Saturday, June 12, 2021

The Canadian Lock and Emergency Swing Dam on the St. Marys River

Lock: (Satellite)
Emergency Dam: (Satellite)

Canada has this small lock that is used for tour and recreational boats. The Soo locks for commercial traffic are on the American side.

Just downstream from the railroad bridge on the Canadian side is another swing structure, which is painted red in the photo below. This is an emergency dam. To stop the flow of water in the canal, it swings over the dam, a frame holding gates is lowered into the canal and then the gates are lowered in the frame. The Chicago Sanitary and Ship Canal had a comparable dam that they called the Butterfly Dam. Since it was never used, they have removed it.
One of 23 photos posted by Joe Granger

In 1909 it was deployed.
Old Soo posted
The emergency swing dam was only put into action once and that was on June 9th, 1909. As seen in our previous post, the swing dam was put to the ultimate test on this day when three ships, the Assiniboia, the Perry G. Walker and The Crescent City were sent rushing through the canal into the St. Marys river after the Perry G Walker rammed the south gate causing the north gate to collapse.
Built in 1896 by the Dominion Bridge Company, it is the only surviving structure of its kind anywhere in the world. There were nine built like it such as in Sault, Michigan and in the Panama Canal and to this day it remains much the same as it was on that June day 112 years ago.
Original photo was taken June 9th, 1909 by Young, Lord & Rhoades with present day comparison taken October 2019 by Jo Bumbacco.
Jo Bubbacco shared

Old Soo posted nine photos with the comment:
June 9, 1909 dawned uneventful enough but a mid-afternoon accident in the Canadian Lock caused by an American ship disregarding lockage instructions brought traffic to a standstill and closed the entire area to maritime traffic for twelve days.
The accident involved three ships. The first was the Canadian Pacific passenger steamer Assiniboia downbound from Lake Superior. Granted passage, the Canadian flagged Assiniboia had entered the Canadian Lock and tied up for lowering. 
A second boat carrying iron ore, the American flagged Crescent City, was then cleared to enter the lock behind the Assiniboia. Traffic that day was heavy and the main river channel on the lower end was clogged with ships promising delays of several hours for all upbound traffic.
 It was at this time that a third ship entered the picture, an upbound American flagged ore boat, the Perry G. Walker. Its captain chose not to wait out the delay and opted for what he thought would be a quicker passage using the Canadian Lock once the Assiniboia and Crescent City had cleared . 
The Walker weaved its way through the waiting ships on the river to the Canadian side and soon received orders to tie off at a wharf and await clearance. 
The captain ignored the instructions and attempted to move closer to the lower end lock gates in an effort to seize the first position in line. As the Walker steamed ahead, remaining distance was misjudged and the captain ordered the engine room to reverse speed. The order was apparently misunderstood by the chief engineer who subsequently set speed at all ahead full. The Walker surged ahead in the rapidly diminishing length of open channel and struck the lower gates head on. The impact of the Walker’s collision crushed the lower end gates resulting in a pressure burst within the lock. 
That pressure buckled the still open gates on the upper end as thousands of tons of Lake Superior water began cascading through the lock. After the collision the Walker was forced backward by the on rushing water and had its bow turned to port. The Assiniboia was ripped free from her moorings, and while tossing back and forth off the lock’s side walls, exited the lock to strike the now turned Walker at mid-ships on her starboard side. 
The Crescent City meanwhile was futilely attempting to tie off mooring lines on the upper end but failing to do so was carried forward banging against the lock sidewalls as had the Assiniboia before her. After striking the Walker the Assiniboia, now free of the lock and in the main channel of the river, dropped anchor in an attempt to slow her own downward rush. That action caused the Assiniboia to swing to starboard. The oncoming Crescent City, now also free of the lock, had its captain execute a full speed astern that succeeded in turning the ship enough that it struck only a glancing blow to the Assiniboia’s starboard side with somehow the stern missing the Walker to port.
 Regaining control, all three ships headed for the American side for docking and damage inspection. The Crescent City, the most heavily damaged of the three, made it to a dock but sank soon after.
Damage to the Assiniboia and the Walker did not prevent a resumption of their respective trips and both were allowed to continue on their way after safety inspections were complete. The Crescent City was left behind but was eventually raised off the bottom and using compressed air in her holds managed to stay afloat long enough to reach Lake Erie to unload her cargo of iron ore and then enter a shipbuilder’s dry-dock to seek permanent repairs.
The Canadian Lock was a mess. Water continued to surge through from the higher Lake Superior and eventually carried away the gates on both ends. After several hours an emergency swing dam was successfully used to slow the current and eventually the lock was sealed off. Water was then pumped out to reveal massive damage to the gates, walls, grates, intake valves and lock timbers. Electrical wiring had been torn loose and tons of silt and debris clogged the lock and river channel. Either the Assiniboia or the Crescent City had also struck and destroyed the lower end sill leaving the lock.
All traffic was rerouted to the American side. The Canadian government immediately undertook the rebuilding of the lock. Delays were unavoidable due to the sheer number of ships requiring passage through the two remaining locks and reduced navigation space in the river due to numerous dredges doing work in the main channel below the locks. Repairs commenced immediately with crews working round the clock and twelve days later the Canadian Lock was reopened to traffic.
The Walker’s owners and her captain were held responsible for cost of repairs. The owner’s insurance company paid a settlement to the Canadian government in excess of $55,000. It is unknown whether additional damages were ever sought or collected by the other two ships involved in the collisions below the lock.
One of the lock doors can still be found today on the East end of Ojibway Park where it washed up following the disaster. [Satellite coordinates provided by a comment, but I don't see the gate.]
All photos dated June 9th, 1909. Present day taken October 2019//Jo Bumbacco.

Sourced from: 
The Sault Museum and The SSM Canal National Historic Site.

Jo Bumbacco shared

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This photo is what allowed me to understand how it works.
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Glen Hunt: A set of spare Douglas-fir timber gates were always kept submerged just below the lock to the right in a little bay there by the rapids. The water kept them preserved. The gate lifter we had at that time could retrieve them and install them when required. The gate lifter was powered by coal and steam as I remember. The gates were built and assembled on location in the huge building at the lower area of the locks by the then, fish hatchery, then slid down a ramp into the river and floated to the location to be submerged for use when needed.

Andrew Cunningham commented on Old Soo's post
The emergency coffer dam saves the day. Postcard by the Art Manufacturing Co. of Amelia, Ohio, no. 3925.

Andrew Cunningham commented on Old Soo's post
A longer view. Art Manufacturing Co. postcard, no. 3926.

Andrew Cunningham commented on Old Soo's post
After the great wreck, townsfolk come to take a look... Art Manufacturing Co. postcard, no. 3923.






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