What is the largest tank?
Panzer VIII Maus
The principal problem in the design of the Maus was developing an engine and drivetrain which was powerful enough to adequately propel the tank, yet small enough to fit inside it — as it was meant to use the same sort of "hybrid drive", using an internal-combustion engine to operate an electric generator to power its tracks with electric motor units, much as its Ferdinand Porsche-designed predecessors, the VK 3001 (P), VK 4501 (P), and Elefant had. The drive train was electrical, designed to provide a maximum speed of 20 kilometres per hour (12mph) and a minimum speed of 1.5 kilometres per hour (0.93mph).[3] However, during actual field testing, the maximum speed achieved on hard surfaces was 13 kilometres per hour (8.1mph) with full motor field, and by weakening the motor field to a minimum, a top speed of 22 kilometres per hour (14mph) was achieved.[4] The vehicle's weight made it unable to utilize most bridges, instead it was intended to ford to a depth of 2 metres (6ft 7in) or submerge up to a depth of 8 metres (26ft 3in) and use a snorkel to cross rivers.