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SAFERPLAY_The case of one post equipment - Duration: 6:00.
Playground standards (EN 1176-1 &7) draw the attention
of manufacturers and operators for the need of greater care when installing one
post equipment, which is defined as "structurally vulnerable equipment where
the failure of one cross-section (either at the foundation or elsewhere in the
support post) would be catastrophic". This includes not only single post equipment
but also structures where stability is provided by two or a row of legs.
Fatal accidents have happened, in the last few years, in different European
countries due to the collapse of one post equipment. These accidents have been
associated to different or combined scenarios involving: initial choice of
the equipment material (like inadequate class of timber), installation:
construction of foundations or the drainage leading to accelerated rotting
or corrosion; inadequate anchorage. Heavy movement and dynamic loading
without adequate frequency of inspection and maintenance or due to the choice of
impact attenuating materials not allowing for correct inspection of
foundations or due to lack of inspection or maintenance. In this example, this is a
a two legged swing in a school: During a training session for
operational inspectors and maintenance staff- where participants had to use
the equipment -excessive wobbling of the post was detected. After maintenance,
stability was restored. As you can see there was much less wobbling. When
choosing one post equipment, designers should be aware of the higher risks and
take the requirements and recommendations for risk reduction seriously.
The playground standard (EN 1176-1) clearly requires that foundations of one
post equipment shall be accessible for periodic inspection. Furthermore,
suppliers of one post equipment are required
to provide specific instructions for maintenance including a statement about
the need to increase the frequency of inspection and maintenance. The standard
recommends careful planning in the choice and installation of impact
attenuating surfacing if access to the foundation is required for inspection. As
an example, it states that if poured in place synthetic surfaces are used, they
may have to be cut-back and re-laid. The inherent associated costs are implicit.
The standard also recommends additional measures for structural integrity and
stability of one post equipment in terms of construction as it should be carried
out in a way that: minimizes rotting or corrosion in parts relevant for stability,
allows for controlling degradation and the need for decommission, and so
that it can be used without collapse within the foreseen inspection period
when maintained correctly. It also states that during operational and annual main
inspection, special attention should be given to one post equipment. Choosing one
post equipment: risk benefit assessment is recommended. Apart from the higher
risks posed by one post equipment, the need for more frequent technical
inspections and possibly more maintenance may also increase the
potential costs for operators. Before opting for this type of equipment, a
thorough risk benefit assessment should be implemented. For carousels and other
rotating equipment. Where rotating is part of the fun, and adds play value, one
post equipment with a central axis is hard to avoid or the rotating function
would not be achieved. A careful inspection plan and maintenance program
should be developed and implemented as part of risk management. For non-rotating
equipment or where the rotating function does not exist, and a central axis or
another single post is not necessary for the function or play value, designers may
opt for a solution where the risk of stability failure is lower. The same
applies for equipment with legs in a row- either for swings or other equipment:
there are many other framework designs, that allow for greater stability and are
less demanding in terms of inspection and maintenance. So, when "one post
equipment" is not necessary for the play function and has no added play value,
when it is a purely a design or aesthetics choice, the responsibility of the
decision lies on the designer or commissioner and should be taken with
great awareness of the risks. The operator (school manager, city council,…)
will have to deal with the consequences; he should be informed about the risks
and be aware of implications for risk management. Choices of activities and
equipment at design stage, and their layout- siting or placement- will have
an important impact on risk management, as some aspects cannot be changed at a
later stage by operators, in the post occupancy period.
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