Landkreuzer P1000 'Ratte'
On June 23, 1942, Dir. Dip. Ing. Grote (along with Dr.Hacker) from the Ministry of Armament, who was responsible for the production of U-Boote suggested the development of a tank with a weight of 1,000 tons. Hitler himself expressed interest in this project and allowed Krupp to go ahead with it. The project was designated as the Krupp P.1000 (Ratte - Rat). This behemoth "land cruiser" would be 35 meters long, 14 meters wide and 11 meters high. P.1000 would be equipped with 3.6 meters wide tracks per side made of three 1.2 meters tracks, similar to those used in excavators working in coalmines. It was planned to power P.1000 with two MAN V12Z32/44 24 cylinder Diesel marine engines with total power of 17,000hp (2 x 8,500hp) or with eight Daimler-Benz MB501 20 cylinder Diesel marine engines with total power of 16,000hp (8 x 2,000hp). According to the calculations, this would allow the P.1000 to travel at maximum speed of 40 km/h. P.1000 would be armed with a variety of weapons such as: two 280mm gun (naval gun used on 'Scharnhorst' and 'Gneisenau' warships), single 128mm gun, eight 20mm Flak 38 anti-aircraft guns and two 15mm Mauser MG 151/15 guns.
The world will probably never see an armored land vehicle on the scale of the Ratte. Tellingly, Germans didn’t even refer to it as a tank: they called it a “land cruiser.” The Ratte was so large its dimensions had more in common with a naval vessel than a tank. It had the crew compliment of at least four heavy tanks, armament usually seen mounted on heavy cruisers like the Scharnhorst and Gneisenau, and enough anti-aircraft weaponry to ward off waves of attacking fighter-bomber. It was 35 meters long, as tall as some church steeples, and so wide that maneuvering in an urban area would have been either impossible or apocalyptic. The Ratte was so heavy it would have shattered and churned pavement like a plow through sod and collapsed all but a handful of bridges in Germany.
The Ratte’s much smaller cousin, the Maus, turned out to be a ruinous waste of resources for very limited applications in combat. Had the Ratte’s development progressed even a fraction as far as the Maus it would have devastated Germany. The Ratte was so large that it would have required naval-scale manufacturing with months of skilled laborers’ time involved in the construction of each individual tank. Just building and assembling its components would have required transportation and handling equipment usually relegated to a shipyard.
It is probably to the detriment of the world that the Ratte project was cancelled. It would have been cool just to see one of these hideous machines built and, more importantly, it would have taken the place of perhaps fifty or a hundred more useful tanks like the Panther or Panzer IV. The Ratte would have meant an earlier end to hostilities in Europe and it would have provided a damn hot ticket at a museum in the United States or the Soviet Union.
The development history of the Ratte originates with a 1941 strategic study of Soviet heavy tanks conducted by Krupp. This study also gave birth to the Ratte’s smaller and more practical relative: the Maus. From the start the Maus was envisioned as an even larger and more formidable version of a heavy tank, while the Ratte was to be a class of vehicle unto itself.
This 1941 study produced a suggestion from director of engineering Grote who worked for the U-boat arm of the Ministry of Armaments. In June of 1942, Grote proposed a 1000-ton tank that he termed a “Landkreuzer” equipped with naval armament and armored so heavily that only similar naval armaments could hope to touch it. To compensate for the immense weight of the vehicle the Ratte would have sported three 1.2 meter wide tread-assemblies on each side totaling a tread width of 7.2 meters. This helped with the stability and weight distribution of the Ratte but its sheer mass would have destroyed pavement and prevented bridge travel. Fortunately, the height of the Ratte and its nearly 2 meters of ground clearance would have allowed it to ford many rivers with ease.
Hitler became enamored with the idea of a truly super tank and ordered Krupp to set to work developing the Ratte. While development of the Ratte does not seem to have progressed very far some sources believe that a turret was completed for the Ratte and then used as a fixed gun emplacement in Norway. Several such emplacements survived the war, many mounting turrets from broken-up vessels very similar to the turret intended for the Ratte. However, despite references to a Ratte turret being used as a fixed emplacement there is no evidence that it ever existed. The Gneisenau was broken up in 1944 and its turrets were used as emplacements near Rotterdam in Holland. Similar turrets were used near Trondheim in Norway which was the supposed location of the Ratte turret.
Battery Ørland - Norway
[Originally the C turret on the Gneisenau]
Development of the Ratte was completely cancelled in 1943 by the dangerously wise German Minister of Armaments, Albert Speer. Speer exhibited an uncanny ability to cancel the more moronic and wasteful of Hitler’s pet projects and focus German resources on proven weapon systems.
