RR657 - Investigation into the fall-arresting effectiveness of ladder safety hoops, when used in conjunction with various fall-arrest systems
Please note, a Safety Notice titled Hooped ladders and the use of personal fall-arrest systems, which provides advice in relation to the content of this report is also available.
It was established in previous HSE research that safety hoops on fixed access ladders (alternatively rendered as caged ladders) could not provide positive fall-arrest capability. The working at height industry has anticipated this finding, which has led to the 'upgrading' of caged ladders by installing fall-arresting systems (FAS) inside the cage. The rationale is that a FAS can make good the cage's fall-arresting deficiency, and since the removal of the cage from a ladder is envisaged as being difficult, hazardous and expensive, it is simpler, safer, and less expensive to install a FAS with the cage left in place.
This approach appears to be commendable, but from a safety and enforcement of legislation viewpoint, it raises some important questions. For instance, if a fall occurs inside a cage whilst a worker is connected to a FAS, will impacts with the cage interfere to such an extent with the operation of the FAS, that the fall will not be arrested? If the fall is arrested, will this done without causing serious injury to the worker?
To address these questions, further research was commissioned to determine what might happen when a worker falls inside a three-upright caged ladder manufactured in accordance with BS 4211 (1994), whilst attached to various types of FAS.
Sixty-eight fall simulation tests were carried out by using an instrumented anthropomorphic test dummy (ATD). In each test the ATD was inserted inside a caged ladder and was attached to a FAS, before being released in one of three falling postures. Seventeen different FAS were evaluated, which included retractable fall-arresters, energy-absorbing lanyards, sliding fall-arresters on rope, rail and cable, and eight different harnesses. The equipment tested was a good, representative sample of that on offer in the UK.
Twenty-three recommendations are made in regard to the findings of this research, including directions for further work.
This report and the work it describes were funded by the Health and Safety Executive (HSE). Its contents, including any opinions and/or conclusions expressed, are those of the authors alone and do not necessarily reflect HSE policy.
Assistance in the use of Adobe Acrobat PDF files is available on our FAQs page.