Q: What are the differences between ascenders and rope grabs?
A: Most products labeled and sold as ascenders, usually work well in other applications that require rope grabs. Conversely most rope grabs can be used for ascending a rope. The key factor and requirement is that ascenders and rope grabs are typically not designed to be shock loaded. Unless authorized by the manufacturer, ascenders and rope grabs should never be used in a shock load scenario. These valuable tools are solely for vertical work positioning jobs and/or pulling tensioned rope within the recommended safety margins of the manufacturer.
The key difference between the act of ascending a rope and simply grabbing and pulling a rope is that ascending is mostly reliant on the use of the large and strong leg muscles. This requires at least one ascender/rope grab to be equipped with a foot loop or some other type of foot interface. Additionally, the skill climbing a rope typically requires an additional rope grab harness component. This allows for the transfer of the climber’s body weight between upper torso and the legs facilitating need to move the foot component up the rope for each additional step.
Most products sold as ascenders have a handle for easier gripping that promotes a more efficient use of the arms in assisting the leg muscles during each upward movement step.
Prusik loops have been used for decades as a means for grabbing and ascending rope. This is a good emergency skill to have, however, for extended rope climbing and rope access work manufacture red ascenders are highly recommended for safe and physical efficiency.
Q: Should ascending skills be required by rescue personnel?
A: The answer to this question is very dependent on the potential rescue environment the personnel are required to perform in. Not all rescue teams need to train or be proficient in descending and/or ascending rope. A good example would be in-house industrial rescue teams that only need to respond to horizontal confined space insipient rescues. However, the moment vertical rescue potentials are presented, acquiring ascending skills should be considered.
Any rope access technician and rescue technicians that are responsible for vertical environment rescues must be vertically mobile. This means they must be able to move up, down, and side to side in a highly practiced and controlled manner.
Q: Can ascenders be used for belaying?
A: Typically, no. Remember, most ascenders and rope grabs are designed for work non-shock load/positioning applications. Devices designed for belaying and fall arrest applications assume some degree of shock loading and these fall arrest devices will employ some aspect of energy absorption and deceleration.
Historically, prusik loops have been used in dual applications in mainlines and belay lines. However, a growing number of vertical training accidents attributed to the use of tandem prusik belays and supported with current and numerous testing strongly indicates that the use of prusiks for fall arrest/belay applications should be discontinued.