This page lists plant-related health and safety alerts that have been supplied for public viewing in a bid to share and learn from each incident and prevent re-occurrences.
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Safety & Health
Alert 4 - Crawler Crane Overturns
There have been a number of recent instability issues with telescopic boom-type crawler cranes, with the principle cause of each of the incidents being that the tracks were in the retracted/transport position whilst a slewing activity took place. The failure mode of each incident being that the crane became unstable as there was either insufficient extension or that the boom was elevated, failing to counteract the overturning moment of the counterweights when slewed out of line with the chassis.
Although the HSE has advised that these incidents are not classed as a dangerous occurrence, nevertheless they warrant attention and action to avoid future occurrence. Therefore a safety alert from a manufacturer has been issued to raise awareness and how it can be avoided. Good practice would be that, once in the transport configuration, the crane should not be slewed away from the in-line-with-the-track position. Ideally it should be slew locked ready for manoeuvring or loading onto transport.
Although the cranes affected were from a number of manufacturers, the principle applies to any boom-type crawlers where the counterweights are not removed for transport and the electronic control systems do not recognise the unsafe actions of the operator and the consequent unsafe configuration of the crane.
The manufacturing standards have been met as there is no requirement for identification / automatic prevention of this condition being reached. The safety alert should therefore be generalised as a potential issue with any crane of this type and the recommendations in the Sennebogen document should be applicable to all manufacturers of telescopic crawler cranes.
The Sennebogen-issued safety alert can be downloaded opposite.
Alert 3 - Crushing of mechanic due to falling cab
A mechanic had raised a tailting cab to access the engine area. The configuration of the mast prevented the cab from being safely latched. A leak in the lifting ram caused the cab to lower inadvertantly, trapping and crushing the mechanic who died from their injuries.
The Cadent-issued safety bulletin provides a number of key learning points and actions that should be taken to mitigate future incidents.
Alert 2 - Failure of dipper arm components - Hitachi 360 Excavator
There was a recent failure of a dipper arm on a Hitachi excavator during operation where fracturing due to fatigue occured on the brackets which are fixed to the upper dipper arm and where the cylinder is connected. This lead in this case to the brackets and therefore cylinders becoming separated from the dipper arm, with the arm dropping uncontrollably.
The models affected include:
Zaxis ZX85US-3 ZX85USB-3 all;
ZX85US-5 Serial Number 80030;
ZX85USB-5 Serial number range 100010-100063;
Owners of these machines should carry out inspections of these components and should contact Hitachi Construction Machinery (UK) for further information.
A safety alert from a user can be downloaded opposite.
Alert 1 - Crushing of a worker during vehicle movements
A worker was trapped between a dumper and a delivery vehicle on a Cadent construction site, for which the individual sadly died of their injuries. The Cadent-issued safety bulletin provides a number of key learning points and actions that should be taken to mitigate future incidents.