Getting a pipe from one side of a river to the other usually isn’t a big deal. You bolt it to a bridge, or you dig a trench across the bottom, drop the pipe in and cover it back up. It gets a lot trickier when the water in question is the Welland Canal, the shipping channel that lets lake freighters get around Niagara Falls.<\/p>\n
So Niagara Region is going under it. Working with the City of Port Colborne, the city at the canal’s Lake Erie end, the regional government is running two small tunnels beneath the channel. The first one broke through on July 9, and the second has been underway since mid-August.<\/p>\n
I say “tunnels,” but you’d have to crouch pretty hard to fit inside one. Each one’s just under 5 feet (1.5 meters) across and 1,017 feet (310 meters) long, and each one works as a protective sleeve. Once both are done, crews will slide six pipes through them to carry sewage and water across to the other bank, then fill the leftover space with grout.<\/p>\n
I’d imagine the people who run a busy shipping channel aren’t wild about anyone tearing up the bottom of it. Going underneath means the pipes won’t be in the way of anything floating above them. Ward & Burke, the tunneling contractor, had to keep at least 21 feet (6.5 meters) of clearance below the canal bed the whole way, according to Daily Commercial News<\/a>.<\/p>\n The method is called microtunneling, and it’s basically a remote-controlled, scaled-down cousin of the giant boring machines you’ve seen in photos. Generally, hydraulic jacks sitting in a launch shaft shove the cutting machine forward, and crews add pipe sections behind it one at a time, so nobody has to ride along. We’ve covered this kind of machine before, including a 7-foot one that crossed under a Seattle street<\/a> and an 8-foot one pushed through rock under a California reservoir<\/a>.<\/p>\n So what’s the hard part about digging under a canal?<\/p>\n Water, according to Phill Lambert, Niagara Region’s director of water and wastewater services. He told the trade paper the water table put a lot of extra pressure on the machine, and he called handling it “a balancing act.” A tunneling machine in wet ground has to push back against that water with pressure of its own at the cutting face. Get it wrong and the machine can dig out more ground than it’s supposed to, or less, and neither sounds great with a shipping lane above you.<\/p>\n These aren’t straight tubes, either. Lambert said the first drive followed a curved alignment, and one of Ward & Burke’s engineers posted from the site that the alignment includes several vertical curves, one of them an arc with a radius of about 1,970 feet (600 meters). Vertical means the bends go up and down rather than left and right. The machine set off from a launch shaft about 56 feet (17 meters) below the surface, headed downhill and bent its way under the canal to a reception shaft on the other side.<\/p>\n I’d love to tell you exactly how steep that first stretch is and how deep the far shaft goes, but the published figures don’t match (one source gives the grade in degrees and another in percent, and those aren’t the same thing), so I’m leaving them out.<\/p>\n You can’t exactly look out a window 1,000 feet into bedrock, so the crew leaned on instruments. The machine’s position was tracked electronically the entire way, and surveyors double-checked it every 60 meters or so, which is just shy of 200 feet, according to Lambert. That engineer also said his crew was working roughly 65 feet below the water surface while big ships went by overhead. He admitted it feels strange. I believe him. And the machine hit its mark at the reception shaft.<\/p>\n After that first breakthrough, crews pulled the machine out so the contractor could service it and start over, according to Gordon Bell, Niagara Region’s senior project manager on the job. That’s what’s happening now. The second drive started in mid-August and runs parallel to the first. I haven’t found a newer update than the Daily Commercial News report, so as far as I can tell the machine’s still grinding away down there.<\/p>\n The first drive took 33 days. That’s about 31 feet a day on average, and for a machine chewing through bedrock with all that groundwater around it, that’s a pretty respectable pace if you ask me. Reusing it for the second tube makes a lot of sense too, since the crew probably has a good feel by now for how this particular patch of ground behaves.<\/p>\n The first tube will carry four force mains, ranging from roughly 6 to 16 inches (150 to 400 millimeters) across. The second gets a larger force main of just under 20 inches (500 millimeters) and a water main. A force main is a sewer pipe that uses pumps to push sewage along under pressure, instead of letting gravity do the work like a regular sewer line. You need one when the treatment plant isn’t downhill from you, or when there’s a canal in the way.<\/p>\n Those lines will move sewage from the east half of Port Colborne across to the Seaway Wastewater Treatment Plant, which sits on the west side, replacing an east-side force main that’s been in service for more than 45 years. They’ll also shore up the water supply on the east side and serve a new industrial area there, where Asahi Kasei is building a plant to make lithium-ion battery separators. A separator is the thin film inside a battery cell that stops the two sides of the cell from touching each other.<\/p>\n That plant is a big reason the Region fast-tracked the contract. A staff report to Niagara Region’s public works committee said servicing for the site had to be done by the third quarter of 2027. Since then, Honda has indefinitely suspended its Canadian EV investment plans, and Asahi Kasei told CBC News<\/a> in May that it’s still building but now targets commercial production for the first half of 2029. So the pipes will probably be sitting there ready a good while before the plant needs them. Then again, Niagara Region was studying a new crossing here years before anyone picked Port Colborne for a battery plant, so the tunnels arguably would’ve happened either way.<\/p>\n The second drive was due to finish by the end of September, according to Daily Commercial News, and Niagara Region’s project page<\/a> lists June 2027 for wrapping up construction.<\/p>\n Image credit: Courtesy Niagara Region\u00a0<\/em><\/strong><\/p>\n","protected":false},"excerpt":{"rendered":" Getting a pipe from one side of a river to the other usually isn’t a big deal. You bolt it … <\/p>\nThe tunnel bends on the way across<\/h2>\n
The same machine is doing it all again<\/h2>\n
So who needs six pipes under a canal?<\/h2>\n