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Controlled Descent With Radially Compressive Rope

0911 10 lg

A rope-descending technique known as fast-roping was first used in combat by the British during the Falklands War, although American troops used an earlier version throughout the invasion of Normandy. Employed to deploy personnel from a helicopter, building, cliff, etc., where a fast descent is necessary, fast-roping is slightly different from traditional rappelling. Fast-ropers are not attached to a rope with a safety harness or carabiner, but instead use their gloved hands and booted feet to slide directly down the rope to their point of contact. The Naval Air Warfare Center Aircraft Division (NAWCAD) Patuxent River, Md., has developed and patented a revolutionary rope design called a radially compressive rope assembly (RaCRA) that compresses with the grip of a hand for better control over the rate of descent.

Typically, in a traditional rope design, a fast descent with a tight grip creates a large amount of friction, which generates great heat for the user and can cause injuries such as rope burns, as well as fractured bones, twisted ankles, and internal injuries from loss of grip. For the RaCRA, a tighter grip translates into an indent in the rope, which provides a better hand-holding block instead of producing more friction. A major concern of fast-ropers, as well as rappellers, is descending a fast-rope during bad weather conditions such as snow, rain or wind because of a slippery or swinging rope. Grease or oil present on the rope, hands, or body can also complicate the effective use of ropes and result in injuries. For first responders, Special Forces, Coast Guard, law enforcement, homeland security personnel, and recreational climbers, the RaCRA provides lower friction burn injury rates, better control of the speed of descent, as well as extremely rapid engagement and disengagement, thus allowing multiple users to descend in a short period of time. It provides a much better grip even in wet, oily or other adverse conditions, and provides a method to modify the rope assembly’s weight to accommodate the various wind conditions at rope deployment locations—allowing the rope to hang vertically without motion, thus providing additional safety to roping operations.

The Navy’s RaCRA maintains the speed of a traditional fast-rope but with more control for better safety, and it has the potential to revolutionize the military, search and rescue, and recreational climbing industries.

The RaCRA is part of the Naval Air Warfare Center Aircraft Division’s patent portfolio and is available for licensing.

For more information, contact the Naval Air Warfare Center Aircraft Division at 301-342-5586.

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