The cause of the third largest fire in New Zealand in the Nelson Valley of Doves has been confirmed as plow-plow sparks.
Chief Fire and Emergency Officer Nelson-Tasman Jan Reed said Tuesday that an investigation revealed that the fire accidentally caused a farm contractor to use a rock paddle disc plow.
The report reveals that sparks from stone or metal to metal contact ignited dry grass in the paddle of the Pijon Valley, 30 kilometers southwest of the city of Nelson, on February 5 this year.
It quickly spread to the steep hill of young pines. The fire in the Piggy Valley has burned out of control for days, covering more than 2,300 hectares of forest, property and pasture. The three-bedroom house and shed were destroyed in the blaze.
* Nelson Contractor Continues Plowing Discs at Dove Valley Fire Site
* Nelson Fire: Authorities look to reduce the risk of agricultural fires
* How to prepare your home if there is a fire
"This fire proves that, in extreme weather conditions, seemingly daily rural activity can end up causing widespread damage," Ride said.
Forest Fire Investigator Jamie Cowan's report said the inspection of the paddle where the blaze started showed 18 significant stone blows, some with "a significant amount of steel smeared on the rocks".
"I was surprised that it was rock-cut, it was so rocky," Cowan said in his report.
There were also marks on at least one of the metal scrapers on the plow used to keep the discs free of debris, indicating that he was in contact with the disc during its operation.
The report states that the contractor who discovered the paddle noticed smoke from the area he had plowed about two minutes earlier. He tried to put out the fire with the discs and extinguishers, but it was too hot.
He had no cellphone reception in the paddle, but by the time a passerby came out he said he had already called 111.
"I am convinced that this fire is caused by the work of the discs in a very rocky ground on a very hot day," Cowan concluded.
He said drives should be considered a low risk of potential ignition in most circumstances, but in extreme fire conditions should be subject to "trigger points" to identify when the risk is high and operations should stop.
Cowan also conducted fire and emergency investigations in NZ. in the Nelson fires that erupted during the fire in the Pigen Valley – on Rabbit Island on February 6 and on Iva Road in the city of Nelson on February 8. He discovered that both were deliberately lit.