“Nellie” (aka the “White Rabbit”) was a machine doomed from the start as it was designed to solve an obsolete problem. Nellie was an armored vehicle made to cut a trench through defensive works so that other machines could advance through the trench and bypass the defensive line.
As a pet project of Winston Churchill, work continued on the White Rabbit long after it became clear that it was not the only solution to the problems that tanks faced due to defensive structures.
As time went on, it became clear that Nellie wasn’t even a particularly good solution to these problems. It had a turning circle of 1.6 kilometers (1 mi) and was almost unable to be steered. Conditions inside the cramped cockpit were unbearable. Perhaps worst of all, serious questions were raised about the advisability of using a near-stationary machine with a long guiding trench behind it in the era of bombing runs.[
Despite Churchill’s enduring belief in the project, it was finally formally shelved in 1943. Churchill acknowledged that the project would have been mothballed years earlier if not for his promotion. In the end, he declared that he was “responsible but impenitent” for his misguided enthusiasm.