Industry alert: Risk of cracks in perforated chassis rails
Waka Kotahi NZ Transport Agency has issued this industry alert to warn heavy vehicle specialist certifiers and heavy vehicle service providers about the risk of cracks forming in perforated chassis rails.
Industry alert: Risk of cracks in perforated chassis rails [PDF, 737 KB]
Key points for service providers
Heavy vehicle service providers should make sure:
- chassis rails are inspected at every opportunity, especially near load anchor points like log bolsters or container twist locks, and mounting points for other heavy equipment like hi-abs or cranes
- any repairs are completed according to the manufacturer’s instructions, where available
- any modifications meet the applicable certification requirements.
Key points for certifiers
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Make sure the HVEL certification (LT400) for a log bolster attachment confirms the chassis rating remains valid, or a new chassis rating and HVEC certification (LT400) must be issued.
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Consider all conditions of loading in your assessment, including unusual conditions such as side loading from the towing connection or a ‘piggybacked’ trailer.
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Follow good design practice by assessing critical areas, for example avoiding points of high stress concentrations (refer to Appendix B of AS3990-1993 for more information).
Industry alert: Risks associated with trunnion pin type suspension systems
Waka Kotahi has issued an Industry Alert for trunnion pin type suspension systems.
The Industry Alert provides information about the risks associated with repair or refurbishment of trunnion pin type rear suspension systems common to many heavy vehicles.
An incident where the trunnion pin was ejected from a heavy vehicle suspension causing fatal injuries was investigated by the Police Commercial Vehicle Safety Team (CVST). The Police investigation and report in 2019 found that the incident was mainly caused by the trunnion pin breaking. In addition, the overhaul techniques and replacement parts used during a recent refurbishment of the truck’s rear suspension assembly were of concern.
The industry alert is aimed at heavy vehicle service providers and heavy vehicle operators to ensure all repairers of heavy vehicles are aware of this issue.
The key points of the alert
Service providers and vehicle operators should:
- understand the risks of reconditioning this type of trunnion pin suspension system
- only use Original Equipment (OE) trunnion pins and trunnion housings purchased from a reputable supplier for this type of suspension system
- ensure that these suspension units are repaired according to the manufacturer’s instructions by suitably qualified people.
Read our Industry alert: Risks associated with trunnion pin type suspension systems [PDF, 650 KB]
