Temistocle
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Hi, I searched the entire forum, but I did not find a thread about the Cultivator Number 6, a projected trenching machine; maybe it is well known to some of the readers, but I think it need a thread due to its particularity. Here the Cultivator as described by Winston Churchill in his book "Gathering the storm", Volume 1 of his World War II history:
Appendix J, Book II
CULTIVATOR NUMBER 6
During these months of suspense and paralysis [end 1939, beginning 1940, ndr] I gave much thought and compelled much effort to the development of an idea which I thought might be helpful to the great battle when it began. For secrecy’s sake this was called “White Rabbit Number 6,” later changed to “Cultivator Number 6.” It was a method of imparting to our armies a means of advance up to and through the hostile lines without undue or prohibitive casualties. I believed that a machine could be made which would cut a groove in the earth sufficiently deep and broad through which assaulting infantry and presently assaulting tanks could advance in comparative safety across No-Man’s-Land and wire entanglements, and come to grips with the enemy in his defences on equal terms and in superior strength. It was necessary that the machine cutting this trench should advance at sufficient speed to cross the distance between the two front lines during the hours of darkness. I hoped for a speed of three or four m.p.h.; but even half-a-mile would be enough. If this method could be applied upon a front of perhaps twenty or twenty-five miles, for which two or three hundred trench-cutters might suffice, dawn would find an overwhelming force of determined infantry established on and in the German defences, with hundreds of lines-of communication trenches stretching back behind them, along which reinforcements and supplies could flow. Thus we should establish ourselves in the enemy’s front line by surprise and with little loss. This process could be repeated indefinitely.
When I had had the first tank made twenty-five years before, I turned to Tennyson d’Eyncourt, Director of Naval Construction, to solve the problem. Accordingly I broached the subject in November to Sir Stanley Goodall, who now held this most important office, and one of his ablest assistants, Mr. Hopkins, was put in charge with a grant of one hundred thousand pounds for experiments. The design and manufacture of a working model was completed in six weeks by Messrs. Ruston-Bucyrus of Lincoln. This suggestive little machine, about three feet long, performed excellently in the Admiralty basement on a floor of sand.
Having obtained the active support of the Chief of the Imperial General Staff, General Ironside, and other British military experts, I invited the Prime Minister and several of his colleagues to a demonstration. Later I took it over to France and exhibited it both to General Gamelin and later on to General Georges, who expressed approving interest.
On December 6, I was assured that immediate orders and absolute priority would produce two hundred of these machines by March, 1941. At the same time it was suggested that a bigger machine might dig a trench wide enough for tanks. On February 7, 1940, Cabinet and Treasury approval were given for the construction of two hundred narrow “infantry” and forty wide “officer” machines. The design was so novel that trial units of the main components had first to be built. In April, a hitch occurred. We had hitherto relied on a single Merlin-Marine type of engine, but now the Air Ministry wanted all these, and another heavier and larger engine had to be accepted instead. The machine in its final form weighed over a hundred tons, was seventy-seven feet long, and eight feet high. This mammoth mole could cut in loam a trench five feet deep and seven-and-a-half feet wide at half-a-mile an hour, involving the movement of eight thousand tons of soil. In March, 1940, the whole process of manufacture was transferred to a special department of the Ministry of Supply. The utmost secrecy was maintained by the three hundred and fifty firms involved in making the separate parts, or in assembling them at elected centres.
Geological analysis was made of the soil of Northern France and Belgium, and several suitable areas were found where the machine could be used as part of a great offensive battle plan. But all this labour, requiring at every stage so many people to be convinced or persuaded, led to nothing. A very different form of warfare was soon to descend upon us like an avalanche, sweeping all before it. As will presently be seen, I lost no time in casting aside these elaborate plans and releasing the resources they involved. A few specimens alone were finished and preserved for some special tactical problem or for cutting emergency anti-tank obstacles. By May, 1943, we had only the pilot model, four narrow and five wide machines, made or making. After seeing the full-sized pilot model perform with astonishing efficiency, I minuted “cancel and wind up the four of the five ‘officer’ type, but keep the four ‘infantry’-type in good order. Their turn may come.” These survivors were kept in store until the summer of 1945, when the Siegfried Line being pierced by other methods, all except one was dismantled.
Such was the tale of “Cultivator Number 6.” I am responsible but impenitent.
There is a breif account about the travel for the demonstration in France in the book "Winston Churchill's Toy Shop" by Stuart Macrae.
