sentences:  The main armament could have been mounted without a rotating turret.Such a configuration would have allowed the P. 1500 to operate in a similar manner to the original 800mm railroad gun and Karl 600mm self-propelled mortars, launching shells without engaging the enemy with direct fire.Development of the Panzer VIII Maus had highlighted significant problems associated with very large vehicles, such as their destruction of roads/rails, their inability to use bridges and the difficulty of strategic transportation by road or rail.