Pacific National did not demonstrate that the load restraint system provided by demountable cradles carrying jumbo coils was safe and fit for purpose.
Pacific National have indicated that they believe, based on calculations and measured data, that their jumbo coil carrying demountable cradles provide, at minimum, restraint capable of resisting about 0.75 g acceleration. This was greater than the actual accelerations measured by instrumentation during operation, at about 0.3 g typical (0.372 g maximum peak).
Therefore, Pacific National stated that the level of load restraint offered by current demountable cradles demonstrates that they sufficiently restrain jumbo coils against lateral accelerations and prevent coils from moving and falling during transit.
The ATSB acknowledges that Pacific National have provided a demonstration that the demountable cradle design is safe and fit for purpose.
The ATSB recommends that Pacific National review the load restraint system provided by the demountable cradle design to demonstrate that they sufficiently restrain jumbo coils against lateral accelerations and prevent coils from moving and falling during transit.
Pacific National have indicated that they believe, based on calculations and measured data, that their jumbo coil carrying demountable cradles provide, at minimum, restraint capable of resisting about 0.75 g acceleration. This was greater than the actual accelerations measured by instrumentation during operation, at about 0.3 g typical (0.372 g maximum peak).
Therefore, Pacific National stated that the level of load restraint offered by current demountable cradles demonstrates that they sufficiently restrain jumbo coils against lateral accelerations and prevent coils from moving and falling during transit.
The ATSB acknowledges that Pacific National have provided a demonstration that the demountable cradle design is safe and fit for purpose.
Pacific National: initial response
Pacific National provided a response to the safety recomendation, which included an offer of a meeting between Pacific National representatives and the ATSB. The ATSB accepted this offer and the meeting occured on 25 March 2021 with a commitment to provide follow-up action.
Pacific National: meeting outcome
Following on from our teleconference on Monday, we would like to offer the following: Safety Recommendation (RO-2018-008-SR-042).
Pacific National are committed to providing the following with regards to Coil Restraint by the agreed timeframe of the 26 April 2021:
Pacific National briefing: Demonstration of load restraint
Pacific National engineers briefed the ATSB on the results of further work. The briefing addressed the four items indicated in correspondence dated 30 March 2021. Pacific National have indicated that they believe, based on calculations and measured data, that their jumbo coil carrying demountable cradles provide, at minimum, restraint capable of resisting about 0.75 g acceleration. This was greater than the actual accelerations measured by instrumentation during operation, at about 0.3 g typical (0.372 g maximum peak). Therefore, Pacific National stated that the level of load restraint offered by current demountable cradles demonstrates that they sufficiently restrain jumbo coils against lateral accelerations and prevent coils from moving and falling during transit.
On 18 September 2020, Pacific National advised that they have adopted additional containment strategies and continue to look for opportunities to mitigate the risk of a load shift event, for the transporting of steel jumbo coils. Tasks undertaken include:
The ATSB acknowledges the proactive safety action taken by Pacific National. However, it is noted that the focus is on the containment (mitigating the consequence of movement) of jumbo coils rather than restraint (preventing movement from occurring). Pacific National should consider the requirements for the restraint or containment systems and how they are met by the demountable cradle design.
The ATSB is issuing the following recommendation.
