Two-hundred-and-fifty commercial vessels a month traverse these waters, and currently about four of those are travelling in to Kinder Morgan’s Westridge Marine Terminal and carrying crude oil back out to the Pacific.
The Trans Mountain project and expanded capacity would mean a seven-fold increase in the number of oil tankers coming and going.
The Port of Vancouver is the most active in Canada. Ice free and deepwater, it is home to terminals for all manners of cargo: chemicals, containers, bulk goods, crude oil.
Westridge Marine Terminal is on the south shore in Burnaby, B.C.
A proposed new dock at Westridge Marine Terminal will triple the loading capacity. Aframax-sized tankers are the largest-class vessels allowed in the port at 245 metres in length and with a maximum capacity of 80,000 to 120,000 tonnes.
A new pipeline will further connect the dock to Burnaby Terminal, Kinder Morgan’s tank farm on the far side of Burnaby Mountain Conservation Area.
And the whole Trans Mountain expansion project will see the twinning of an existing pipeline from Edmonton, increasing the full capacity of the system from 300,000 barrels a day to 890,000.
The current cost of the expansion is pegged at $7.4-billion. “It will enable producers to capture an additional $73.5-billion in revenues,” Kinder Morgan said.
Tankers must travel 80 nautical miles (148 kilometres) in and out of these narrow, busy waterways.
For large vessels, an escort is mandatory. Two Seaspan tugboats are tethered to this Aframax-class vessel.
This particular ship is flying a Marshall Islands flag and the international crew may have little experience in these waters. Canada requires locally-trained pilots to be on the bridge of commercial vessels of this size.
In the narrowest part of the route, on the border between Burnaby and Vancouver, two bridges stand 110 metres apart: the Second Narrows Rail Bridge and Ironworkers Memorial Bridge.
The Concerned Professional Engineers, a group with expertise in the bridge's design, notes that, since its completion in 1925, it has been knocked out of commission five times by cargo ships.
Aframax-sized tankers are five times heavier than those cargo ships. The group estimates that such a vessel could knock the rail bridge right off its foundations, carrying it into the Memorial bridge.
Between the Second Narrows and the Lions Gate Bridge, the Vancouver harbour is alive with pleasure craft, container ships, passenger ferries and float planes landing and taking off.
Thirty years ago, larger ships would be allowed in these waters without tugs or modern navigational aids. But the Exxon Valdez disaster changed everything.
In 1989, the oil tanker Exxon Valdez struck a reef in Alaska, releasing 44,000 tonnes of oil. The Canadian government re-wrote the rules to improve shipping systems to reduce risk, improve spill response, and ensure that industry was responsible for the costs.
According to Kinder Morgan, the risk of a major oil spill on this route is small; a once-in-473-years event. To put that into perspective, a “major” spill would be 3,000 times larger than an incident in 2015, where the cargo ship Marathassa discharged more than 2,800 litres of fuel into Vancouver’s English Bay.
But critics say the risk has been dramatically underestimated.
The City of Vancouver, in its submission to the National Energy Board, tabled a report showing the risk of a marine oil spill in the 50-year life of the Trans Mountain expansion project is between 16 and 67 per cent.
In its technical risk assessment for Kinder Morgan, the advisory group Det Norske Veritas pinpointed several locations where oil spills would be most likely to occur, and despite the high traffic, concluded that a collision in English Bay was a low probability.
It determined there is a risk of collision with the high levels of crossing vessel and ferry traffic out in the open waters past Roberts Bank. However, this is where the safety restrictions imposed by the port are reduced.
As the Aframax-class vessel being towed out of port heads past the emerald green point of the University of B.C. lands, one of the tugboats peels off, its escort duties complete.
Out on the Strait of Georgia, the remaining tugboat’s tether is dropped and it paces the tanker for 35 nautical miles of open water.
The tugboat resumes its tethered escort as the two vessels enter the stretch between British Columbia’s Gulf Islands and Washington State’s San Juan Islands.
The tug lowers its speed, winding through Boundary Pass and then Haro Strait. By now, the dark of an early winter evening has set in.
This is the same spot where Kinder Morgan imagined its own “credible worst-case” oil-spill disaster.
As laid out in their 2013 risk assessment, a supertanker veers off course, the remaining tugboat unable to counteract. The vessel crashes into a reef, spilling 103,700 barrels of toxic diluted bitumen.
The scenario envisions a “plausible but highly unlikely” spill with 55 per cent of the bitumen lost at sea. Critics say the percentage of oil lost would be much higher.
As the tanker passes the City of Victoria, a pilot boat pulls up alongside, matching its speed. The Canadian pilots onboard change vessels using a ladder, their duties now complete.
The tanker approaches the final risk-analysis point, the Juan de Fuca Strait at Race Rocks, where marine weather can be strong. A collision with another vessel was determined to be a low probability here, but possible now that the additional pilots have left.
And after a 10-hour journey, this is where the remaining tugboat ends its duties. The tanker must now make its way into the Pacific alone.