Police have praised two Otago families for fighting for years to find out what caused a truck crash that killed two men.
Wayne Brenssell and Toby Waitokia were killed when their truck rolled over on a bend on the Waikaka Valley-Tapanui State Highway 90. Photo:
New coronial findings have exonerated the driver and found parts of the truck-trailer were cracked and unsound.
Wayne Brenssell and his passenger Toby Waitokia were killed when their truck rolled over on a moderate bend on the Waikaka Valley-Tapanui State Highway 90 in December 2013.
It was loaded with concrete panels but the A-frames supporting the panels were old and cracked. The coroner is recommending tougher checks on how A-frames are designed and made.
Dale Waitokia and Shona Brenssell fought to overturn the first coronial findings. Waitokia said it was "bittersweet" to achieve this, given how long it had taken.
Police acknowledged the determination of the families.
"This has been a hard and long road for the families to get to this point," Detective Senior Sergeant Malcolm Inglis said.
"They were determined to make sure they got the answers as to what caused this crash and took the lives of their loved ones."
After hearing from more crash experts, police then went back to the Solicitor-General recommending a second coroner's hearing.
Coroner Ryan in the new finding said publicity after the first inquest was that, on evidence, the crash was likely caused by Brenssell braking.
"I agree that it is inaccurate and unfair to state that the braking input by Mr Brenssell was the cause of the roll-over," the coroner said.
Brenssell was "very experienced and cautious", but unused to an air suspension trailer.
He only braked mid-corner because of how the trailer, slightly overloaded with concrete panels, with cracked A-frames, and high centre of mass, behaved on the uneven highway, the finding said.
All these four factors contributed to the crash.
The driver's was a "single non-intuitive braking response".
However, lack of evidence gathered at the crash site hampered drawing unequivocal conclusions.
There was no data recorder on the truck, comprehensive crash photographs were not taken, and the state of the A-frame steel and role of the air suspension were not known in detail.
"The steel A-frame supports for the concrete panels on the truck were found to be structurally compromised due to age and extensive use," the coroner said.
"Pre-existing cracks were found in the A-frames, likely due to fatigue under dynamic loading. Cracks were also found in repair welds.
"After the crash they were found to be almost completely disintegrated.
"Concerns were therefore raised that the A-frames may have collapsed at the critical point where the truck entered the moderate right-hand bend, causing a shift of weight on the trailer, which in turn initiated the roll-over sequence."
The coroner is recommending tougher checks on how A-frames are designed and made.
This "may help reduce the chances of further deaths occurring in similar circumstances", Coroner Ryan said.
It will be up to the Transport Agency and Ministry of Transport whether to follow this recommendation to require certification of the frames by engineers.