The First World War was remembered by the participants for the colossal number of trenches, wire and other obstacles, as well as other attributes of trench warfare. The difficulty of equipment and overcoming positions and their means of protection led to the emergence of several new classes of equipment. In particular, already during the war, the first projects of earth-moving equipment began to appear, which made it possible to simplify the preparation of trenches. Before the outbreak of World War II, these ideas were further developed. One of the results of the new work was the appearance of the NLE Trenching Machine Mark I or White Rabbit combat trencher.
By 1939, the situation in Europe deteriorated and indicated the imminent start of a major war, which forced states to pay special attention to the technology and weapons of troops. At the same time, the British command had the idea of creating a special earth-moving machine capable of overcoming enemy obstacles. A promising model was supposed to create a passage for its troops, along which soldiers and equipment could get as close as possible to the enemy's positions, bypassing various obstacles. It is interesting that the author of the original idea was the British Prime Minister Winston Churchill, who since the time of the previous major war had his own accounts with trenches and barriers.
Combat trencher on trial. In the foreground is Winston Churchill. Photo Aviarmor.net
The basic idea was simple enough. It was necessary to create a special machine with earth-moving equipment. Immediately before the attack, such a technique, under cover of night or a smoke screen, was supposed to break through a new trench of great length and width, passing under the enemy's obstacles and reaching the first line of his trenches. An offensive along a freshly dug trench, as the author of the idea believed, made it possible to quickly prepare the battlefield for an attack, and in addition, reduce the likelihood of hitting the attacking soldiers and equipment. The main "target" of the new machines was to be the so-called. The Siegfried Line is a complex of fortifications in the western part of Germany.
The Prime Minister's proposal did not interest the military department. The numerous shortcomings of the combat trencher became a cause for doubt. Such a technique was not distinguished by high mobility, because of which it could become a convenient target for enemy artillery. Also, the project was seen as too complicated both in terms of development and in terms of serial construction and further operation of equipment. Nevertheless, the high position allowed the author of the idea to initiate full-fledged design work. Soon, the developer of the future engineering vehicle was selected, and some plans for mass production were also identified.
The development of the project was entrusted to specialists from a specially created Department of Naval Land Equipmen (NLE). It is by the name of this organization, as well as taking into account the purpose of the technology, the new project received the designation NLE Trenching Machine Mark I - "NLE development trencher, the first model." Subsequently, the abbreviated unofficial name Nellie appeared. In addition, the unusual project had other names. So, at the production stage, the nickname White Rabbit ("White Rabbit" - in honor of the character in the book by Lewis Carroll, who was heading to the hole) appeared. The "agricultural" name Cultivator # 6 was also used, which made it possible to hide the true purpose of the machine.
The front of the machine, the plow and the chain excavator are clearly visible. Photo Imperial War Museum / Iwm.org.uk
The specialists of the newly created Department had no experience in the development of engineering equipment, which is why the main design work on the new machine was transferred to Ruston-Bucyrus Ltd. This company was engaged in the production of excavators and other earthmoving equipment. As a result, she had the experience needed to build a combat trencher. It should be noted that the authors of the NLE Trenching Machine Mark I project took on the new order with enthusiasm, so the development did not take much time. By the end of 1939, specialists had prepared part of the documentation, and also made a large-scale demonstration model.
In December, a model of the trencher, which had a length of about 1.2 m, was presented to the Prime Minister. In addition, W. Churchill showed it to some representatives of the military department, including the future chief of the General Staff, Edmond Ironside. Sir Ironside became interested in the project and became its supporter, which greatly contributed to the continuation of the work. It is interesting that the first mention of the name "Cultivator No. 6" dates back to this time. The rapid implementation of design work led to the fact that on December 6, 1939, Prime Minister W. Churchill announced the possibility of an early start of mass production at a high rate. By the spring of 1941, the army could receive up to two hundred "White Rabbits".
On January 22, 1940, the development company received a contract for the future serial construction of engineering equipment of a new type. In early February, an additional document appeared, specifying the amount of equipment required. The first contract was to build 200 NLE Trenching Machine Mark I machines in the Infantry modification ("infantry") and 40 "tank" Officer. Different modifications of the trencher had minimal differences associated with ensuring the combat work of different types of troops. Simultaneously with the preparation of serial production, W. Churchill made an attempt to interest the French army in the new development. The possibility of the outbreak of war should have contributed to the emergence of interest in earth-moving equipment.
Driver's cabin located on the rear section. Photo Drive2.ru
By the end of 1939, the development company had identified the main design features of the machine. The specific purpose and unusual requirements have led to the formation of a non-standard and original look. So, the car should have been divided into two main units responsible for moving and cutting trenches. In addition, the project suggested some other unusual ideas.
In the finished form, the White Rabbit combat trencher consisted of two main sections. The front was equipped with all the necessary equipment for interacting with the ground, and the rear was responsible for moving the machine. Due to the peculiarities of the technique and specific balancing, the authors of the project had to use a relatively long and heavy rear section, which was responsible for movement. The front, in turn, was smaller and lighter, but carried all the target equipment. The sections had connecting mechanisms with the ability to change their relative position. By lowering the front section, the crew could increase the depth of the trench, while raising it - decrease it.
