Please use this identifier to cite or link to this item: https://hdl.handle.net/11681/13543
Title: Ice flushing from St. Lawrence Seaway Locks : hydraulic model investigation
Authors: Saint Lawrence Seaway Development Corporation
Oswalt, Noel R.
Keywords: Floating ice
Saint Lawrence Seaway
Flushing
Hydraulic models
Hydraulic structures
Ice
River ice
Lake ice
Locks
Waterways
Publisher: Hydraulics Laboratory (U.S.)
Engineer Research and Development Center (U.S.)
Series/Report no.: Technical report (U.S. Army Engineer Waterways Experiment Station) ; H-76-9.
Description: Technical Report
Abstract: The St. Lawrence Seaway Development Corporation secured the services of the U. S. Army Engineer Waterways Experiment Station to determine, with the aid of physical model tests, the most effective and economical method of ridding a lock chamber of floating ice. Tests were conducted in an existing 1:25-scale lock model modified to simulate the pertinent features of the St. Lawrence Seaway Lock chambers. A manifold at the upstream end of the chamber proved best for flushing ice from the chamber. Flow through the manifold was pumped from various locations in the chamber or piped through the upstream miter gate sill; both of these methods were designed to create a sufficient slope of the water surface in the chamber to flush the ice. These model tests provided the means to determine the size and configuration of the manifold and the amount of flow required for total flushing. Initially, the concept of pumping water to an upstream manifold from the lower end of the chamber was tested with limited success. Total flushing of the chamber was not accomplished with the pumped high-velocity manifold submerged, and considerable spray from the high-velocity jets would generate additional ice in actual prototype conditions with the jets at the water surface. Therefore, a high discharge with a low head to reduce velocities and increase the water-surface slope was preferred for greater flushing efficiency. Heads of 38.5 to 42.5 ft at Dwight D. Eisenhower Lock (Robinson Bay) and 46 ft at Bertrand H. Snell Lock (Grass River) are available for gravity flow water-supply systems to the manifold located beneath the upstream ship bumper. These heads proved sufficient to flush 10- by 10-ft blocks of ice 1.5 and 3.0 ft thick from the entire 860-ft-long by 80-ft-wide chamber with the proper size and placement of the manifold. Optimum flushing of the surface ice was accomplished with four 4-ft-diam pipes spaced 16 ft apart between the lock walls with their center line level with the lower pool. A total discharge of 2000 cfs was required for optimum flushing. Special consideration was given during these development tests to accommodate a 2- to 3-ft variation in water-surface elevation of the lower pool ana to minimize spray which would generate additional ice. The average total flushing time for 120 blocks of 10- by 10- by 3- ft ice was 15 min.
Rights: Approved for public release; distribution is unlimited.
URI: http://hdl.handle.net/11681/13543
Appears in Collections:Technical Report

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