Concrete may be the last material people associate with floating infrastructure. It’s a specialty of Pacific Marine Construction of Campbell River, B.C., which builds not only floating concrete platforms but is expanding into highly specialized aquaculture barges designed to support West Coast fish farming.
The company has been family owned and operated for nearly 30 years. Current owner Cory Handyside took over the business from his father five years ago. The secret behind making concrete float? A core of durable Styrofoam.
"My father was a carpenter and he once built a floating cabin that was destroyed in a storm," says Handyside.
"He decided he was going to rebuild using concrete and Styrofoam. He did the basic buoyancy calculations for weight and displacement and built his first concrete float on the back of a semi near Nootka Sound. He then backed down to the boat launch and it floated right out to where he thought it should float."
The company has come a long way since then, currently employing 18 to 20 workers. Handyside has built cabins, homes, fishing lodges, tourist accommodations, docks and marinas.
Unlike other companies in the field, Pacific Marine builds all of its floats on a massive 70- by 170-foot submersible steel platform. A 40-ton P&H lattice boom crane lifts supplies and materials from the shore to the platform. Floats are designed in house and poured monolithically, regardless of size.
"We set up the formwork and the initial layout, we tie in the rebar and then include any details," says Handyside.
"We have different methods of supporting the Styrofoam while we pour the concrete. A special concrete additive eliminates cracking and increases the tensile strength by 20 per cent."
No wood connectors are used in the floats, reducing the risk of fire. The use of hot-dipped galvanized metalwork eliminates rust. Because the Styrofoam is fully encased in concrete, no material winds up in the ocean.
The floats typically take 28 days to cure prior to delivery.
"We use a tugboat to tow the platform to delivery sites along the West Coast, as far north as Alaska and as far south as California," says Handyside.
"An air pump system allows us to lower the platform so that the floating structure can be safely deployed for the customer."
With a growing aquaculture industry in the province, Pacific Marine is ramping up its aquaculture business, building full-service platforms for such companies as Marine Harvest Canada, Cermaq and Grieg Seafood.
"They feature six to eight bedrooms for staff, contractors and divers, business rooms, laboratories, dry rooms, generators and desalinators to make fresh water for drinking," says Handyside.
"They include feeding systems worth $500,000 to $600,000. We also add silo bunkers that typically store 300 to 400 tonnes of feed. They're plug-and-play and include all of the electrical and plumbing systems required to begin work. When we deliver them, they're typically anchored 500 to 600 feet from shore and they can begin feeding salmon immediately."
Local sub-contractors are employed for specialty services such as electrical work, communications systems and feeding systems.
The largest feed barge built by the company to date measures 56 feet wide, 132 feet long and stands 40 feet tall, including buildings. The $2-million project was completed this year for Marine Harvest Canada and took four-and-a-half months to build.
Handyside notes that both concrete and Styrofoam have a shelf life of about 100 years, although the floats can be damaged through collisions or human error. A division of the company uses the submersible platform to elevate completed floats to renew paint, provide repairs, or update older aquaculture platforms with newer feeding systems.
As for his father's first cabin built on a concrete float?
"We don't own it any longer, but it's still out on the water in good shape," says Handyside.