The front section of the NLE Trenching Machine Mark I was an earth-moving machine itself. She received a complex-shaped body with an open lower frontal part and attachments for equipment. The frontal part of the body was made in the form of a structure of several sheets located at different angles to each other. There was a wide oblique leaf and a narrow upper vertical one. Provided for the use of vertical sides and a horizontal roof. In the upper part of the sides, next to the stern, there were two protruding frames of the belt conveyors.
A plow was located on the frontal part of the body to create a trench. It had a wedge-shaped plan with a relatively narrow lower and widened upper parts. This design provided the creation of a trench, the lower section of which was wider than the body of the engineering vehicle. The upper "wings" of the dump made it possible to divert the soil up and to the sides, excluding the possibility of its falling back into the trench. The plow was rigidly fixed to the front of the body using a set of beams. At the same time, the lower cut of the plow was at a certain height above the supporting surface.
Left side of the rear section. The side hatches are open, the technicians are servicing the units. Photo Imperial War Museum / Iwm.org.uk
The proposed plow design did not provide soil picking up to the depth of the bottom and tracks of the machine. Because of this, the front section received additional means for digging in the form of a chain excavator. Behind the plow, in the lower part of the forehead of the body, there was a large window in which there were two chains with a large number of small buckets. The bucket teeth were directed upwards and the chain was fed from below. During operation, buckets on belts had to take soil from the space behind the plow and feed it to the aft part of the section. There it was poured into a container, from which it was brought out with the help of onboard conveyor belts. Conveyors located at an angle ensured the unloading of soil outside the trench, forming low parapets.
The aft part of the front section of the "White Rabbit" had attachments for connecting to the rest of the units. In addition, this unit received a shaft for transmitting torque from the power plant to the earthmoving equipment. Inside the front section, there was only special equipment. Crew jobs were not provided there.
The rear section of the trencher was a long, close-to-rectangular unit. A characteristic feature of the section hull was the use of tracks covering the side compartments. In the front of the section hull, there were transmission devices that transmit power to the earthmoving equipment. There was also a small control compartment for the crew. For the convenience of observing the terrain, the control compartment had a turret with a double hatch in the roof. Access to workplaces was provided by side doors. A compartment for two engines was located behind the turret. The feed was given under the transmission connecting the engine with the drive wheels of the caterpillar propeller.
Aft part of the trencher. Photo Imperial War Museum / Iwm.org.uk
Due to its large size and weight, the rear section of the car was divided into two parts. The compartments in a divided form could be transported with the existing means of transporting heavy armored vehicles. The division took place according to the volume between the two engines. Also, during transportation, a third platform was required to transport the front section of the machine.
Initially, it was planned to equip a promising engineering vehicle with Rolls-Royce Merlin aircraft engines with a capacity of 1000 hp. However, during the development of the project, it turned out that such motors under continuous load are capable of maintaining a power of no more than 800 hp, and in addition, the pace of mass production left much to be desired. Serial engines were enough only for installation on aircraft, but not on new ground equipment. The engine problem was solved with 600 hp Paxman-Ricardo diesels. They showed the required characteristics, and also were not used in other projects.
The combat trencher was supposed to receive two engines at once. One of them ensured the movement of the machine, the second was responsible for the operation of earth-moving devices. The "running" engine with the help of a mechanical transmission transmitted power to the driving wheels of the aft position. Large hatches in the sides of the hull were used to service the engines. The hatch covers, which were large enough, folded down, becoming a platform for placing a technician.
The principle of the machine. Figure Henk.fox3000.com
The car received a fairly simple chassis based on a caterpillar propeller. To guide the tracks along the perimeter of the side surface of the hull, a stern drive wheel and a front guide were used. Supporting rollers were placed above them, almost at the level of the roof. The upper branch of the caterpillar, in turn, was supported by special rails. A large number of road wheels of small diameter were installed in the lower part of the hull without suspension and with minimal gaps. For the correct distribution of the large weight of the machine, the chassis received 42 road wheels on each side. Large-link tracks with a width of 610 mm with developed lugs of an angle structure were used.
In the event of a collision with wire or other obstacles in front of enemy positions, the engineering vehicle received some additional funds. On the roof of both sections, from the plow to the stern bevel, a large number of racks with wire attachments were provided. The stretched wire was supposed to divert the barriers from the turret and the roof with the units installed on it.
The project involved the construction of equipment in the Infantry and Officer modifications. The "infantry" vehicle did not have any additional funds. The second modification, in turn, had to carry a special ramp. It was assumed that light tanks and other equipment with appropriate characteristics would be able to rise from the trench to the surface along this unit. There were no other differences between the two modifications.
