“The current market is focused on high-volume, long-term projects and often our smaller ports can’t afford or procure the dredging required to keep them navigable and open for business.”
He said the Johnson Brothers dredge would be specifically designed for low-cost, small-to-medium scale work which was more commercially viable and technically suited for smaller sites.
Johnson Brothers managing director Andrew Johnson said dredging at the country’s major ports was undertaken by “big, foreign companies”.
“Smaller regional ports like this [Whanganui] are right at the bottom of the pecking order,” he said.
“They need something more bespoke and this is the bespoke solution.
“This barge is designed to get material on and get it off.”
The Chronicle reported in February dredging contractor, West Coast Dredging, was unable to safely stabilise its Kawatiri boat at the Whanganui Port after a flood in the Taumarunui catchment last year.
Johnson Brothers was then brought in and contracted to dredge the port channel to 3.0 metres chart datum until mid-2026.
The 38m-long barge will become operational late next year.
Johnson said its production speed would be three times faster than the company’s current barge, which dredged about 130cu m of materials an hour.
“This will be around 390 cubic metres an hour,” he said.
“Because of its bottom-dumping hopper, disposal speed increases as well.
“We think overall efficiencies are around four times what our current machine is.”
A hopper barge has doors on the bottom of its hull to discharge materials.
He said the new barge could also self-discharge to land, which was important when dealing with contaminated materials.
It will be towed by a tugboat.
Q-West Boat Builders managing director Myles Fothergill said the new barge’s grab bucket was similar to the set-up on the port’s original dredge boat, the Wanganui, which operated for about 50 years.
He said bringing a dredge to Whanganui cost between $300,000 and $600,000 “just to mobilise the gear here” and having equipment continuously working around the country would lower those prices.
“Port authorities or companies like ours, that are stressed financially, will be able to find the money,” Fothergill said.
“That is why this has my full support.”
Johnson said dredging “may look easy” but it was a professional discipline.
“There’s a lot involved - hydrographic surveying, how you dredge, where you unload, handling material and setting up the right equipment.
“Having this different methodology and skilled professionals to operate it gives the whole country resilience.”
The Government’s portion of the funding comes from the $30m Coastal Shipping Resilience Fund, established in 2024.
Mike Tweed is a multimedia journalist at the Whanganui Chronicle. Since starting in March 2020, he has dabbled in everything from sport to music. At present his focus is local government, primarily Whanganui District Council.
