Foundations and Framework

The ups and downs of a Canal

Even 200 years later, these gravity-powered elevators still shape New York’s waterways and communities.

Concrete, gravity and planks of wood might not seem like much to work with, but in the hands of the right engineers, this was a recipe for one of the greatest infrastructure feats of the 19th century. 

Scattered throughout New York are critical pieces of state history in the form of lock structures from the original Erie Canal. From those protected as monuments to others lost to the wilderness, New York’s explosion onto the global economic stage can be traced back through time to these artifacts. 

While the Erie Canal may not be the industrial powerhouse it once was, it still sees frequent use during the “open” season — between May and November, weather permitting — from recreational and commercial interests alike. 

According to Patrick Stenshorn, the education program manager for the Erie Canalway National Heritage Corridor, the Canal system reported at least 74,000 lockings, or passages of boats — one or multiple at a time — through the locks, during the season last year. Canal locks remain pivotal to the functionality of the waterway.

Canal locks essentially work as elevators, lifting or lowering vehicles through areas of elevation change along the Canal. Two gates, one on the higher ground and one below, enclose the vessel in the lock while water pumps either in or out. Gravity drives this process: Slats in the bottom of the gate open to allow water to either flow in and raise the interior water level, or flow out and lower the water level, depending on the direction the vehicle is traveling. 

A new era of engineering

The Canal was a groundbreaking development in transportation and infrastructure when it was finished in 1825. To tackle the project, engineers took inspiration from narrower English canals, adapting the mechanisms they observed overseas to the wider Erie Canal. Many of these engineers had not received formal training before working on the project. 

“It was very much a sort of ‘learning on-the-job’ process. And to me, it’s amazing that this thing worked because they really didn’t understand the hydraulics,” said Sam Clemence, a Syracuse University engineering professor. “The Canal leaked three or four inches of water every day just because they didn’t have good waterproofing techniques.” 

The frequent trial and error during the Canal’s construction turned out to be such an effective method of education that the Erie Canal project came to be known as the first practical American school of civil engineering, according to the Erie Canalway National Heritage Corridor. The first formal civil engineering university in the United States, the Rensselaer Polytechnic Institute — originally called Rensselaer School — was established in 1824, according to the American Society of Civil Engineers. Cofounders Amos Eaton and Canal commissioner Stephen Van Rensselaer opened the school in 1825 after most of the work on the Canal was completed. 

The unprecedented scale of the Canal required 83 locks, each 90 feet long. This spurred rapid advances in engineering strategies and materials, including Canvass White’s invention of a better-quality hydraulic cement than the one used in England. According to the Waterford Historical Museum and Cultural Center (WHMCC), he patented the cement in 1820, but was never paid by the state for his contributions. White’s limestone and clay mixture was waterproof, which was favorable compared with the preexisting mortar that would easily wash out when locks filled with water. 

The geography along the original Canal’s path presented multiple steep drop-offs. Original locks could only handle around 12 feet of elevation change due to poor insulation and leakage, making rises and drops significant barriers to the continuation of the Canal. One example is the 70-foot cliff face at the Niagara Escarpment; to keep the Canal moving through the city later named Lockport, Nathan Roberts had to design a double set of combined locks in a side-by-side staircase formation. Each set had five locks, named the Lockport Flight of Five and heralded as a feat of engineering genius. 

New tools, same mechanisms

The dimensions of the Canal were enlarged for the first time from 1835 to 1862 and again in 1918, creating the modern Canal system known as the Barge Canal. Today, the Erie Canal requires 35 numbered locks to accommodate 565 feet of elevation change between the Hudson River and Lake Erie. The modern locks are near replicas of their predecessors, with the only major changes being more effective materials and mechanization of their operation. 

