RR1085 – Exploring the human and physical factors associated with telescopic handler overturning risks

A combination of machine instability and various human
factors elements are important precipitating factors in
telescopic handler overturn incidents. Industry guidance
makes a number of assumptions about the impact of
operator “knowledge gaps”, however the link between
operator knowledge gaps and overturn risk is, at present,
hypothetical and remains empirically untested.

This study was done to identify:

  • the full range of human factors issues that might
    potentially contribute to telescopic handler overturn
  • the human factors issues that appear to be most
    important in terms of overturn risk and
  • key operator knowledge gaps that could increase the
    probability of an operator overturning a machine.

The research indicates that a machine is more likely to overturn when its boom is raised and /or extended. Overturn
incidents are also strongly related to lateral (in contrast to
longitudinal) instability. As some operators were not aware
of the overturn risk related to lateral instability, this implies
the possibility of a knowledge gap among operators.
Weaknesses in training and site management/supervision
are also likely to increase overturn risk.
The installation of lateral instability warning technology
could reduce overturn risks by warning operators of
dangerous situations before a critical threshold is reached.

  • Full report

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Article source: http://www.hse.gov.uk/research/rrhtm/rr1085.htm