Military thinking during the inter-war years led to an assumption that any future conflict would again involve extensive trench warfare. With this in mind and along with the
memory of the appalling loss of life in the trenches during World War One, Churchill wanted to find a way of allowing troops and supplies to advance in relative safety and
quickly break through the German front line. He came up with the idea of machines which would dig large trenches through No Man's Land under cover of darkness and the
noise of an artillery barrage. Troops and tanks would follow in these trenches, coming to the surface at or behind the enemy front line.
The mechanical digging machines designated NLE (Lit; Naval Land Equipment) aka Nellie, No man's Land Excavator, White Rabbit No 6 or Cultivator were then produced in
working model form and successfully demonstrated the feasibility of the concept. On 7th February 1940 Cabinet and Treasury approval was given for the construction of 200
narrow 'infantry' machines and 40 wide 'officer' machines. The original planned production rate was 20 machines (requiring 40 engines) per week.
It her final form Nellie was 77' long, 6' 6" wide, 8' high and made in two sections. The main section, driven on caterpillar tracks, looked like a greatly elongated tank and
weighed 100 tons. The front section, weighing another 30 tons, was capable of digging a trench 5' deep and 7' 6" wide. It comprised a plough which cut the top 2' 6" of the
trench, and 'pick and shovel' cutting cylinders which excavated the bottom 2' 6". The spoil was carried away by conveyors to the top of each side of the trench to create 3'
parapets. Nellie could move at just over half a mile an hour, removing some 8,000 tons of spoil in the process. When she reached the enemy's front line she would stop and act
as a ramp for following tracked vehicles to climb up out of the trench onto open ground. Originally she was to be powered by a single 1,000bhp marine version of the
Rolls-Royce Merlin engine but it was soon pointed out this engine could only produce 800bhp under continuous load, less than was required for the task. Shortly after, all
Merlin engines were earmarked for the RAF and Sir Harry Ricardo recommended using two Paxman-Ricardo engines of the type already in service with the Navy and of a
proven design. The decision was made to use two 600bhp Paxman 12TPs which necessitated a complete redesign of Nellie. One engine was used to drive the cutter and
conveyors at the front and the other used to propel the machine itself.
Then the war very quickly took a totally unexpected course. After Dunkirk and the fall of France the Nellie project collapsed. Large scale production of NLE's was
abandoned and the engine capacity was turned over to the Admiralty. Field trials of the pilot machine commenced in June 1941 and were not completed until about January
1942. Production in the end comprised, apart from the pilot machine, four 'infantry' and one 'officer' machines. The last surviving 'Infantry' example was scrapped in the 1950s.
Nellie - The History of Churchill's Lincoln-Built Trenching Machine John T Turner, The Society for Lincolnshire History & Archaeology, ISBN No 0 904680 68 1
