Black Rock

In the 1970s, the U.S. military started developing a next-generation heavy tank with maximum crew protection. The ammunition was located separately from the crew in different parts of the hull, and the designers planned to equip the vehicle with advanced electronics and an automatic loading system. During development the available technologies were found to be insufficiently reliable. They were too likely to malfunction and no duplicate manual systems were planned other than periscopes. The tank's concept was clearly ahead of its time, and because of the technical limitations the project was closed before a prototype was built.