Technical Mumbo Jumbo
There were two proposed power plants for the P. 1000 Ratte. One concept was powered by two MAN V12Z32/44 24-cylinder diesel engines similar to those used on German submarines. This double engine design produced a Herculean 17,000 horsepower. These were the engines used to derive the 44kp/h maximum speed of the Ratte by the Germans. The more likely engine was the Daimler-Benz MB501. This 20-cylinder marine diesel engine was identical to that used on the German fast torpedo boats or S-boots. Linking eight of these engines would have theoretically produced 16,000 horsepower. Given that the MB501 was a more proven, inexpensive, and easier to manage engine it seems likely this eight-engine design would have appeared in the Ratte prototype.
The primary armament of the Ratte was two 280mm SK C/34 naval guns mounted in a modified naval heavy cruiser turret fitting two guns instead of three. The SK C/34 was a devastating piece of artillery capable of penetrating more than 450mm of armor at its maximum effective direct-fire range of roughly five kilometers. The guns could also be elevated up to 40 degrees to achieve a range of 40 kilometers. Armor-piercing shells and two types of high explosive shells were available for these naval guns. One difficulty facing the 280mm dual battery would have been the Ratte’s inability to sufficiently depress its weapons to fire at nearby targets. Accompanying vehicles would have likely accomplished this task.
Additional armament was a 128mm anti-tank gun like that mounted on the Jagdtiger or Maus, two 15mm heavy machineguns and eight 20mm anti-aircraft guns, probably with at least four of them as a quad mount. The 128mm anti-tank gun’s location on the Ratte is a point of contention among historians. Most believe it would have been mounted within the primary turret, though some think a smaller secondary turret would have been mounted at the rear of the Ratte near the engine decking. The rear turret makes more sense logistically, but the surface area of engine decking at the rear of the Ratte might have made this unrealistic. A third option would have been a hull-mounted version of the 128mm gun similar to that seen on the Jagdtiger. This would have at least been able to engage nearer targets than either of the other options.
Additional armament would have been spread on and throughout the Ratte. The heavy-machineguns and some of the 20mm guns would have probably been mounted inside ball mounts in the hull of the Ratte. A quad 20mm flak gun could have been mounted on the extremely large top surface of the turret and additional 20mm guns mounted on the top hull at the rear of the Ratte. If they were willing to put up with the exhaust fumes, an entire platoon of Panzergrenadiers could have sat atop the rear hull of the Maus.
While the Ratte was supposedly a 1000-ton vehicle this number was an almost mystically optimistic figure, much like the 100-ton weight intended for the Maus. The turret alone for the Ratte would have weighed more than 600 metric tons. The actual combat-loaded weight of the Ratte would have been closer to 1,800 tons. The speed, range, and longevity of the engines and transmission would have suffered accordingly.
The Ratte was a paper Panzer and as such the only real variants were the two choices of engines.
The Ratte was a very problematic vehicle and the size of the Ratte was responsible for most of the issues it would have encountered on a hypothetical battlefield. A Ratte on the move would have been relegated to fields and countryside because of its road-destroying weight. Without bridges as a river-crossing option, the Ratte would have been unable to cross flooded or deep rivers and scouting parties might have wasted lengthy periods and squandered lives finding a crossing point.
Gunners on a Ratte would have found it awkward to engage targets from close or medium range with even a hull-mounted 128mm gun. Concealing the Ratte from aircraft would have required a blimp hangar or some sort of bizarre camouflage that would make it resemble a building. Such camouflage is feasible, if comical, but would have been useless the first time ground units spotted the Ratte. From that point on the Ratte would have been constantly harassed by fighter-bomber. Even if the Ratte’s 20mm AA guns had managed to drive these off, the Ratte was such an enormous target that high-altitude bombers could have been employed to attack it.
Not everything was bad about the Ratte. Infantry would have been less of a risk than with the Maus because of the number of point defense weapons and the space for infantry to ride on the vehicle’s hull. The Ratte would have likely served as the cornerstone of a unit of traditional military vehicles and these would have assisted in defending it from enemy tanks and aircraft. Enemy armor posed almost no conceivable threat to the Ratte. They might have destroyed things like the AA guns on the turret or damaged radio antennae or weapon optics, but beyond minor damage enemy tanks were toys next to this mammoth vehicle. Enemy artillery was slightly more threatening and became downright dangerous if the Ratte made the mistake of straying within range of naval bombardment.
The greatest strength of the Ratte would have been its ability to single-handedly halt a major enemy offensive. It would have been slow and poor on the attack but the sight of a Ratte looming out of fog on a battlefield would have almost immediately scattered enemy ground forces. If they didn’t flee right away they would have once they realized their weapons were nearly useless against it.
Make no mistake, the astronomical cost of building a Ratte would not have been offset by its strengths. Once deployed and used in combat, it was just a matter of time before enemy aircraft destroyed it. With such poor speed and the limitations of the terrain the Ratte would not have enjoyed the same advantages of a wide open sea as its naval counterparts. The Ratte could have turned the tide of a single battle at the cost of a campaign.