Original Canal locks used wooden gates and bumpers to enclose boats and prevent collisions between boats and the lock’s walls. Modern designs have switched to steel gates and iron posts to keep boats secure in the inner locking chamber. Predating the discovery of rubber, the originals relied on a water seal —  using the pressure between the wet gate and the sill — to prevent leakage. Upgraded sealing techniques keep current locks more secure and allow them to reach greater heights. Since these are so much larger than the original designs, the gates and valves that control the slats are electrically operated, and pumps help facilitate the flow of water in and out of the locking chamber. 

Still, no number of innovations and improvements has taken away from gravity as the basic force driving the locking mechanism. 

Many of the locks from the original Canal are considered historical landmarks and act as cornerstones of the community around them, some even inspiring festivals and other celebrations. Others are less well-known or maintained — Stenshorn explained the state of such structures. 

“Some are kind of back to nature, they’ve been abandoned and they’re just kind of relics of the past,” Stenshorn said. “People do still hunt them out and find them, but many of them are covered in moss, trees, vegetation, home to wildlife now.” 

Various organizations have invested considerable time and effort to maintain other locks as historical destinations. The locks must be preserved to keep from falling apart, requiring research on the original designs and engineering expertise. The National Park Service’s Heritage Documentation Program helps to stabilize these structures through 3D scans and other work. 

“The Canal history community is very big and very outspoken in wanting to preserve the state’s history, the state’s legacy and the importance of the Canal in American transportation history,” Stenshorn said. “And they are tourist destinations, and those tourist destinations bring economic development to a region as well.” 

One of the largest rehabilitation projects on the Canal involves the Lockport Flight of Five. The Flight was replaced with a larger set between 1836 and 1847, then altered again between 1910 and 1914. The southern set of locks were replaced with a double set of locks labeled 34 and 35, still in use today, while the northern set was left as a spillway for excess water. 

In an effort to enhance the locks as a tourist destination and historical artifact, the Lockport Locks Heritage District Corporation (LHDC) and the New York State Canal Corporation restored three of the five locks in the northern set starting in 2013. The rehabilitation is ongoing, with Phase III — involving making the final two locks operational — still in progress. 

While the Canal Corporation operates locks 34 and 35, which facilitate the flow of traffic through the Canal, teams of volunteers from the Lockport community are in charge of the restored flight. These teams run the flight to demonstrate the locking process for visitors using a “show” boat built by the Buffalo Maritime Center. Volunteers are sourced from groups across the community, from Boy Scouts organizations to workplaces. 

The city of Lockport also recently constructed a tribute to the lock tenders who operated the flight in 1897. The 14 life-size bronze sculptures sit on the steps leading to the locks. After the completion of each step of this tribute, the descendants of those memorialized were invited back to Lockport for the dedications. Elected state officials, dignitaries, canal corporation officials and musicians all came together to be part of these ceremonies. 

“The Lockport locks have become a real focal point for the community,” said David Kinyon, chairman of the LHDC. “We’ve decided that we not only want to focus on the engineering significance of the design and operation of the Flight of Five locks. We also want to celebrate the heritage and the people who manually operated the Erie Canal locks.” 

Similar community events took place after each phase of revitalizing the Flight of Five. Other annual celebrations happen at the “opening” and “closing” of each Canal season, such as Locktoberfest near the end of September or beginning of October. This festival involves a large farmers market with local food vendors, beer and wine, music and other opportunities for community members to enjoy time together. 

Linda Roth, who serves on the Lockport Locks Heritage District Corporation Committee, contributes to various projects on the Lockport Flight. Her work with the committee has helped her to feel a deeper connection and involvement with her community. 

“The engineering aspect of the Canal is incredible to me. And how they had the foresight, in 1817 or 1820, and not having an engineering background,” Roth said. “The fact that they could figure out how to raise the boat up the 60 feet of the escarpment, to me that’s amazing. Without having the technologies that we have today, they were able to think through that.” 

Roth noticed economic and cultural shifts throughout downtown Lockport since restoration efforts surrounding the city’s history began. The demonstration of guiding a boat through the partially rehabilitated flight and other public events drive tourism income by encouraging people to shop at local businesses. 

