P 1000 Ratte

By Christian Ankerstjerne

Introduction

The Second World War was the war which took the tank out of its infancy, and explored and matured the concept of a heavy armoured combat vehicle. As part of this process, as with any design process, there were many experiments and dead ends which today seem too far-fetched to take serious. For example, if a military contractor would submit the idea of a flying tank with discardable wings, it is unlikely that they would ever get another government contract. In the early thirties, however, Walter Christie not only designed several such flying tanks (most notably the M. 1932), but even got the Soviets to hold trials for it (Zelmov, Pavlov & Pavlov, pp. 36-39).

This is important to understand, as it helps accept the mindset which would allow a design like the P 1000, rather than just rejecting it as a hoax. In Germany, a large number of ideas were submitted for review from both the front, from weapons manufacturers and even the review board itself (Jentz & Doyle, p. 20-1). With a large number of more or less rediculous suggestions, some were bound to attract to attention.

Development History

One of these ideas was the P 1000. Krupp's special representative of submarine design, engineer Grote, submitted a scetch to Hitler (who did take some interest in the project) on 23 June 1942 (Spielberger & Doyle, p. 136; Hahn, p. 91), with the following specifications:

Proposed technical details for the P 1000 Ratte. (Spielberger & Doyle, p. 136; Hahn, pp. 91-92)
P 1000 Ratte
Armament
  • Dual 28 cm S.K.C/28 naval guns
  • 128 mm gun
  • Eight 20 mm anti-aircraft guns
Length
  • Without guns: 35 m
  • With guns: 39 m
Width 14 m
Height 11 m
Weight
  • Armament: 300 t
  • Armor: 200 t
  • Frame: 200 t
  • Track: 100 t
  • Automotive components: 100 t
  • Total: 1000 t
Track contact length 21 m
Tracks Three 1.2 m wide tracks on each side
Engine MAN V. 12Z32/44 (8500 h.p. at 600 rpm) or eight Daimler-Benz Schnellboot engines (16 000 h.p. at 1650 rpm)
Ground pressure 0.54 kg/cm²
Maximum speed 40 km/h

The main armament would have been of the same type as on the Gneisenau battleship, with the difference that the Gneisenau turrets had three guns. The third gun was dropped, because the turret would have to accomodate the ammonition, which on ships is usually stored in the hull and sent the to turret with an ammunition elevator. Furthermore, removing the third gun reduced the weight with almost 50 tons. (Hahn, p. 93)

The guns would have fired ammunition developed for the naval guns, which included both armour-piercing grenades (with 8.1 kg of explosive filler) and high-explosive grenades (with 17.1 kg of explosive filler). (Hahn, p. 93) The project never materialised, but did lead to the concept of a tracked 1500 ton self-propelles 800 mm gun, which was to have had to secondary 150 mm gun turrets. (Spielberger & Doyle, p. 136, Hahn, p. 91)

Because the concept of the P 1000 is very intrigueing due to its massive size and armament, and because it is difficult to find any information about the vehicle (especially in English), the vehicle has acheived almost cult-like status on the Internet. Many websites present technical information about the vehicle, but few list any sources and even fewer takes the effort to expand on what limited background is known. As a result, it has become close to impossible to seperate fact from fiction if only using online sources. Spielberger & Doyle and Hahn are the only sources available which appear to base their work on original German documents. Spielberger & Doyle refer to Krupp's submitted design (OKH Auftrag Nr. 30404) and Hahn includes an illustration of Krupp's drawing of the P 1000 (Krupp drawing number E-30404/1 from 29 December 1942).

