A $1.2 million fire engine that broke down during a major factory fire in Auckland is off the road again with tyre trouble.
The 21-year-old relief heavy aerial appliance with a 30m long turntable ladder, shared between Auckland City, Parnell and Hamilton fire stations, was deemed not roadworthy after a mechanic discovered misshapen tyres.
The New Zealand Professional Firefighters Union Auckland Local Committee secretary John Waldow said firefighters became concerned when the truck cab started shaking and bouncing during a routine trip at 40km/h.
Waldow said the aerial's two "super single" heavy-load tyres at the front end had become "egg-shaped" under the truck's 23 tonne weight.
"The tyres have gone elliptical," Waldow said.
"As the truck got up to 40km/h it's started to yaw, so the cab started to shake from side to side. Then as you got up to 50km/h it went up and down; the cab starts bouncing.
"One of the officers started to get car-sick, he was changing colour. But we were driving it in the wet and we had a car pull out in front of us. We were like 'woah this isn't good'."
A mechanic told firefighters the tyre "gets a memory" - or a flat spot - from not turning often enough.
"The head mechanic said it shouldn't be on the road, we shouldn't be driving it. If there's a known fault with the tyres and it's causing instability in the vehicle and you have an incident or an accident in that vehicle and you knew about it, you're finished.
"As the driver you are fully liable."
The specialist fire engine is the same aerial driven to a massive factory fire in Henderson in September 2016 but left parked on the side of the road after firefighters discovered the water pump was broken.
In a memo to all fire union members on the NZPFU website the Auckland committee said the tyres were so rare replacements were "apparently unobtainable until August".
Fire and Eemergency New Zealand fire region 1 manager, Kerry Gregory, said it was initially thought replacements would have to come from Japan, but replacements have now been sourced from Australia and the appliance would return to service in a few weeks.
"The truck was bought in 1997 and we do not have a record of what tyres it originally came with," Gregory said.
"The tyres we encountered issues [with] were the only brand available in New Zealand at the time. The replacement tyres coming from Australia are a different brand."
Two tyres are being imported at a cost of about $1000 each.
The appliance has a 30m, or eight-storey high, hydraulic extending ladder.
The Herald on Sunday revealed 10 days ago Auckland firefighters were warned not to drive faster than 100km/h to emergencies because their truck tyres were "not fit for purpose".