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South Bound Brook in Somerset County, New Jersey — The American Northeast (Mid-Atlantic)
 

Locks on the D&R Canal

Delaware & Raritan Canal State Park

 
 
Locks on the D&R Canal Marker Photo, Click for full size
By Bill Coughlin, May 17, 2008
1. Locks on the D&R Canal Marker
Inscription. A natural waterway follows the contours of the land over which it flows, the depth of water varies, depending on the quantity and velocity of flow. To maintain the constant depth of water required for transportation, a canal is engineered as a series of flat levels or reservoirs of water connected by locks. Crucial elements in a canal system, lift locks hold back the water in the levels, accommodate for the natural elevation changes of the land, and allow boats to travel up and down between levels.

How a Lift Lock Operates:
1.
A boat heading downstream enters the lock.

2. The lock gates are closed.

3. Wickets in the downstream gates are opened, water flows out, and the boat is lowered.

4. When water levels are equal, the downstream gates are opened, and the boat continues.

For a boat heading upstream, the procedure is reversed. Bypass channels were constructed around lift locks to allow canal water to continue downstream when locks were in use.

Locks
Outer Locks
are of the same design, but do not function as true lift locks. These locks permit the passage of boats between a canal and a river or other body of water and accommodate for changes in water level or tide. The outlet locks on the D&R Canal are at Bordentown (Lock #1), New Brunswick (#14) and Lambertville.

Guard
Marker in D&R Canal State Park	 Photo, Click for full size
By Bill Coughlin, May 17, 2008
2. Marker in D&R Canal State Park
Locks
are used in infrequently traveled areas and are similar to lift locks, but have only one pair of miter gates. The two structures in combination regulate the amount of water downstream and protect the canal from floods while allowing for the occasional passage of boats. The guard locks on the D&R Canal are at Bulls Island and Prallsville.

Water enters the Feeder Canal at Bulls Island at an elevation of about 67 feet above sea level. As it passes through the Lambertville lock it drops to about 55.7 feet, and remains at this level all the way to the Main Canal at Trenton. From this “summit” the Main Canal descended through seven locks to near sea level at Bordentown and in the other direction through seven more locks to near sea level at New Brunswick. The T-shaped section of canal defined by Lambertville Lock, Lock 7 in Trenton, and Lock 8 in Kingston served as a kind of reservoir for the Main Canal.

Gates
Locks used two kinds of gates: vertically hinged pairs of gates called miter gates, and single gates, hinged at the bottom, referred to as drop gates.Constructed to form a V-shape when closed, miter gates open upstream, and are kept closed by the pressure of the water. Miter gates are operated by pushing against long, heavy balance beams projecting from their hinged edges that counterbalance the weight of the gate. Drop
Lock on the D&R Canal Photo, Click for full size
By Bill Coughlin, May 17, 2008
3. Lock on the D&R Canal
Marker can be seen in this photo on the far side of the canal.
gates are located at the upstream end of a lock. They open by dropping against the water flow to the floor of the canal, and are usually operated by a chain and wheel (windlass) system.

Sidebar: Delaware & Raritan Canal Lock History

1831-34:
Canal was constructed with 15 lift locks (one on the Feeder and 15 on the Main Canal) and 2 guard locks. Main Canal locks were 24 feet wide and 110 feet long, much larger than locks on other canals. Original lock gates were miter gates with balance beams.
1847-48: Original masonry lock at Bordentown (#1) sank into its soft substrate and a replacement lock of stone-filled wooden crib construction was built a few feet to the west of the first one.
1848: Outlet lock was constructed at Lambertville for a cable ferry across the Delaware River. It was in operation until 1912-13.
1849: Head (upstream) gates of all locks were converted to drop gates. Today the gates are gone, replaced c.1944 by valve-operated concrete control gate structures at the head of each lock.
1853: Main Canal locks lengthened to 220 feet. Lock #5 in Trenton was eliminated and Lock #4 deepened to compensate.
1866: Second lock added in New Brunswick, making Lock #14 a double outlet lock.
1932: Canal ceased operation
1936: Trenton section of canal (Locks #3-7) filled in.
1974:
South Bound Brook on the D&R Canal Photo, Click for full size
By Bill Coughlin, May 17, 2008
4. South Bound Brook on the D&R Canal
The different water levels can be seen in this photo of the D&R Canal lock.
Delaware & Raritan Canal State Park created.
1980: More than a mile of canal at the New Brunswick end, including Deep Lock (#13), was destroyed for NJ Highway 18.
1998: Last mile of the canal and Lock #14 restored and incorporated into Boyd Park, a City of New Brunswick facility.
 
Erected by NJ Dept. of Environmental Protection.
 
Location. 40° 33.539′ N, 74° 31.847′ W. Marker is in South Bound Brook, New Jersey, in Somerset County. Marker is on Canal Road, on the right when traveling west. Click for map. Marker is in Delaware and Raritan Canal State Park, on the north side of the canal. Marker is in this post office area: South Bound Brook NJ 08880, United States of America.
 
Other nearby markers. At least 8 other markers are within walking distance of this marker. Delaware & Raritan Canal State Park (within shouting distance of this marker); Battle of Bound Brook (about 800 feet away, measured in a direct line); Queen’s Bridge (about 800 feet away); Van Horn Plaza (approx. 0.2 miles away); The Frelinghuysen Tavern (approx. 0.2 miles away); a different marker also named Battle of Bound Brook (approx. 0.2 miles away); Old Stone Bridge (approx. 0.2 miles away); Bound Brook Library World War I Memorial (approx. 0.3 miles away). Click for a list of all markers in South Bound Brook.
 
More about this marker.
D&R Canalwalk Photo, Click for full size
By Bill Coughlin, May 17, 2008
5. D&R Canalwalk
The walkway seen at the right of the photo was once traveled by mules pulling canalboats through the Delaware & Raritan Canal. Today is serves as a trail for walking, biking or horseback riding.
A map of D&R Canal Locks appears on the top of the marker. Below this is a profile of the Main Canal. It has a caption of “The number of locks necessary depends on the steepness of the terrain. The staircase is a good analogy for the lift lock canal – the risers represent the locks and the treads the levels of canal between locks.” The bottom left of the marker contains a four picture diagram showing “How a Lift Operates.”
 
Related markers. Click here for a list of markers that are related to this marker. Markers related to the Delaware and Raritan Canal.
 
Also see . . .  Delaware & Raritan Canal History. Delaware and Raritan Canal State Park website. (Submitted on January 27, 2009, by Bill Coughlin of North Arlington, New Jersey.) 
 
Categories. Waterways & Vessels
 
 
Credits. This page originally submitted on , by Bill Coughlin of North Arlington, New Jersey. This page has been viewed 1,718 times since then and 62 times this year. Photos:   1, 2, 3, 4, 5. submitted on , by Bill Coughlin of North Arlington, New Jersey. This page was last revised on June 16, 2016.
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