by Rob Arndt  

WW1 Austro-Hungarian trench digger

Inspired by the WW1 Austro-Hungarian trench diggers, Ritter Engineering sketched a colossal armored project that had it been constructed would have been the largest and longest armored vehicle in history - the mighty Midgard-Schlange.


The name Midgard-Schlange is derived from Norse/Germanic mythology: the Midgard Snake was a demonic monster which looped the whole earth with its giant length. Thor, the God of the thunder, was its sworn enemy and he often tried to kill it. Thor finally succeeded in killing the snake in the God Dawn with his hammer. Ritter, fond of the Norse/German mythology promoted by the Nazi regime named his project after the mythological snake and began preparations for designing the armored beast.


The first plans of this project were made in the summer of 1934. It was decided that the beast was to be a hybrid armored vehicle, which like a tank could drive; in addition, it would be able to tunnel like a mole underground and under water to a theoretical depth of 100 meters!! The vehicle would be made from 77 individual cells, whereby each cell would be 6.8 meters wide, 3.5 meters high and 6 meters long. These joined to form a queue of sections with an overall length of 524 meters!


At the front end a drilling head was to be mounted which would consist of 4 smaller drills of 1.5 meters diameter. The drill would be driven by 9 engines providing 8,800 hp total. Three side drills were also envisioned. For progressive movement, the tracks were to be propelled by 14 engines providing an incredible 19,800 hp. A speed of 30 km/h was calculated; underground, 10 km/h and under water, just 3 km/h. For the underwater travel there were an additional 12 engines providing 3,000 hp together. 960 m3 of fuel would be carried. On board there would be an electrical kitchen, a sleep area with 20 beds, 3 on-board workshops, several periscopes, 580 large pressurized air bottles and a large charge thrower. As armament 1,000 mine charges of 250 kg explosive would be carried, another 100 smaller charges of 10 kg explosive as secondary armament, and 2 twin machine guns. The whole vehicle would have had a loaded weight of 60,000 tons  and a crew of 30 men!

Ritter planned for the Midgard Snake to tunnel under the fortifications of the Maginot Line and into hostile ports laying down 20 explosive charges.

All this sounds quite irrational, if not impossible, for the time period; so consequently, that is one of the many reasons why it was never built. The principal reason lies, however, in the vast unsolvable technical problems with a vehicle of such immense size and proportions.

The Germans in the 1940's had more important projects to consider like developing an efficient engine with more than 1,000 hp for the "Maus" tank. Regardless, on February 28, 1935 the Midgard-Schlange plans were returned to Ritter Engineering, rejected as impractical.


The plans were not simply rejected as absurd, insane, or impossible- the request had been turned down due to lack of financial and material resources, and available manpower! Had Hitler personally ordered the machine built, work would have started immediately and by 1939 it is possible that the monster would have breathed life!


But it was not to be. Meanwhile, across the Channel…




The British, by comparison, built several high ton NLE (Naval Land Equipment) machines called “Nellie” to dig through trenches in case of German invasion. Winston Churchill came up with the idea and gave orders for an initial batch of 200 of them to be constructed in early 1940!

The construction of the French Maginot and German Siegfried Lines during the inter-war years led to a false assumption that any future conflict would again involve trench warfare. Reminded of the appalling loss of life in the trenches of 1914-18, Churchill wanted to find a way of allowing British 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 German front line. The mechanical 'mole' designated NLE, standing for Naval Land Equipment, came to be known as 'Nellie' or in Paxman's Drawing Office as 'No man's Land Excavator' - a fitting description. It was also known as the Cultivator 6  or White Rabbit 6 to disguise its real military purpose.

Man with blacked-out face with NLE is Winston Churchill himself!

The original planned production rate was 20 machines (requiring 40 engines) per week. In 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 .50 mph, removing some 8,000 tons of spoil in the process. When she reached the German’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.


