Michigan Contractor Cleans Poe Lock Manholes and Drainage System

Michigan contractor battles ice and bitter cold while cleaning the Poe Lock manholes and underfloor drainage system.
Michigan Contractor Cleans Poe Lock Manholes and Drainage System
Tarps shield a 2100 Series Vactor from the cold. The truck, parked near Gate 2, is 70 feet above the Poe Lock floor. A 90-degree elbow connects the shoot to 260 feet of 8-inch Schedule 40 PVC pipe.

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Multiple contractors attempting to clean the manholes and underfloor drainage system of the Sault Ste. Marie (Mich.) Poe Lock in early 2013 were thwarted by ice clogging hoses and vacuum lines. The work, scheduled from Jan. 15 through March 25 when the locks are closed for maintenance, was never completed.

In late 2013, the U.S. Army Corps of Engineers put the project out to bid again. “We contracted to clean 14 48-inch manholes and 1,700 feet of 12-inch pipe,” says General Manager John Fukey of Tunnel Vision Pipeline Services in Escanaba, Mich. “That’s normally a one-day job.”

However, the 2013-2014 winter at the Soo was one of the coldest and snowiest on record. Daytime temperatures averaged minus 30 degrees F. The lock funneled Arctic air off Lake Superior, causing wind chills to reach minus 80 degrees. Almost daily storms dropped 123 inches of snow. Workers struggled for three weeks, but they were the first to beat the ice and clean the system.

Ice brigade

The 1,200- by 110- by 70-foot-deep lock has an upper (north) gate and a set of lower (south) miter gates. Gate 2 is a spare in case the operating Gate 3 is damaged. Most work occurred between the pair.

During maintenance, 10- to 23.5-foot-deep manholes drained water off the lock floor. Three 24-inch manhole covers at each end of the lock had 1-inch ventilation slots, allowing debris to enter. The suction created as boats passed through the lock had popped off two other lids.

The hulls also ground up the oak fenders on the lock and gates. “Our biggest issue was wood,” says Fukey. “The seven manholes between the lower gates were jammed full of it. Even with two of the 14 manholes impossible to reach, cleaning the remainder accounted for 95 percent of the project.”

The Corps lowered equipment and supplies into the lock, then manual labor took over. “After hauling around 20-foot sticks of 8-inch Schedule 40 PVC pipe for debris removal, we learned the hard way to bring your own skid-steer,” says Fukey. “Besides their weight, footing was tricky because everything was coated in ice.”

Water poured constantly through the gates and down the manholes. Fukey ran two 3-inch dewatering pumps continuously, but they couldn’t keep up. “We tried sandbagging around manholes, but water accumulated behind the bags, then spilled over,” he says.

Mean and nasty

Rocks up to 20 inches in diameter caused more problems. “The Wacker Neuson’s PG pump with Honda engine spit them out, but they jammed the impeller of another manufacturer’s pump,” says Fukey. “Freeing the impeller was risky because flesh froze instantly to metal surfaces.”

The pumps discharged through 200 feet of hose to clean-outs in the floor. Each night, workers drained the pumps and hoses. The next morning, they jammed steam lines down the hoses to warm them and into the pumps to free them enough to turn over. Steam came from the Corps’ plant.

Since Fukey’s crew had never worked with live steam, he hired Steve’s Plumbing of Sault Ste. Marie to act as steam safety adviser. “By spending $10,000 on steam hoses and feeding steam into our cleaning lines, we beat the ice that defeated other contractors,” says Fukey.

The warm pipes and hoses melted trenches in the snow and ice, and had to be pulled out frequently. Workers often fell on snow-covered ruts as they freed lines and moved snow, but no broken bones or concussions resulted. To avoid slipping and falling down a manhole, workers spread ice-melting crystals around the structures.

Overhead ice on gates and walls was another threat. Occasionally, the sun was warm enough to loosen chunks slightly smaller than a Volkswagen Beetle. “The Corps let steam lines blast for hours to melt ice above an area where we’d be working,” says Fukey. “They just couldn’t get all of it and some fell near us.”

First order of business

The Corps marked a route to a parking space alongside the lock for Fukey’s Vactor 2100 Series combination sewer cleaner. Any deviation from the path could damage property. He covered the truck with tarps to help keep it warm and subcontracted Ken Norris Construction of Sault Ste. Marie to deliver 170-degree water in a 3,000-gallon tanker to use in the machine.

Workers assembled 65 feet of PVC pipe on the floor, tying the joints with heavy rope to prevent separation as they hoisted the shoot up the wall to the truck. A fitting connected the pipe to the corrugated vacuum tubing, and a roll of duct tape reinforced the connection.

The crew assembled 260 feet of PVC pipe to reach the nine manholes at Gate 3 and attached the pipe to the shoot with a 90-degree PVC elbow. Then they brought down the 65 gpm/2,000 psi jetter and 300 to 400 feet of 1-inch hose.

The manholes – all below the frost line – had 30-inch-diameter chimneys for 4 feet before expanding to 48 inches. Drainpipes entered at 6 inches to 7 feet from the bottom. Dewatering the manholes had little effect, and workers vacuumed 10 times as much water as material.

Provided the decanted water was almost debris free, the Corps allowed Fukey to discharge it into the lock. The Vactor, pulling 18 inches Hg, sucked water and maybe some sand, if in solution, but it couldn’t pull rocks or wood. “We dumped four loads of water and very little debris the first two days,” says Fukey. “The Vactor is a good machine, but it wasn’t designed to do what we were asking of it.”

Then the cold caught up with the truck, breaking several lines and the hydraulic fluid cooler. Fukey substituted his 1988 Aquatech B10 combination cleaner (Hi-Vac Corp.) with 10-cubic-yard debris tank, 1,000-gallon water tank, 65 gpm/2,000 psi water pump and 2,700 cfm/15-inch Hg positive displacement vacuum system. “We made better headway the next four days, but it still wasn’t fast enough,” he says. “Even this truck struggled to move rocks and wood.”

Regroup and attack

Brutal cold and massive snowfalls canceled work the next week, allowing Fukey to make equipment changes. He hired Roger Fritz of Bosk Corp. in Escanaba to bring a Supersucker Model 5227 (Super Products) with 13-cubic-yard debris tank and 6,000 cfm/27-inch Hg positive displacement vacuum system. (Bosk had removed the water tank and pump for simplicity and weight reduction.)

“The machine pulled rocks through the pipe so fast they smashed through the elbow,” says Fukey. “We padded the back of it and used more than 100 rolls of duct tape making repairs.” Fritz dumped debris three times a day, averaging 3 to 5 cubic yards per load.

Once workers uncovered the drainpipe in a manhole, they lowered the jetter hose on a hook, positioned the nozzle in the pipe, and turned on the pump. With little debris in the lines, cleaning to within 3 inches of the bottom went quickly.

“We couldn’t stay dry,” says Fukey. “Our faces were always wet from spray, but water freezes at 32 degrees, which was 62 degrees warmer than the air temperature.” Although the crew had an insulated ice-fishing shack with portable propane heater in the lock, the work was so strenuous they seldom used it. They met their March 14 deadline and left the lock’s drainage system flowing freely.


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