26.07.2006

Stability of ladders

The British Health and Safety Executive has funded and published a report
entitled "Evaluating the stability requirements for mounting and dismounting
from the top of leaning ladders".

The aims of the project are summarised as:

  • To evaluate the stability demands placed on an un-tethered, or partially
    tethered, ladder by typical users using the ladder to access high surfaces.
  • To determine whether conventional ladders or ladders and stability devices
    can meet these needs and so provide a safe working environment.
  • To attempt to offer a means to quantify any modification which may be
    required to conventional equipment in order to meet the user demands.
  • To provide an evidence-based answer as to whether this practice is
    appropriate or not.
  • To provide information which will help shape the policy on working at height
    so as to only permit safe practices.
  • Ultimately, to reduce the number of accidents and associated injuries.

This project set out to measure the performance of, and provide empirical data
on, the level of safety provided for users of leaning ladders when they mount
or dismount at the top of the structure. In so doing it has explored the
variation in the safety demand made by different mounting techniques and has
quantified by how much the safety of the ladder system is challenged by such
techniques.

In the same manner as provided for stability devices, minimum acceptable
stability values have been indicated by the provision of a stability threshold,
as well as simple test techniques which can assess the performance of ladders
or ladder products which aim to improve stability for ladders used in this
fashion. This tool offers the capacity for ladders (or ladders and stability
devices) to be categorised by the level of safety they offer. Clearly, an
initial application could be the identification of those interventions which
offer the same, or less, levels of safety as employing a traditional 'naked'
ladder as well as those which bring genuine benefits.

Whilst this may initially seem challenging and commercially potentially
damaging, on closer consideration this is not substantiated. Understanding and
quantifying the demands of the user, and providing products which meet those
demands brings advantages to all the stakeholders. Users, clearly, gain
immediate safety benefit and can trust that ladder systems will provide
reliable support for the activities they wish to undertake. Ladder
manufacturers can review current products and identify means to meet any
performance shortfall or make recommendations as to appropriate applications
for given models, thereby constraining their liability. Device manufacturers
will be able to design more effective products and will have firm guidelines
for quantifying performance. These devices may well have commercial potential
in formal relationships with ladder manufacturers. Employers and safety
practitioners will be able to prescribe appropriate equipment and work
strategies ­ specifically identifying when ladder systems can not provide
adequate stability. Lastly, enforcement agencies will have
a means of determining when individuals may have been undertaking tasks outside
of the 'reasonable' domain and, as such, may account for liability themselves.
In theory, at least, this offers tangible progress in making ladder use safer.

The main immediate conclusion from the applied research conducted is that it is
unlikely that an un-tethered, naked, ladder can provide sufficient stability to
resist the demands of reasonable users trying to mount or dismount at the upper
reaches.

This clearly reinforces the need to tie off ladders in use, or to employ
devices which will enhance the stability in a manner that will demonstrate
compliance with the requirements of the four stability indices described in
this report.

More info


AplusA-online.de - Source: Health and Safety Executive