Photo Essay: An inside look at winter work at the Soo Locks
Feb 06, 2018 01:35PM
● By Editor
It took several 300+ horsepower pumps 16 hours, and by Saturday morning the Poe Lock was nearly empty. A worker was kind enough to stop for a moment and pose for this photo to help illustrate the impressive size of the empty lock Photo Courtesy: U.S. Army Corps of Engineers, Detroit District
By Roxanne Werly of UpNorthLive.com
With the busy shipping season wrapped up, crews are doing critical maintenance on the Soo Locks.
The U.S. Army Corps of Engineers, Detroit District has the following maintenance work scheduled: Poe Lock Miter and Quoin Block Replacement, Poe Lock Gate 2 Embedded Anchorage Replacement, Poe Lock Gate 3 Cylinder Seal Replacement, North Poe Lock Valve Maintenance, MacArthur Lock Embedded Anchorage Replacement, MacArthur Lock Filling Valve Seal Replacement, and MacArthur Lock Bevel Gear Replacement.
“It is vitally important that we keep the infrastructure at the Soo Locks in good working order,” said Lt. Col. Dennis Sugrue, district engineer. “The district puts a high priority on keeping the locks functioning safely and reliably for the benefit of our nation.”
The U.S. Army Corps of Engineers awarded the contract for more than $2.8 million to replace MacArthur Lock embedded anchorages to Morrish-Wallace Construction Inc., of Cheboygan, Mich., (d.b.a.) Ryba Marine Construction.
More than 4,500 vessels carrying up to 80 million tons of cargo maneuver through the locks annually. Iron ore, coal, wheat and limestone are among the most frequently carried commodities.
Opened in 1969, the Poe Lock is 1,200 feet long. The MacArthur Lock was opened in 1943 and is 800 feet long.
For this shipping season the last freighter passed through on January 15, which kicked off the construction projects on both the Poe and MacArthur Locks. The locks will remain closed until March 15.
Here's a glimpse of what happens behind the scenes to get the work done:
According to the U.S. Army Corps of Engineers, to get heavy equipment to the island between the locks, after the MacArthur Lock closes, a "bridge barge" is installed above the lock and a temporary roadway is built across its decks.
The water was only 33 degrees but the divers wear special suits that pipe in heated water keeping them warm and comfortable to work for several hours. Here a dive tender assists a diver working on sealing the stop logs.
On the surface dive tenders keep track of the umbilical lines carrying air, communications and the hot water that warms the divers' suits.
Cameras on the divers' helmets allow the dive supervisor to see what the divers see.
The logs are prone to leaking on the ends where they touch the walls and along the sill at the bottom where the concrete sill is worn. Divers use oakum to fill cracks and reduce leakage. Here a tender is lowering a special basket with a fresh load of oakum to the diver below.
Crews began their efforts to clear ice well ahead of dewatering the lock. Steam pans were lowered over the gates and insulating tarps were put in place to help melt the ice.
At the lower end crews begin closing the lower guard gates.
The tug Owen M. Frederick helps nudge the gates into postion as crew members watch the mitre and stay in communication with the men operating the captstans above.
It took several 300+ horsepower pumps 16 hours, and by Saturday morning the Poe Lock was nearly empty. Here a worker illustrates the impressive size of the empty lock.
A series of manhole covers on the lock floor have to be manually lifted and wedged open to help drain water from the lock floor.
Here's a view from the lower end looking west.
Crews use a small boat to access a flooded debris pit and use airlines to break up the ice.
On the lock floor a worker uses a steam line to thaw and clear a drain.
Crews use an underwater camera to check the condition of a drain in the debris pit.
Crews use an air lift and air line to clear a drain.
A crane lowers a man lift onto the upper sill, beyond you can see the stop logs in place.
With the man lift out of his view, the crane operator relies on instructions from below.
A bobcat breaks up and moves some large chunks of ice on the lock floor.
One of the many tasks for winter lay-up is "blocking the valves" deep in the lock. Here a crew has just finished placing wooden blocks below the tainter valve to prevent it from freezing to the floor. Tainter valves in the culverts are raised or lowered to allow water to flow into or out of the lock chamber.
The culverts are a very dark and very wet place, even when the lock is empty. Here a worker is making his way out of the lock through one of the emptying ports at the lower end.
As this photo reveals, much of the lock is hidden from view during the navigation season. In the foreground is the forebay where you see the emptying ports in the wall on either side, then the sills and debris pits for the two lower sets of gates, the lock chamber beyond, and the upper sill and stop logs at the far end.