Genie Z135/70 Mobile Elevated Work Platform (MEWP)

Health and Safety Executive - Safety alert

Department Name:
Field Operations Directorate/ Construction Sector

Bulletin No:
FOD 1 - 2014 REV 1

Issue Date:
March 2014

Target Audience:
, Construction, Engineering, Entertainment and Leisure, Manufacturing (general), Others

Key Issues:
An operator died when a Genie Z135/70 mobile elevating work platform became unstable and overturned whilst it was working at or very close to its maximum height.
In order to minimise the risks of overturn, the machine safety devices and sensors must be configured as per manufacturer's settings, as prescribed by the manufacturer in their Safety Bulletin 130005 dated 29th July 2013. HSE recommends confirmatory checks of the calibration before platform elevation.


The purpose of this safety alert is to advise owners and users of steps to be taken to control risks associated with the Genie Z135/70 Mobile Elevated Work Platform (MEWP) following preliminary findings for a machine overturn. More information may follow in due course.

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.


In order to prevent the Z135/70 model machine operating outside its stability limits, the on-board control system monitors the elevation of the secondary boom to prevent it from telescoping outwards until its elevation is sufficient, as required by the manufacturer (greater than or equal to 75.5°).

The MEWP's on-board control system relies on the correct setting of the elevation of each boom to maintain the effective operational stability of the machine.

Genie, the manufacturer, issued a Safety Notice on 29th July 2013, which required the immediate removal of all Z135/70 MEWP's from service until the listed inspections therein had been performed.

Action required:

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.

Work regarding the manufacturer's safety notice should only be carried out in accordance with the recommendations in the machine service manual ie on firm level ground, with suitable environmental conditions etc.

Following any recalibration, an inclinometer should be used at ground level to confirm the calibration of the angle sensors. This check should be completed before anyone operates the machine in an elevated position using the platform controls.

Re/calibration is considered to be outside the scope of routine pre-delivery or operator checks and should only be undertaken by someone who is competent to do such work.

Relevant legal provisions:

  • Sections 2 & 3 of Health and Safety at Work etc Act 1974
  • Regulations 5, 6 & 20 of Provision and Use of Work Equipment Regulations 1998


Further information:

General note:

Please pass this information to a colleague who may have or use this equipment.

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