In 1985 the US pulled the plug on a computer-controlled anti-aircraft tank after a series of debacles in which its electronic brain locked guns onto a stand packed with top generals reviewing the device. Mercifully it didn't fire, but did subsequently attack a portable toilet instead of a target drone. The M247 Sergeant York (pictured above) may have been an embarrassing failure, but digital technology and artificial intelligence (AI) have changed the game since then. Today defence contractors around the world are competing to introduce small unmanned tracked vehicles into military service. Just like an army on the move, there are contrasting views about how far and how fast this technology will advance.

It has been dubbed the first'sports tank', boasting supercar performance on tank tracks. Originally developed to help to military avoid IEDs, the Ripsaw'sports tank' has become a hit with car enthusiasts. Now, a new version has received a huge overhaul - and has been dubbed'the most obnoxious vehicle ever built'. The newest incarnation, the EV3-F1, is'the most extreme and most terrain dominant Ripsaw ever developed,' the firm behind it says. The Ripsaw, developed by twin brothers Mike and Geoff Howe, both 40, from Maine-based company Howe and Howe technologies, has been around for several years in various forms.