BREAKWATER BUILD: The 220 metre inner breakwater was built in the 1880s using large concrete blocks put in place by crane. The new repairs focus on a 125 metre section.
Photo credit: Tairāwhiti Museum
The repairs and rebuild of the inner breakwater at Eastland Port start this week, and will reinforce a structure that was built more than 100 years ago. The project is expected to take eight months in total, completed in two stages over this summer and the next.
The inner breakwater is made from large concrete blocks designed to protect the inner harbour from big swells and waves.
It was constructed in the late 1880s, with a purpose-built concrete block-making plant operating on what is now Wharf 8. The blocks were then carried along a railway line and put in place using a large crane (pictured).
Cracks have begun to show due to wear and tear of the structure. Temporary repairs have been done over the years, the most recent being some minor repairs in early 2018.
“The repairs and rebuild were always planned, however the proposed extension on Wharf 8 will be built over a portion of the inner breakwater, so the extent of this repair has been reduced,” said Eastland Port asset manager Jamie Gallacher.
The Wharf 8 extension is part of Stage 2 of the Twin Berth project, which will allow two 185-200 metre long ships to berth at once. Stage 1 covers the rebuilding of Wharf 7 and the slipway, and will begin in the coming months. A resource consent application will be lodged for Stage 2.
Meanwhile, work on the inner breakwater will take place over the summer months when the swell and winds are more favourable.
“The safety of our contractors comes first and work will not be carried out unless the conditions are right, based on daily reports from Met Ocean,” said Mr Gallacher.
“The work will secure and strengthen the existing structure. It’s not an easy thing to repair and it took a lot of collaboration with the Port, our designers and the contractors to come up with a solution.
“First we’ll patch up all the cracks and voids with grout and concrete, then we’ll install steel dowel bars around the perimeter of the structure which will provide reinforcement and extra strength to the existing inner breakwater.”
The structure will then be capped with a reinforced concrete slab using locally sourced MateenbarTM from Pultron.
Two contractors are carrying out the work, with Gisborne’s Ritchie Civil doing the concrete work and a specialist driller coming from Palmerston North to install in the dowel bars. The final stage will be the addition of the concrete capping slab which will sit on top and securely tie everything together.
The repair work won’t affect access to the harbour for boaties and the public, and people can follow Eastland Port on Facebook for updates.