Page 1421 - Xmo Strata - Bulletin Archive

Health, Safety & Environmental Bulletin No 527

04 August 2016

MID Collapse

This café sign in North Wales was blown over by the wind;
luckily no one was injured.

On closer inspection it was found that six of the studs
holding the sign had sheared off below the bottom
levelling nut.

There were a number of causes of the collapse:

1. The location of the sign on the north Wales coast and
the flat ground was such that higher wind loads were
likely.
2. The sign had been modified by adding large panels over
the original sign, covering most of the original frame.
This would have increased the weight, surface area and
wind-loadings of the sign.
3. The sign had been bolted onto studs with a significant
gap between the base and the sign footplate. A small
gap is needed to allow the sign to be levelled, but this
larger gap put additional stress on the studs causing
them to flex and eventually sheer.

It is important that when installing pole signs that the
JSA/JHA’s are followed and the baseplate is mounted as
close to the base as possible whilst allowing for the
levelling nuts. If the base is so off level that a significant
gap is needed to level the sign, contact your line manager.

When modifying any signs, wind-loadings should be
assessed, the original panels should always be removed
and replacement panels fitted securely to the structure. If
the structure is damaged or shows significant wear, or is
wood (most likely with fascia or projecting signs) with
>20% moisture content, do not fit the sign – contact your
line manager.