A Day's Pay According to tunnel records, the following pay rates were established for the 600-700 laborers required for this project:
ON
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Image Credit: Public DomainImage Caption: Postcard of the west end St. Clair River Tunnel in Port Huron, Michigan, United States.Era_date_from: 1891
1991
Opened July 9, 1904, this lift lock is the highest of its type in the world, transferring boats between two water levels in a single 19.8 m (65 ft.) lift. Designed in place of conventional locks, which would have lengthed the time considerably to transverse a gradual drop, this lift lock was a unique solution made feasible. It operates on a balance principle. Each boat chamber is supported by a ram, 2.28 m (7.5 ft.) In diameter. These move up and down inside water-filled cylinders connected by a pipe.
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Image Credit: Courtesy Flickr/Mac Armstrong (CC BY-SA 2.0)Image Caption: Peterborough Hydraulic Canal Lift LockEra_date_from: 1904
1999