Cultivator No. 6 was a behemoth, ahead of its time machine that emerged amidst the escalating Second World War. A brainchild of Winston Churchill, the trench digging machine was designed to break the stalemate of trench warfare that traumatized the Brits during the First World War. Not wanting a repeat of millions of casualties, Churchill sorted through previous ideas about advancing trench digging using mechanical means.

But while the First Lord of the Admiralty has a notable reputation as an outstanding problem solver and visionary, he wouldn’t predict the dramatic shift of the course of WWII. And despite recognizing that the project would be ineffective, Churchill persisted in pressing on and squandering valuable resources when Britain desperately needed them.

Churchill’s Brainchild

The year was 1939, and Germany had just invaded Poland. Prime Minister Arthur Neville Chamberlain appointed Churchill as First Lord of the Admiralty to the Cabinet. With his previous experience, the latter wasted no time devising a plan to give them an advantage in trench digging. His original concept was to have an armored trench digging machine that could burrow under the ground and dig straight through No Man’s Land, where troops and vehicles would then access the enemy line. But this wasn’t an easy feat as technology was still far from where it is today.

Nevertheless, Churchill launched the project using his prerogative and assigned the development to renowned ship engineer J.H. Hopkins under the top-secret Department of Naval Land Equipment (NLE). After numerous different designs were submitted, the engineers finally received Churchill’s approval. It was a machine resembling the rhomboid shape of the earliest Great War tanks and was slated to mass produce 240 units.

cultivator no 6 British Trench-digging machine
(Image source: Wikimedia Commons)

Codename the Cultivator No. 6, engineers figured that for this to actually work, they would need a power of at least 1,000 horsepower, which would be shared between moving and digging. Initially, they thought of tapping for Rolls-Royces for their latest (at that time) Merlin engine. But the Royal Air Force reserved first and was given absolute priority.

Enter Sir Harry Ricardo, a notable engineer who was among the first to develop the internal combustion engine. He suggested using two 600hp Paxman diesel engines instead, which was good because it ended up a better match. With this, the digging and automotive systems can be powered separately rather than sharing one powerplant.

Nellie, The Trench Digger

Keeping the project under wraps, the trench digging machine had several names to disguise its true purpose, including NLE Tractor, Cultivator No. 6, White Rabbit No. 6, and Nellie. Churchill also referred to it at times as his mole.

Probably paying homage to Mark I (aka Little Willie), the trench digging prototype was unofficially called Nellie (or it could be wordplay for the NLE department). Nellie had two main parts: the head, responsible for the actual digging, and the body, which provided the machine’s overall movement.