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(2) Construction of a vehicular tunnel under the canal.

(3) Modification of existing bridges across the 14-mile Beauharnois Power and Seaway Canal.

(4) Ancillary works in connection with the locks at Beauharnois.

Lachine Section (31 Miles, All in Canada):

Work done by the St. Lawrence Seaway Authority of Canada:

(1) Construction of two locks, Cote Ste. Catherine and St. Lambert.

(2) Construction of an 18-mile canal and two turning basins. (3) Alterations to four highway and/or railroad bridges in the Montreal area.

(4) Other ancillary works, including the relocation of properties, road construction, and security fencing.

Physical Characteristics, Operational
Practices, Transiting and Sailing

Data on Seaway

BASIC DIMENSIONS-LAKE ERIE TO MONTREAL SEAWAY

There are seven new locks in the St. Lawrence River, five in Canada operated by the St. Lawrence Seaway Authority of Canada, and two in the United States operated by the St. Lawrence Seaway Development Corporation. All locks are similar in size. The specifications are:

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The locks at the Welland Canal have the same controlling dimensions as those in the new Seaway-Montreal to Lake Ontario.

The controlling channel dimensions for the Seaway, Lake Erie to Montreal, are:

Depth to a minimum of 27 feet-to permit transit of vessels drawing 25 feet (fresh waterdraft).

Width of channel:

(a) When flanked by two embankments-.
(b) When flanked by one embankment_

(c) In open reaches___.

200 feet minimum

300 feet minimum

450 feet minimum

Wherein feasible, these dimensions have been increased to 600 feet.

LOCKING ARRANGEMENTS

The locks have long approach walls at both ends, varying in length ranging from 1,650 to 3,000 feet, with the top of the walls normally about 6 feet above water. All approach walls are equipped with bollards suitable for berthing and for maneuvering vessels while waiting or entering the locks.

All locks are built of concrete. the locks on top of the lock walls. equipped with electric winches which are used to assist in bringing the ship's lines to the top of the lock wall where they are secured to the bollards.

Bollards are spaced along both sides of
On the operating side, the bollards are

Ships maneuver themselves into and out of the locks, and provide and manipulate their own lines. Heaving lines are passed to the vessel as it enters the locks and the shore linesmen (employed by the Seaway agencies) loop the vessel's lines (usually four) over the bollards. When the lockmaster informs the vessel that the lines are secure, the vessel is required to keep them taut by use of power deck winches as the vessel is raised or lowered in the lock.

LOCKING A SHIP

All locks of the St. Lawrence Seaway are filled and emptied by gravity, and all except the Iroquois lock are filled and emptied through side ports near the bottom. To raise a ship in the lock, the water is allowed to flow into the chamber from the upstream pool by opening the valves at the upstream end. The water flows into the wall culverts through openings upstream from the upper gates and then pours into the lock chamber through "ports," specially designed holes in the lock walls located along each side near the bottom of the walls. The following diagram illustrates the procedure.

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The following numbers illustrate the steps to lock a ship upbound: 1. On the lower level the ship sails through the open gates into the lock. After entering, the gates are closed.

2. Water flows into the lock. As the water level rises, it lifts the ship up. 3. When the ship reaches the higher level, the upper gates are opened. 4. The ship sails out into the water at a higher level.

To lower a ship, the above steps are made in reverse.

LOCKAGE TIME

The rate of filling and emptying a lock is rapid. As an example, it takes about 7 minutes to raise or lower the water level at Eisenhower and Snell locks. Approximately 22 million gallons of water are used for each lockage.

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