The Paxman 12TP Engine

With the outbreak of war the British Government needed large numbers of powerful, yet compact, prime movers. Petrol engines were available which could have met the power to weight requirement. However in some of the envisaged applications the engines would be installed in confined spaces where the fire risk associated with petrol was a major disadvantage. There was very little choice of suitable compression ignition engines which, because of their much lesser fire risk, were the preferred alternative. One engine, however, did meet the requirement. The Paxman 12 cylinder VEE RB was already well developed and of proven performance.


A further Government requirement was that the engine should be suitable for manufacture on a large scale. Edward Paxman and his team of designers, led by Albert Howe, modified their existing engine for the purpose and so the 600 bhp 12 TP was born. Instead of having the crankcase and cylinders in one large and relatively complex casting, this was split into three pieces (hence the name 'TP' according to one source) comprising the crankcase and two separate banks of cylinders. Many more firms would be capable of making these smaller and simpler units on a sub-contract basis. Indeed an important element of the design philosophy was that all the engine's components should be capable of being manufactured in small workshops up and down the land. This would make it easier to find the necessary manufacturing capacity as well as reduce the risks of major disruption if a factory was bombed.


Paxman's Hythe Hill factory was already working at full capacity. An order for engines for 'U' Class submarines had been followed by another engine order for 'S' Class submarines. This was on top of existing production of engines for destroyers, cruisers, corvettes and frigates, generating sets for the army, tank sprockets, mines and paravanes. The Ministry of Supply, which controlled all diesel production in the country, therefore leased the Britannia Works in 1941 to provide Paxman with space to build its TP engines. The Company was appointed to manage it and at once started reconstruction work, laying down storage space, test beds, cooling water mains, and generally strengthening the original wood structure.


The Ministry of Supply enlisted over 400 engineering concerns, large and small, to produce the 1,300 or so different components required for the engine. Multiple sets of jigs and tools for the manufacture of each component were designed and made by Paxman at Colchester for issue to the sub-contractors' workshops. The parts they produced, a total of 5,000 for each 12 TP, flowed into the Britannia Works where the engines were assembled. The 12 TP was designed to be simple to produce, a necessity with wartime labour shortages. Eighty five percent of the staff taken on to build the engines were unskilled and mostly women. They also tested each engine prior to despatch.


Originally she was to be powered by a single 1,000 hp marine version of the Rolls-Royce Merlin engine. Apart from the fire risks inherent in a petrol engine, it was soon pointed out this engine could only be expected to produce 800 hp under continuous load, less than was required for the task. Shortly after, all Merlin engines were urgently needed by the RAF and Sir Harry Ricardo's advice was sought on a suitable alternative. He recommended using two Paxman-Ricardo engines of the type already in service with the Royal Navy and of a proven design. The decision was made to use two 600 hp Paxman 12TPs, necessitating a complete redesign of Nellie. One engine was to drive the cutter and conveyors at the front and the other used to propel the machine itself.


But after Dunkirk and the fall of France, the Nellie project collapsed. Large scale production of TPs for Nellie 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.) The entire project was cancelled in 1943.


Only five of the small versions of Nellie were actually completed. Four were scrapped at the end of the war and the fifth, believed to have been the pilot machine, was scrapped in the early 1950s.


For both Ritter and Churchill their great trench diggers had no impact on the war whatsoever.


Aka: Iormungandr, Midgardsormr, Midgard Serpent, and World Serpent.  


Norse. He is the son of Loki and Angur-boda.  

This serpent lives in the sea, and encircles the earth. He is so long that he has swallowed his own tail. 


This serpent was one of Loki's children, and was thrown off of the Sacred Ash, Yggdrasil, by Odin when it was just a little baby. However, this small serpent grew to encompass the world, and now the huge serpent twines around the earth, twisting and writhing. This dragon-snake had many run-ins with the mighty Thor, and the two of them will face off during the final battle on earth called Ragnarok.  Thor managed to kill the monstrous serpent with his hammer, Moljnir but its  last breath was a poisoned cloud which killed the God.





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