As early as June 1937 Hitler demanded more offensive heavy weapons and so the 60cm seige mortar was to become self-propelled (SP). To accomplish this Karl Becker designed the "Karl" Morser (mortar) with a 580 hp DB MB503 V-12 44.5l engine to drive a 124 ton beast! A prototype was built by May 1940 followed by 6 production machines: Adam, Eve, Thor, Odin, Loki, and Ziu. They were initially fitted with the 60cm Gerat 040 L/8.44 and later were interchangable with the 54cm Gerat 041 L/11.5 mortars. The 60cm version handled 2.17 ton projectiles while the 54cm version used 1.58 ton projectiles. The ammo was carried by a seperate vehicle- the Munitionsschlepper from a converted PzKpfw IV chassis which could carry 4 rounds at a time. The rounds were hoisted by external swing arms up to the loading area. In action, they could fire 6 rph! Guns I-IV went to the East Front against the USSR and hit Sevastopol with devastating firepower. These guns augmented the mighty 80cm monster railway gun to smash the fortifications to bits! The US Army later captured guns II and V

http://www.hpwt.de/2Weltkrieg/Karl.jpg http://karl.geraet040.net/thor1942b.jpg http://img.scoop.it/5wo7d4ChSMJPQmgXEuIjqDl72eJkfbmt4t8yenImKBVaiQDB_Rd1H6kmuBWtceBJ http://www.ww2incolor.com/d/65031-6/22