Working to rebuild a historic wharf on Matiu/Somes Island in the middle of windy Wellington Harbour throws up some unusual challenges, including the need to work around its local penguin population, says project engineer Kyle Marshall.
For the past eight months, Kyle and his 15-strong team from Brian Perry Civil have been working on the project with the goal of preserving access to the conservation paradise for another hundred years.
He says before the project started in April, the 116-year-old wharf was in such bad shape that people could see it moving when the East By West Ferry dropped them off to the island.
“When I saw the structural condition of the wharf it was quite clear that it had to be replaced.”
The new 36m-long wharf is designed to be a long-lasting, low-maintenance structure providing continued and reliable access into the future and withstand a one-in-500 year seismic event.
Kyle, 28, says Matiu/Somes Island is one of the most unique worksites he has ever experienced.
“From the top of the hill on the island you get a full 360-degree view of Wellington, on a good day it’s an amazing work location but on a bad day it is extremely exposed to the elements.”
The worksite itself was perfectly sheltered from southerlies however, while the rest of Wellington Harbour would be rolling with waves, he says.
“It’s incredible when you’re working on the wharf and seeing two-metre swells whipping past, but where we’re working on the south side of the island is still nice and calm.”
Apart from the weather, the site presented a range of challenges that made the project unlike any other.
As a scientific and historic reserve home to a variety of native birds, invertebrates, reptiles and plants, the first challenge was to protect the pristine environment of the island and comply with its strict biosecurity standards, he says.
“The island is predator free. It has been for a long time and the Department of Conservation (DOC) want to keep it that way. Every piece of plant, every person, and all equipment that we have brought to the island has had to go through a biosecurity inspection before coming over.”
Kyle says another consideration has been keeping “the locals” on side, as Matiu/Somes Island is home to New Zealand’s biggest colony of Kororā/Little Blue Penguins – the world’s smallest penguin.
On other projects he’s worked on, penguin netting has been used to stop penguins nesting in working areas. However, a different approach was taken on Somes Island, with a Department of Conservation (DOC) ranger living on the island advising the team where the penguins usually nest so they could avoid them.
“We were encouraged to work with the penguins, checking the work areas and plant before work could start each day. If a penguin was found within a work zone, the island ranger was trained to relocate them to safety.”
The ranger was grateful for Brian Perry Civil’s construction of a boat ramp as part of the project, which made it a “huge difference” when launching boats off the island, Kyle says.
To add to the project’s complexity, it also incorporated an element of heritage preservation. The previous wharf, built in 1908, occupied the same site as the island’s first wharf built to complement the quarantine facilities there in 1873. Archaeological remnants of the 1873 wharf survived as cut-off piles protruding from the seabed.
As these represented some of the few heritage features surviving from this era of Matiu/Somes island’ history, the visible piles were cordoned off for preservation. Kyle’s team liaised with an archaeologist assigned to the project to make a record of additional piles encountered during excavations for the new abutment and, where possible, to ensure construction activities did not damage the remnants of the previous wharf.
Apart from the history and the natural elements involved in the project, Kyle says the logistics of working on an island made the site challenging.
To make life easier, a specialist barge with a 150-tonne deck capacity was used to carry all their equipment required, including a 90-tonne crane. The barge was essential to the operation, especially as there was no space to store materials on the island itself.
“With virtually no laydown area, everything had to be transferred to the island at the right time, which meant good planning was essential. We sat down as a team every week to meticulously plan the tasks and make a list of every nut, bolt and tool that was needed.”
Brian Perry Civil always had a transport boat on hand as a safety back-up, while a tugboat towed construction materials over from the mainland on a floating barge.
“It’s not as easy as just going to the hardware store when you’ve not got something you need, everything had to be on site for the programmed tasks.
“The structure, piling and engineering work is all quite routine for me, but the logistics and challenges of working on an island and getting materials there in time for when we need them according to a tight programme I really enjoyed.”
He says the new wharf is going to make a “massive difference” to the ferry’s passengers.
“Our wharf structure makes it so much easier for the public and any visitors to get on and off the island.”
Kyle’s journey into civil infrastructure construction
Before coming to New Zealand from Scotland in 2022, Kyle hadn’t done any marine engineering work. He worked on civil engineering projects in Scotland, after graduating with a master’s degree in civil engineering in 2019, then decided to move to New Zealand to work on a project repairing and upgrading Seaview Wharf in Lower Hutt, after finding out about it from a friend.
“Somehow, I find myself in the position where I’ve been helping with marine projects around Wellington and came to be a go-to person. I’ve been thrown in the deep end, but I feel I’ve definitely developed myself as a marine engineer.
“Civil infrastructure is an industry that is extremely rewarding. As an engineer, you get the opportunity to work on various types of projects. The sense of accomplishment that comes from knowing your work will benefit many people is unparalleled.”