East coast-based Howe & Howe started out back in 2001 with an unmanned military vehicle designed for the US Army - the Ripsaw, which at the time was the world's fastest tank. Twin brothers Geoff and Michael Howe continued to build and refine tracked military and civil protection vehicles through the noughties, but first found themselves on the front pages in 2010 when they put tank tracks on a wheelchair to make an extreme off-road vehicle for adrenaline junkies.