Why Darpa reinvented the wheel with its part-Hummer, part-tank creation

Vehicle designers have to make a trade-off between speed on the road and stability in rough terrain.

Cars struggle on mud or sandy slopes, for instance, while tanks are slow and unwieldy on roads. 

Engineers at Carnegie Mellon University in Pennsylvania sought to combine the best of both with their new ‘reconfigurable wheel-tracks’ (RWTs). The shape-shifting mechanisms can transition from round, turning wheels into triangular tracks while on the move – in just two seconds. The technology is described as “potentially ground-breaking” by the project leader, the US Defense Advanced Research Projects Agency (Darpa). 

The wheel-tracks could make military vehicles safer without adding armour, said Major Amber Walker in a Darpa video, by instantly improving mobility on different types of terrain. The demonstration only showed a Hummer with the wheels on tarmac, however. 

It is far from certain that this reinvention of the wheel, which is still in development, will ever reach production. The many moving parts could easily become clogged, and maintenance would undoubtedly be a challenge. The complexity could also make the technology prohibitively expensive.     

It is nonetheless clear that the design could bring major mobility improvements to vehicles in difficult environments, including applications such as search-and-rescue missions. Even if it never hits the road, it may inspire technology that does.