ICS 13.340.99                         CHD 8

New Standard from Last Update.

NATIONAL FOREWORD

This Indian Standard (Part 9) which is identical with ISO 22159 : 2007 ‘Personal equipment for protection against falls — Descending devices’ issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on recommendation of the Occupational Safety and Health Sectional Committee and approval of the Chemical Division Council.

Descending devices conforming to this part of IS 3521 are intended to be used in conjunction with an appropriate descent line and other equipment, for example, an appropriate harness or rescue loop and a reliable anchor, to enable a person to descend from one position to another, either on their own or assisted by another person. Typical uses are emergency egress and work positioning. In addition to their primary function of allowing access to a lower point, descending devices and descent lines have a fall protection function.

Descending devices in this part of IS 3521 have been divided into six types. Types 1 and 2 are further divided into four classes.

Type 1 descending devices have an integrated descent line and are intended for multiple evacuations to a safe lower place when users do not need to control their descent speed. The descent speed is automatically controlled, i.e. without the need for intervention by the user.

Type 2 descending devices have an integrated descent line and are manually controlled. They are generally more suitable for single person evacuations to a safe lower place when users may need to control their descent speed and may need to stop somewhere on the descent line.

Types 3 and 4 descending devices are not required to have an integrated descent line. The descent line can be fitted to the descending device on site. These types of descending device are equipped with a manually operated descent control device which, when it is let go, will automatically lock to the descent line and stop the descent (hands-free locking element). In addition, type 3 descending devices will “fail to the locked position” and the descent will stop if the descent control device is moved beyond its descent control parameters, e.g. in a panic situation when the user squeezes the descent control device too far (panic locking element).

Types 5 and 6 descending devices do not have a hands-free automatic locking element or a panic locking element. These descending devices rely on the user to stop the descent manually and to lock off manually, too, typically by wrapping the descent line around the descending device to create enough friction to stop movement. These types are also not required to have an integrated descent line: the descent line can be fittedto the descending device on site.