More info about the Cultivator in the following links, with pictures and drawings:
Cultivator (Wikipedia)
ThinkDefense
Appendix J, Book II
CULTIVATOR NUMBER 6
During these months of suspense and paralysis [end 1939, beginning 1940, ndr] I gave much thought and compelled much effort to the development of an idea which I thought might be helpful to the great battle when it began. For secrecy’s sake this was called “White Rabbit Number 6,” later changed to “Cultivator Number 6.” It was a method of imparting to our armies a means of advance up to and through the hostile lines without undue or prohibitive casualties. I believed that a machine could be made which would cut a groove in the earth sufficiently deep and broad through which assaulting infantry and presently assaulting tanks could advance in comparative safety across No-Man’s-Land and wire entanglements, and come to grips with the enemy in his defences on equal terms and in superior strength. It was necessary that the machine cutting this trench should advance at sufficient speed to cross the distance between the two front lines during the hours of darkness. I hoped for a speed of three or four m.p.h.; but even half-a-mile would be enough. If this method could be applied upon a front of perhaps twenty or twenty-five miles, for which two or three hundred trench-cutters might suffice, dawn would find an overwhelming force of determined infantry established on and in the German defences, with hundreds of lines-of communication trenches stretching back behind them, along which reinforcements and supplies could flow. Thus we should establish ourselves in the enemy’s front line by surprise and with little loss. This process could be repeated indefinitely.
When I had had the first tank made twenty-five years before, I turned to Tennyson d’Eyncourt, Director of Naval Construction, to solve the problem. Accordingly I broached the subject in November to Sir Stanley Goodall, who now held this most important office, and one of his ablest assistants, Mr. Hopkins, was put in charge with a grant of one hundred thousand pounds for experiments. The design and manufacture of a working model was completed in six weeks by Messrs. Ruston-Bucyrus of Lincoln. This suggestive little machine, about three feet long, performed excellently in the Admiralty basement on a floor of sand.
Having obtained the active support of the Chief of the Imperial General Staff, General Ironside, and other British military experts, I invited the Prime Minister and several of his colleagues to a demonstration. Later I took it over to France and exhibited it both to General Gamelin and later on to General Georges, who expressed approving interest.
On December 6, I was assured that immediate orders and absolute priority would produce two hundred of these machines by March, 1941. At the same time it was suggested that a bigger machine might dig a trench wide enough for tanks. On February 7, 1940, Cabinet and Treasury approval were given for the construction of two hundred narrow “infantry” and forty wide “officer” machines. The design was so novel that trial units of the main components had first to be built. In April, a hitch occurred. We had hitherto relied on a single Merlin-Marine type of engine, but now the Air Ministry wanted all these, and another heavier and larger engine had to be accepted instead. The machine in its final form weighed over a hundred tons, was seventy-seven feet long, and eight feet high. This mammoth mole could cut in loam a trench five feet deep and seven-and-a-half feet wide at half-a-mile an hour, involving the movement of eight thousand tons of soil. In March, 1940, the whole process of manufacture was transferred to a special department of the Ministry of Supply. The utmost secrecy was maintained by the three hundred and fifty firms involved in making the separate parts, or in assembling them at elected centres.
Geological analysis was made of the soil of Northern France and Belgium, and several suitable areas were found where the machine could be used as part of a great offensive battle plan. But all this labour, requiring at every stage so many people to be convinced or persuaded, led to nothing. A very different form of warfare was soon to descend upon us like an avalanche, sweeping all before it. As will presently be seen, I lost no time in casting aside these elaborate plans and releasing the resources they involved. A few specimens alone were finished and preserved for some special tactical problem or for cutting emergency anti-tank obstacles. By May, 1943, we had only the pilot model, four narrow and five wide machines, made or making. After seeing the full-sized pilot model perform with astonishing efficiency, I minuted “cancel and wind up the four of the five ‘officer’ type, but keep the four ‘infantry’-type in good order. Their turn may come.” These survivors were kept in store until the summer of 1945, when the Siegfried Line being pierced by other methods, all except one was dismantled.
Such was the tale of “Cultivator Number 6.” I am responsible but impenitent.
There is a breif account about the travel for the demonstration in France in the book "Winston Churchill's Toy Shop" by Stuart Macrae.
More info about the Cultivator in the following links, with pictures and drawings:
Cultivator (Wikipedia)
ThinkDefense
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