“We’ve got more smaller local shops now,” Roth said.“I think that’s important, just to bring people down here, to have pride in the Main Street community.”

Road tripping around 300 miles from Lockport will bring lock enthusiasts to another town embracing Canal culture. Waterford, a small town just north of Troy, has been heavily influenced by the presence of its own nearby locks. Opened for use in 1915, the Waterford locks were crucial in developing the Barge Canal past the intersection of the Hudson River and the Mohawk River. With an elevation change of 169 feet in less than two miles, the Waterford Flight represented the greatest lift over the shortest distance in the country at the time it was built, according to WHMCC. 

“The flight of locks is the center of this community. We have a lot of festivals around it — we have a tugboat festival that happens at the end of the summer,” said Elliot Gnirrep, director of WHMCC. “The community comes out, we have tents, there’s food, the museum sells vintage tugboat postcards. This year, I think 100 or so kayakers went through the lock, which was kind of amazing to see them all just come out of the lock. It’s just a big multi-day celebration remembering the importance of the lock and the tugboats that work on it.” 

Today, the Waterford Flight primarily sees tourist interaction but is also used to transport especially large cargo. Pieces of decommissioned fighter jets were recently shipped through the locks to their new home in the Empire State Aerosciences Museum in East Glenville, a town of 6,000 in Schenectady County.

As the Erie Canal commemorates its 200th birthday, efforts continue to rehabilitate historical locks and research potential modifications for those still in operation. Decades after their completion, these locks may still have more to contribute to the Empire State.

Following the Canal craze

Almost a century after the construction of the Erie Canal, the Panama Canal revolutionized the lock system and global trade.

Nearly 100 years after the completion of the original Erie Canal, the United States undertook another project of even larger proportions. The Panama Canal was the result of long-standing American and British business desires for a corridor between the Pacific and Atlantic oceans. It was made possible by Panamanian independence from Colombia and the Hay-Bunau-Varilla Treaty of 1903, which granted the U.S. exclusive rights to build and operate the canal. 

When it was opened for commercial use in 1914, the Panama Canal had six locks: a three-step set in Gatun, one step in Pedro Miguel and a two-step set in Miraflores. At each step, two parallel chambers allow for the simultaneous passage of boats in either direction, for a total of 12 chambers. Every original lock is 40 feet deep, 110 feet wide and 1,000 feet long — compared to the 90-foot-long original Erie Canal locks — which was an unprecedented engineering accomplishment at the time of construction, and is still considered highly impressive today. 

Although the Panama Canal only bridges 85 feet of elevation change compared with the Erie Canal’s 565 feet, its original locks are more than 800 times larger by volume than those built in 1825 for the Erie Canal. The leaps in engineering between the construction of the two canals are also apparent in that the Panama Canal’s original locks are all still operational, with the concrete in “near-perfect condition,” according to the Panama Canal Authority

These two canal lock systems use the same fundamental principle of gravity to transport vessels. Both canals have lock walls of varying heights to accommodate different levels of elevation change and lock gates that open and close consistently to moderate water flow. But while the original wooden Erie lock gates struggled with severe leakage until they were modernized, Panama’s were watertight from the start. 

In 2016, the completion of an expansion project saw two new sets of three-step locks added to the Panama Canal, one at either end. According to the U.S. embassy in Panama, these locks’ larger dimensions — 180 feet wide, 1,000 feet long and 58 feet deep — allow for Neo-Panamax shipping vessels, new generation cargo ships, to pass through. They also use water-saving basins that recycle 60% of the water used per “locking.” 

The addition of these locks reflects another difference between the two canals. While the Erie Canal primarily serves as a tourist and recreational attraction — according to the Erie Canalway National Heritage Corridor, its peak tonnage year was back in 1880, with 4.6 million tons carried — the Panama Canal is a critical waterway for international trade and other commercial use. Although the canal era of the 19th century in the United States may be long over, these pathways still have a role to play in an increasingly connected world. 

— Kiran Hubbard

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