As a contract highway logging truck was negotiating a corner, the truck’s trailer bunk center pin nut and cotter pin fell out. This caused the trailer bunk to lift off the cup & saucer and slide off the trailer pulling the truck & trailer onto its side.
It was determined that the threads on both the nut & bolt holding the bolster to the trailer were badly worn and only the cotter pin was holding the nut from coming off the bolt (see photos in attached pdf).
Excessive play in the cup & saucer was noticed by the loader operator prior to the incident but the information that could have prevented the incident wasn’t communicated to the driver, or supervisor.
Learnings & Suggestions:
For more information: Dan Pletti, Contract Supervisor 250-720-4253
|Highway logging truck rolls onto its side.pdf|