Thanks one and all. Still tough getting downstairs to my actual workroom so been working at the computer desk.
The Maus was intended to punch holes through enemy defenses in the manner of an immense "breakthrough tank", whilst taking almost no damage to any components. The general idea for such a big tank was best summed up by Heinz Guderian, saying that: "Hitler's fantasies sometimes shift into the gigantic".
The complete Maus or Panzer VIII vehicle was 10.2 meters (33 ft 6 in) long, 3.71 meters (12 ft 2 in) wide and 3.63 meters (11.9 ft) high. Weighing 188 metric tons (207 US Tons), the Maus's main armament was the Krupp-designed 128 mm KwK 44 L/55 gun (Hitler thought this gun looked like a toy in the massive Maus so it was to be replaced with a 150mm), with a coaxial 75 mm KwK 44 L/36.5 gun. The 128 mm gun was powerful enough to destroy all Allied armored fighting vehicles then in service, some at ranges exceeding 3,500 meters (2.2 mi).
The armor was substantial: the hull front was 220 millimeters (8.7 in) thick, the sides and rear of the hull were up to 190 millimeters (7.5 in). The turret armor was even thicker, the turret front was up to 240 millimeters (9.4 in) and the sides and rear 200 millimeters (7.9 in). The gun mantlet was 250 millimeters (9.8 in), and combined with the turret armor behind, the protection level at that section was even higher.
With a V12 1,200Hp diesel engine, during actual field testing, the maximum speed achieved on hard surfaces was 13 kilometers per hour (8.1 mph). The vehicle's weight made it unable to utilize most bridges, instead it was intended to ford to a depth of 2 meters (6 ft 7 in) or submerge up to a depth of 8 meters (26 ft 3 in) and used a snorkel to cross rivers. Fording required 2 tanks connected by an extension cord. While the first tank submerged and crossed, the second tank remained on the bank and supplied power to the submerged tank.
Now consider the Ratte or Landkreuzer tank. Designed at 1000 tonnes (1102 US tons), powered by two MAN V12Z32/44 24-cylinder marine diesel engines of 6,300 kW (8,400 hp) each (as used in U-boats) or eight Daimler-Benz MB 501 20-cylinder marine diesel engines of 1,500 kW (2,000 hp) each (as used in E-boats) to achieve the 12,000 kW (16,000 hp) needed to move this tank. The engines were to be provided with snorkels, also like those used by German submarines. The snorkels were designed to provide a way for oxygen to reach the engine during amphibious operations passing through deep water.
The Ratte's primary weapon would have been a dual 280 mm SK C/28 gun turret. This was the same turret that was used on the German capital ship Gneisenau. The guns used for the Ratte would have fired ammunition developed for other naval guns.
Further armament was to consist of a 128 mm anti-tank gun of the type used in the Jagdtiger or Maus, two 15 mm Mauser MG 151/15 autocannons, and eight 20 mm Flak 38 anti-aircraft guns, probably with at least four of them as a Flakvierling quad mount. The 128 mm anti-tank gun would have been mounted within a smaller secondary turret at the rear of the Ratte,