Turret Production

One of the most popular myths is that a turret for the P 1000 was actually completed, and installed in a costal fortification in Norway when the P 1000 was dropped. While the Germans did construct three fortifications armed with (or intended to be armed with) 28 cm S.K.C/28 turrets, two in Norway (Batterie Fjell and Batterie Ørland) and one in Denmark (Batterie Tirpitz), these were in fact the guns of Gneisenau, which were used after Gneisenau was destroyed (some of Gneisenau's 150 mm guns were re-used in the Danish Stevnsfort after the war). (Asmussen, A)

Weight and Armor Thickness

One interesting aspect of the P 1000 proposal is the weight. As mentioned above, the weight of the P 1000 was intended to be 1000 tons, however this would have resulted relatively thin armour. Since only conceptual drawings exist, it is difficult to calculate the exact size of the intended armour plates. The drawings do indicate a relatively box-like appearence, so assuming the hull itself was a box 35 metres long, 5 metres tall (and not 11 because of the turret and ground clearence) and 14 metres wide seems reasonable. By not including the superstructure in the height, these dimensions should be sufficient for a rough calculation. The turret is not included, because the armament weight of 300 t would have to include the turret armour, since the weight of the guns themselves is only 100 tons in total (Hahn, p. 93). Thus, the 200 tons allocated for armour would have to be distributed on six armour plates:

Steel weigh 7.85 tons per cubic metre, so 200 tons would be equivilant to about 25.5 cubic metres of steel. The average thickness can therefore be calculated as 25.5 = (2 * 5 * 14 * x) + (2 * 35 * 5 * x) + (35 * 6.8 * x) + (17.5 * 14 * x), which gives us a result of approximately 26 mm. The roof plate would likely not require as much steel, as it would also include service and ventilation panels for the engines. Likewise, the floor plate would probably not be as thick as the front, side and rear plates, as was common practise. Nevertheless, an average thickness of 26 mm is rediculously low. For comparison, Gneisenau's turret has an frontal thickness of 358 mm and a side thickness of 190.5 mm, and a deck thickness of 48.3 mm (150 mm for the armoured deck) (Asmussen, B).

If we use the thickness of Gneisenau's turret as a guide, so that the roof and floor is 50 mm thick, the sides and rear 200 mm thick and the front 350 mm thick, we arrive at a total weight of (5 * 14 * 0.35) + (5 * 14 * 0.2) + (2 * 35 * 5 * 0.2) + (35 * 6,8 * 0.05) + (17.5 * 14 * 0.05) = 1041 tons. Therefore, the weight of the P 1000 - if build - would likely have been between 1500 and 2000 tons, with a significantly higher ground pressure as a result.

The nature of the P 1000 idea is probably best summed up by Guderian: Hitler's fantasies sometimes shifts into the gigantic. (Spielberger & Doyle, p. 136)

Additional Reading

Sources

  1. ASMUSSEN, John. Scharnhort & Gneisenau: Gneisenau. Available from Internet: [fetched 2009-07-27].
  2. ASMUSSEN, John. Scharnhort & Gneisenau: Technical Layout - General Details. Available from Internet: [fetched 2009-07-28].
  3. HAHN, Fritz. Waffen und Geheimwaffen des deutschen Heeres 1933-1945 : Band 2: Panzer- und Sonderfahrzeuge, "Wunderwaffen", Verbrauch und Verluste. Koblenz : Bernard & Graefe Verlag, 1987. 320 p. ISBN 3-7637-5832-1.
  4. JENTZ, Thomas L. & DOYLE, Hilary L. Panzer Tracts No. 20-1 - Paper Panzers : Panzerkampfwagen, Sturmgeschuetz, and Jagdpanzer. Boyds, MD : Panzer Tracts, 2001. 60 p. ISBN 0-9708407-3-X.
  5. SPIELBERGER, Walter J. & DOYLE, Hilary L. Special-Panzerfahrzeuge des deutschen Heeres. Stuttgart : Motorbuch Verlag, 1998. 154 p. ISBN 3-87943-457-3.
  6. ZELMOV, Igor, PAVLOV, Ivan & PAVLOV, Mikhail. Kolesno-Gusenichnii Tank BT-2. Moscow : Armada, 1998. 48 p. ISBN 5-85729-014-7.