The ups and downs of a Canal

Story by Kiran Hubbard

Photos by Kayla Breen and Zach Krahmer

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. 

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. 

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.