The Atlas Rope Ascender – a significant new enabling technology
By Mike Hanlon
February 14, 2007
February 15, 2007 Atlas Devices’ Rope Ascender is a remarkable new tool that enables "reverse rappelling" up buildings and other vertical surfaces at unprecedented speeds. The device, which is the size of a hand-held power tool, can lift a 250-pound load more than 600 feet into the air at nearly 10 ft/sec, all on a single battery charge. Using a patented rope interaction design, the Rope Ascender can pull a fully-loaded soldier up a rappelling line, tow vehicles and even remotely move equipment and casualties. Giving soldiers the ability to scale a building or cliff in only seconds is obviously a capability designed perfectly for Special Opps, and will also find application with the police, fire, rescue and many other endeavours. A fully loaded firefighter could use the Ascender to reach the top of a 30-story building in only 30 seconds, compared to the six minutes or more it often takes to trudge up stairs with 80 to 100 pounds of equipment … just think of all the ways this high-torque pocket power pack can be used. Very exciting!
In November 2004, 2007 Lemelson-MIT Student Prize-winner Nathan Ball and three colleagues entered the Soldier Design Competition sponsored by the MIT Institute for Soldier Nanotechnologies. The competition called for a high-powered device to enable rapid vertical mobility. Ball called the challenge unprecedented, as the original specifications called for a device that weighed less than 25 pounds and could lift 250 pounds 50 feet into the air, in five seconds. "That's more than five horsepower in a 25-pound package," he explained. "That's a power-to-weight ratio higher than a Dodge Viper's—we did the math. To have that much power in that small of a package is a heck of a challenge."
Through a combination of resourcefulness and "the highest-tech equipment we could afford," such as drill batteries and a few high-power density motors, Ball and his colleagues invented a device that could hoist 250 pounds of weight 50 feet into the air in seven seconds—only two seconds slower than the competition's specification.
The novel aspect of the ATLAS ascender is its rope-handling mechanism. Similar to the way an anchor is raised and lowered on a ship, the device relies on the capstan effect, which produces a tighter grip each consecutive time a rope is wrapped around a cylinder. The grip continues to tighten as more weight is applied to the line.
In his design, a standard-sized rope (between three-eighths and five-eighths of an inch) is weaved between a series of specially configured rollers that sit on top of a turning spindle. As the battery-powered spindle rotates, it continuously pulls rope through the device. "We currently have three patents pending for the rope interaction and other iterations on the device" said Ball.
Ball and his colleagues founded Atlas Devices, LLC to develop and market the ATLAS Powered Rope Ascender. He has upgraded the original design, and the device is now powered by high-density, lithium-ion batteries created by A123Systems. Ball said the new power system immediately dropped the device's weight by several pounds and significantly increased its speed.
"The latest configuration weighs 20 pounds and peaks at 10 feet per second," he said. "A123Systems has a 150-foot steam tower we were able to use for testing. We successfully completed a 100-foot continuous ascent to the tower’s platform in 14 seconds."
Ball envisions his invention having practical applications in rescue work, recreational climbing and cave exploration, as well as urban warfare situations. "It can help people complete tasks more efficiently and without depleting energy they would otherwise use climbing ladders and carrying heavy gear," he said.