Guide to Canal Structures

LOCK
Locks are elevators for boats, lifting and lowering them as they travel along the waterway. It takes about 15 minutes to "lock through." There are 57 locks on New York's canal system, including 35 on the Erie Canal, 11 on the Champlain Canal, seven on the Oswego Canal, and four on the Cayuga-Seneca Canal.

POWER HOUSE
Located at almost all locks, these white buildings house equipment used to generate the electricity to power lock gates and valves.

GATE CABINET
A blue and gold gate cabinet prominently displays the number of each lock in the New York State Canal System. The cabinet holds the motors and gearing that open and close lock gates and valves.

LIFT BRIDGE
Built between 1905 and 1918, fifteen lift bridges still carry traffic over the Erie Canal in western New York. Approaching canal boats alert bridge operators with three horn blasts. The operator stops traffic on the roadway and raises the deck of the bridge 15 feet into the air to give clearance for passing boats and barges.

MOVABLE DAM
Eight movable dams between Schenectady and Fort Plain are designed to regulate water flow from the Mohawk River. While they look like bridges, only two carry roadways. The gates of the dam are lowered into the river to form navigable pools during the summer but are pulled out of the water in winter to clear the way for ice and debris-filled floodwaters.

GUARD GATE
This type of gate helps to isolate sections of the canal in case of emergency, such as a break in the canal wall, accident, or extreme high water. They are also used when a section of the canal needs to be drained for maintenance or winter freeze protection.

1800s LOCK
Many of the 83 locks built on the Erie Canal in the 1800s can still be seen today. Some lie alongside today’s locks, while others are visible from the Erie Canalway Trail. These stone-walled locks were replaced by much larger and fewer concrete structures between 1905 and 1918.

AQUEDUCT
Aqueducts carried the Erie Canal over rivers and creeks. These “water bridges” were typically constructed with stone arches supporting the towpath and wooden channels carrying the water and boats. The canal system no longer uses these original aqueducts.Visit Schoharie Aqueduct in Fort Hunter, Nine Mile Creek Aqueduct in Camillus, and Richmond Aqueduct in Montezuma to see the best surviving remnants.

DRY DOCK
Dry docks are used to repair canal boats. Once a boat enters, water is drained from the chamber so that work can be done on the bottom of the boat. The NYS Canal Corporation uses dry docks in Waterford, Lyons, and Lockport to repair and store its working vessels.

BOWSTRING TRUSS BRIDGE
Bowstring truss bridges were commonly used in the 1800s to carry roads over the canal. Cast iron arches form a bow over the deck and are held together by wrought iron tension members that stretch across the bottom like the string of an archer’s bow. These bridges are also commonly known as "Whipple Bridges," named for Squire Whipple, a New York engineer who perfected and patented the design in 1840.

LIGHTHOUSE
Concrete lighthouse towers were built at Brewerton, Frenchman’s Island, and Verona Beach during construction of the Erie Barge Canal 1915 and 1916 to guide mariners across Oneida Lake. The 84-foot high lighthouse at Verona Beach has been restored and is accessible to the public. Lighthouses are also found in Buffalo Harbor and Oswego Harbor to guide boats on Lake Erie and Lake Ontario.

CANAL OPERATOR
Not a structure, but key to making the canal system work. Lock and lift bridge operators carry on a long and proud tradition of ensuring that canal structures look and run well. They operate the locks for boaters, maintain equipment, keep records of the number and types of boats passing through the system, and ensure safe passage for thousands of boaters each year.