The trencher is being tested. Photo Aviarmor.net
The total length of the NLE Trenching Machine Mark I trencher in the working position exceeded 23.6 m. The maximum width of the structure excluding the plow was 2.2 m, the height was up to 3.2 m. The front section with a plow and an excavator accounted for 9.3 m of length … The section width reached 2, 2 m, height - 2, 6 m. The front unit of the disassembled rear section had a length of 7, 1 m, a width of 1, 9 m and a height of 3, 2 m. The high height was associated with the use of the crew turret. The aft compartment differed in length of 8, 64 m and a height of 2, 6 m. The equipped weight of the vehicle was determined at 130 tons. Of these, 30 tons were in the front section. The rest of the weight was distributed as follows: 45 tons for the front unit of the rear section and 55 tons for the stern.
During operation, the combat trencher had to dig into the ground to a depth of 1.5 m. Half of this depth was worked by a plow, the other by a chain excavator. The width of the trench was determined by the width of the lower unit and was 2.3 m. The shape of the plow and the operation of the excavator with additional conveyors provided the formation of two parapets, increasing the total height of the trench. The power of the propeller engine, according to calculations, made it possible to develop a speed from 0.4 to 0.67 miles per hour during combat work - 650-1080 m / h. At the maximum speed per hour of operation, the earthmoving equipment could “process” more than 3700 cubic meters of soil with a total weight of up to 8 thousand tons.
From the assembly site to the future trench on the battlefield, the White Rabbit machine had to move under its own power. At the same time, it was possible to develop a speed of up to 4, 9 km / h. The fuel reserve was sufficient to enter the battlefield and a fragment of a trench up to several kilometers long.
At the beginning of 1940, the development company received an order for the production of first a prototype vehicle, and then serial equipment. Due to the complexity and labor intensity, the construction was seriously delayed. While it lasted, the British military tried to formulate principles for the combat use of trenchers. Later, certain methods had to be adjusted taking into account the experience of battles in France. An analysis of the methods of breaking through the defense used by Germany showed the inexpediency of using combat trenchers. Nevertheless, W. Churchill insisted on preserving such equipment, but he had already expressed a proposal to reduce the order for production vehicles several times.
Prototype and command representatives. Photo Imperial War Museum / Iwm.org.uk
Soon, the military was finally disillusioned with the original car, which from the very beginning raised serious doubts. Nevertheless, the construction of the prototype was nearing completion, which is why it was decided to complete the assembly and test it. In June 1941, the first and only completed prototype of the NLE Trenching Machine Mark I entered trials. By this time, no one considered "Nelly" as a real technology of the engineering troops, but the project was still interesting from the point of view of general possibilities. During the tests, it was planned to test the real capabilities of the original combat vehicle.
According to some reports, by the middle of 1941 there were more than three dozen engineering vehicles at various stages of construction. In addition, it is mentioned that, in addition to the first prototype, several other machines were completed, which also became prototypes for testing. According to such reports, a total of up to five prototypes were involved in the checks.
The tests of the new earth-moving machine lasted for about a year. The prototype confirmed compliance with the calculated characteristics and could solve the assigned tasks. However, it was found that there were no prospects in terms of real combat use. The unusual concept had a number of characteristic drawbacks that did not allow achieving noticeable results.
The only advantage of the "Cultivator No. 6" project was the possibility of creating a trench for safer movement of soldiers to the enemy lines of defense. Along with this, the car had a number of serious problems. So, it turned out to be too difficult to manufacture and operate. During earthworks, the trencher could not maneuver, which to some extent made it difficult to create a trench for the infantry. Also, low mobility made the vehicle an easy target for artillery. The use of armor of acceptable thickness did not allow solving this problem and providing the required survivability.
Modern model of a combat trencher. Photo Henk.fox3000.com
Also, by the time the tests began, it became clear that obstacles and fortifications could not be particularly difficult for modern military equipment when used correctly. The troops of Nazi Germany overcame the French defenses without significant problems, the objects of which could not hold back the offensive. Subsequently, the available techniques allowed the German troops to begin a successful advance deep into the territory of the Soviet Union. The Germans did not use combat trenchers, however, even without them, they showed high efficiency of offensives.
In terms of technical, operational and tactical features, the NLE Trenching Machine Mark I combat trencher could not give the troops any significant advantages. Serial production of equipment was canceled. The built prototype (or prototypes) after testing was not needed by the army. The prototype went into storage without any hope of returning to testing, not to mention the continuation of production and the beginning of operation in the army. No one needed the NLE Trenching Machine Mark I / Nellie / White Rabbit / Cultivator # 6 battle trencher was kept at one of the British military bases until the early fifties. Then it was decided that he wasted his place and should go to the scrap. Soon a unique piece of equipment was sent for disassembly and melting.
Original and bold ideas sometimes lead to real revolutions in their field. Nevertheless, much more often such proposals do not give the expected results and remain in history as technical curiosities. W. Churchill's proposal to overcome obstacles and fortifications of the enemy also did not become the beginning of the next technical revolution. From the very beginning, the military was skeptical about the original idea, and later their opinion was confirmed in practice. A special combat trencher turned out to be too difficult for the army, and subsequent events showed that such a technique was simply not needed. The "White Rabbit" had no future and could not dig a single "hole" on the battlefield.
