Rapid Ascent for Rescue and Assault Teams
The students founded a company, Atlas Devices, based in Cambridge, MA, to commercialize the device, which is about the size of a power drill. Nathan Ball, Atlas's chief technology officer, says that such a device has never been made before because the batteries and motors needed to generate enough power for rapid rope ascents have been bulky and heavy. Atlas's 20-pound machine uses a fast-charging, high-power-density lithium-ion battery made by A123 Systems, based in Watertown, MA. (See "More Powerful Batteries.") To use the device, a soldier or rescue worker wraps a rope around its cylinder and clips it to a harness worn around the waist.Source.
The next time I find myself several hundred feet down a vertical cave, I will no doubt use jumars to ascend. But I'll be wishing I had something faster.