 He offered to build a cannon capable of such launches, basically an even larger version of the original HARP design.Saddam Hussein was interested, and work started on "Project Babylon".A smaller 45-meter, 350 mm caliber gun was completed for testing purposes, and Bull then started work on the "real" "PC-2" machine, a gun that was 150 meters long, weighed 2,100 tonnes, with a bore of one meter (39 inches).