Ladders: Choice of a type fall protection device

The main alternatives for protection of the users of fixed ladders against falling from a height are:

•    Safety cage
•    Guided type fall arrester on rigid anchorage line (fall arrester)

The reference standard is ISO EN 14122-4. 
In case of an overall falling height more or equal to 3000 mm, the ladder shall be fitted with a fall protection device.
What is specified in the standard is that, in general, it is advisable to adopt the safety cage as a protection measure unless this is not possible, for example due to too narrow spaces that prevent its installation. The reason for this choice is related to the fact that an incorrect use of the harness, rather than a structural inadequacy of the ladder, may not provide protection from falling. The safety cage, on the other hand, guarantees permanent safety, regardless of the operator’s behaviour, if it complies with the standard (see figure below). However, a correct use of the harness, associated with a ladder in accordance with the standard and well-trained personnel, is able to arrest the fall more effectively than the protective cage can.
A combination of both safety cage and fall arrester shall not be applied.

For the selection of a suitable type of fall protection device, a risk assessment in accordance with ISO 12100 shall be made. The relevant aspects to be taken into account are, for example, the following:
a)    Access conditions
b)    Total climbing height for a fixed ladder
c)    Quantum of risk of falling and expected severity of injuries
d)    Human aspects
e)    Rescue aspects
f)    Environmental aspects
g)    Frequency of use
h)    Handling of tolls

To ensure, as far as possible, that only authorized and well-trained personnel are allowed to access the ladder and use the harness, the standard requires that such ladders, equipped with a guided type fall arrest device (and without a cage), are equipped with lockable systems to prevent unauthorized and unqualified operators from using them. Below, an example taken from the standard of the device just described, following the main dimensions of the ladders and safety cages.