The bulletin advises owners and users how to properly calibrate the machine to ensure its stability.

Operator Rick Jaeger-Fozard was killed when a Genie Z-135/70 collapsed at the Kimberly Access yard next to the M25 motorway near Heathrow last summer.

Initial findings of an HSE investigation into the tragedy discovered that the machine may not have been calibrated correctly.

Around 200 similar machines are used on sites around the country.

The HSE alert states: “In order to minimise the risks of overturn, the machine safety devices and sensors must be configured as per manufacturer’s settings.

“The emerging findings from the HSE investigations indicate that the operational stability of a Genie Z135/70 MEWP may be compromised by the incorrect measurement of the boom angle sensors.”

Manufacturer Genie issued its own safety notice last year which can be found here

The HSE added: “The manufacturer’s safety notice should be followed.

“Any machines for which the required calibration checks have not been completed should be removed from service.

“Following the completion of checks, the machines should continue to be inspected, serviced and maintained as per the manufacturer’s requirements.”