Descenders, ascenders & back-up devices

Descenders

Descenders are devices which attach the operative to the working rope and allow a controlled descent. They must give the user total control over the descending speed and not cause undue shock loading to the rope during braking.

The descender should be of a type that will:

• Stop the descent if control is lost by the operative.
• Cannot be accidentally detached from the rope once threaded.

Descender devices used in the rope access industry should conform to one of:

• EN 12841 Type C, or
• EN 341 A — the standard for descenders used in rescue systems.

Ascenders

Ascenders are attached to and used to climb the working rope. They should be of a type that:

• Cannot be accidentally detached from the rope once engaged.
• Causes the minimum amount of damage to the rope when in use.

Standards for rope adjustment devices are EN 12841 Type B or EN 567.

Back-up devices

These devices are attached to the safety rope and used in addition to any other equipment engaged on the working rope. Should the operator lose control of a descent/ascent, or the working rope fail, the back-up device should:

• Lock onto the safety rope.
• Help to absorb any shock loading generated without causing significant damage to the safety rope.

The Petzl ASAP fall arrest device meets the requirements of both EN 12841 Type A and EN 353-2 — these being the standards for rope access back-up devices and mobile fall arrestors respectively.