Authorities are struggling with what to do about a second lot of truck brakes involved in serious accidents causing death.
Both NZTA and WorkSafe have known for years that cardan shaft brakes are "tending to fail in certain situations, including when parked on a gradient", as WorkSafe puts it (file image). Photo: 123RF
In recent days the New Zealand Transport Agency - Waka Kotahi (NZTA) has effectively issued a ban from September on Sanwa Seiki truck handbrakes implicated in two deaths, after years of only giving out safety alerts.
But the agency has not banned a much more common type of heavy vehicle handbrake, called cardan shaft (or driveshaft park brake), though these failed on a truck in 2017 and a mini-crane in 2018, in both cases crushing men to death.
Serious accidents stretch back to at least 2012, and there have been safety alerts go out in 2013, 2018, 2019 and last year.
Both NZTA and WorkSafe have known for years that cardan shaft brakes are "tending to fail in certain situations, including when parked on a gradient", as WorkSafe puts it.
The brakes' weakness typically does not show up in the limited tests done during regular vehicle inspections.
A coroner looking into the death of Andy Loving, 63, who was crushed to death by an effluent truck running backwards near Queenstown in 2017, told NZTA to fix this by adding extra brake tests to see if the handbrakes worked in reverse.
The agency has not done so.
But, at the end of last year, it did get some safety tests done on trucks with the brakes.
NZTA did not respond to RNZ's request to release the results of the tests, and said it would address that matter later today.
Do not 'solely rely' on brake
A 2020 safety alert from NZTA said: "Drivers must not be put in situations where a cardan shaft park brake is solely relied on to hold a vehicle".
It said to use chocks under the wheels.
Major rest home company Ryman is caught up in the problems.
Ryman is backing the NZTA brake test study, and has spent $1.1m on training and a slew of other rectification measures after a mini-crane rolled down a ramp, killing its operator, Graeme Rabbits, on one of Ryman's construction sites in January 2018.
Ryman wanted to alert the whole industry to the risks, WorkSafe said early last month, in an Enforceable Undertaking it agreed with Ryman instead of prosecuting the company.
Ryman's research in this country and internationally "has identified gaps in the training and guidance that leave open the risk of future accidents", WorkSafe said.
But these gaps were identified by regulators many years ago.
"The parking brake was totally ineffective," an official investigation into a truck crash in 2012 warned.
And in 2013, NZTA said in a safety alert: "The number of cardan shaft brake injuries by people accidentally releasing handbrakes is increasing.
"If it is not correctly maintained it becomes ineffective very quickly."
'Catastrophic results'
Four years later, in 2017, after the investigation of Loving's death, a WorkSafe manager wrote in an email:
"You will both be aware we have had a few incident [sic] recently where cardan shaft brakes have failed with catastrophic results.
"One of the major concerns that has come out of our investigations to date is that the level of knowledge and understanding of this type of brake is very low amongst the owners and operators."
A further four years on, in 2021, in response to Rabbits' death, there is more of the same, with WorkSafe and NZTA looking to Ryman to fund a $150,000 nation-wide roadshow.
The roadshow was to ensure operators "across several high-risk industries including agriculture, construction, transport and forestry" were aware of the brake risks, the enforceable undertaking says.
RNZ has approached Ryman and the family of Rabbits for comment.
Several industry sources told RNZ that many people still did not know the risks.
They said that experienced truck drivers would be more likely to know, compared with newer drivers - the ones most likely to drive the trucks under-12 tonnes that typically have this type of handbrake.
'Doesn't test the maximum'
The threat of failure rises if the heavy vehicle is on an uneven surface such as gravel, or is being loaded unevenly, such as happened with the effluent truck in 2017, alerts show.
Drivers might not be used to pulling the brake handle on so hard as required with this brake, NZTA warned.
In the 2017 death, the brake would have worked if it had been pulled on one single tooth more, an investigator found.
When a truck or machine goes for its Warrant of Fitness or Certificate of Fitness, inspectors use a stall test on the handbrake, or test it on a bit of a slope.
But NZTA in 2020 said: "The WOF and COF test is the minimum performance requirement but doesn't test the maximum conditions a vehicle may operate in".
The effluent truck in 2017 had just passed its COF.
It could not be put in gear when using its suction, so relied just on the handbrake, though it was on a level surface.
"It would not have been foreseeable that the brake would fail in reverse when the vehicle had a recent COF assessment and functioned at the standard that was
required for a COF," it said.
Coroner Anna Tutton noted "several situations nationwide where a vehicle has 'held' in a forward direction but failed in reverse".
WorkSafe's investigation noted it was possible to get a COF without any test of the handbrake in reverse.
Tutton pushed NZTA to look at testing the handbrake in reverse; the agency agreed to look into it - but also told the court that would be difficult or even unsafe to do.
Today NZTA launches a whole new regulatory top-dog position of land transport director, to which it has appointed its general manager of regulatory services, Kane Patena.
Earlier, RNZ put questions to WorkSafe about Sanwa Seiki brakes.
It replied that "Sanwa Seiki brakes are a type of cardan shaft brake.
"Our safety alert in 2019 about cardan shaft brakes related to all cardan shaft brakes including Sanwa Seiki brakes, although it did not specifically mention them."
However, Sanwa Seiki brakes are not a type of cardan shaft brake.