Great War and the emergence of trench warfare in 1914, attention quickly turned to development of armored vehicles using internal combustion engines to break through enemy defenses. As early as December 1914 French military engineers were working on the Frot-Laffly landship, named after its designers, which combined armor plates with cannons and machine guns, but used wheels instead of tractor treads, resulting in limited mobility across open terrain. Around the same time Thomas Hetherington, a commander in the Royal Naval Air Service, saw a heavy vehicle using “Diplock pedrails,” a type of tread, and recommended it to First Lord of the Admiralty Winston Churchill. The idea was also advocated by Colonel Ernest Swinton, an influential military officer and writer who apparently suggested the codename “tank” to conceal the true purpose of the device (the term is sometimes also credited to Churchill).

Brushing aside the fact that the armored vehicles clearly fell under the category of land warfare, on February 24, 1915 Churchill convened the first “Landships Committee” (cleverly using a bit of naval imagery to bridge the gap). The committee began by considering two main prototypes for armored vehicles—the first, a bizarre “Bigwheel” model without treads, the second a large truck-like vehicle designed by Colonel Rookes Crompton, incorporating the Diplock Pedrail caterpillar tread then in use in agricultural tractors, intended to carry up to 50 infantry soldiers into battle.

On March 28 Churchill ordered twelve of the Pedrail models and six of the Bigwheels, but both soon proved impractical because of mobility issues. In April Crompton revised the Pedrail design to produce an articulated vehicle to address its mobility shortcomings, which the committee approved in May, but the articulated version turned out to have even more issues.

With Churchill’s encouragement the committee pressed on, and Crompton now turned to a new kind of caterpillar tread used on tractors made by a U.S. manufacturer based in Chicago, the Bullock Tractor Company. In August 1915 he obtained a specially manufactured extra-long version of the “Bullock Creeping Grip,” as the tread was known. However by this time the committee had lost patience with Crompton’s fixation on the articulated vehicle design, which they regarded as a clear failure. Crompton was removed from the project, but his idea of using the Bullock Creeping Grip proved to be a crucial contribution.

Meanwhile beginning in July 1915 William Tritton, managing director at the Foster’s Works factory in Lincoln, collaborated with Lieutenant Walter Wilson of the Royal Navy Reserve, who had worked as an automobile engineer before the war, on a new design: much smaller than either of the first two prototypes, the “Lincoln No. 1 Machine” (below) combined the Bullock Creeping Grip with a squat, compact (and non-articulated) body.

Although the tracks failed at the first test in September 1915, the “Lincoln No. 1 Machine,” nicknamed “Little Willie,” had confirmed the soundness of the basic concept; by now the idea had also received the endorsement of British Expeditionary Force commander Sir John French (Churchill was forced to step down following the disaster at Gallipoli in April-May 1915; in June his successor, Arthur Balfour, confirmed that work on the project would continue).

Tritton and Wilson returned to the drawing board to design a new vehicle with an unusual “rhomboidal” shape to make it easier to climb in and out of trenches. Known by a number of nicknames, including “The Wilson,” “The Centipede,” “Big Willie,” and eventually “Mother,” the new vehicle (top) was designed to meet War Office specifications that it be able to cross an eight-foot-wide trench and climb parapets up to four feet six inches tall. It would be ready for testing by November 30.

See the previous installment or all entries.