Location:
New South Wales, Australia
Date/Time:
Friday, November 27, 2020
Work Area:
Operator and Assistant Platform for Steriline Hide Puller
Incident Description:
An uncontrolled fall of the main cylinder supporting the carriage with Driver and Passenger platforms while not in production. The fall was from waist height (approximately 1m).
Diagram/Photo:
Immediate Action:
- The cylinder was assessed for failure.
- The hydraulic connection fitting between the cylinder body and the counterbalance valve manifold had failed - circled in yellow.
Initial Learnings:
- The cylinder is prevented from falling by this counterbalance valve manifold block and rigid connection. This prevents a platform falling from a ruptured hydraulic hose. If the hydraulic connection fitting fails – the platform will fall.
- Steriline Hide Pullers have used this style of arrangement from very early machines (circa 1970’s) and this may affect machines in service. Regular replacement of the hydraulic connection fitting is recommended.
- The failure mode for the hydraulic connection fitting is cracking and splaying of the swivel nut.
Further Action:
- Liaison with client investigation team and the OEM cylinder manufacturer.
- Immediate inspection of the coupling between the cylinder retract port and the custom manifold containing the counterbalance valve.
Action by All Sites
- Identify hydraulic cylinders in service to the Steriline Hide Puller – visually confirm the condition of the hydraulic connection fitting. Refer to Technical Bulletin TB20- 13 for more complete information before any intervention.
- Secure replacement hydraulic connection fittings to replace existing.
- Implement an inspection program for this critical part of the cylinder deployed into rise and fall platform applications. Label the inspection and record it as a regular maintenance inspection within the Maintenance Management System (MMS).
- Typical cylinder life can be as much as 750,000 cycles before a rebuild is necessary. Replacing seals after 2 years is not uncommon. This is dependent on application, environment, and maintenance practices. As such a recommendation from Steriline is replace this hydraulic connection fitting every 2 years or at time of Carriage Cylinder replacement or refurbishment.
More Information:
Please contact Peter Jaensch Ext.# +61 8 8398 3133
Download the official printable copy of this SIA with further information