Crushed finger leads to vibrating post driver
A Marlborough contractor has invented a safe way of driving vineyard posts into the ground.
John Weatherall said losing his right index finger when it was crushed by a hammer-driver got him thinking about safer ways of doing the job.
"I was holding the post while operating the driver when the top 300mm was crushed with my finger amongst it," Weatherall said.
Five years and many refinements later he has a vibrating-press driver he is happy with, developed with Hamilton's Machinery Ltd of Rapaura near Blenheim.
Last week he was using the machine to ram posts at a vineyard being developed for Delegat's Wine Estate, on the Northbank of the Wairau River.
Rather than pounding posts into the ground, his invention uses a hydraulic ram behind a tractor to force them into the soil. If a post strikes resistance, the worker activates the vibrating press.
"As soon as mesh on the plate grips the post you can take your hand away."
Shaking through the post shoves any rocks out of the way.
"The guy working behind the tractor has total control."
If a traditional hammer-driver struck a rock, the worker had to hold the post to stop it skewing out of line which was how he lost his finger, Weatherall said.
Many vineyard contractors used a digger and vibrating press with one worker driving while 2-4 others held posts in place, at least two tonnes of steel poised over their heads.
He tried this system but found it labour-intensive and dangerous so went to Hamilton's machinery to design an alternative.
The prototype vibrating press was shaken apart after only two days but many modifications later, Weatherall is happy with his machine, which he is considering patenting.
- © Fairfax NZ News