At 524 miles, the New York State Canal System is a series of waterways that connect the Hudson River with lakes Erie, Ontario and Champlain. The canal's official operating season for boat traffic runs from May through November. Cold winters in upstate New York jam navigable waterways with ice.

But the frigid off season provides the New York Canal Corp. with ample maintenance time, a critical need to keep the canal system’s 57 locks in service.

Part of that maintenance is a once-a-decade rebuild of each lock’s wagon body valves and track system. The equipment manages the inflow and outflow of water from each lock chamber. Several locks receive valve rebuilds each off season. In 2019, that rebuild included lock E-2 in Waterford, around a 20-minute drive north of Albany.

The E-2 lock's chamber is 55 ft deep, although the rise — the difference in waterlines — is 33.5 ft. The larger downstream gates weigh around 55 tons each and hold back 5 million gallons of water when full. The lock is 328 ft long and 45 ft wide. It accommodates vessels up to 300 ft long, 43.5 ft wide, with a 12 ft draft. In just five locks (E-2, along E-3, E-4, E-5 and E-6), the canal rises 170 ft in a little over 1.5 miles — the steepest lock flight rise in the world.

“It is twice the total lift of the Panama Canal,” said John Callaghan, the canal's executive deputy director.

Two seasons: Navigational and maintenance

On busy summer days, a typical lock will cycle dozens of times. These days that traffic is largely recreational, but the canal system was key to New York trade from the canal system’s opening in 1916 until the 1960s, when overland cargo transport became more widespread. Recent evidence suggests a modest uptick in commercial canal traffic, although it remains far from the volume of the canal’s heyday.

The 55-ton gates and downstream cofferdam. The canal's operating company remains active throughout the winter with maintenance activities. Managers divide the network of waterways into seven maintenance sections, each of which alternates maintenance among its locks. Preventive and refurbishment work depends on the individual condition of each lock and its components. Gate maintenance is likely in store for E-2 during the next pump-out.

According to Callaghan, the scope of work for one of these pump-outs depends on the lock's age. For example, workers sometimes pull out the massive steel gates to replace sections of quoin wood.

"As the gates open and close, you don’t want wearing parts steel-on-steel," he said. "Typically, if the oak timbers have been in place for more than a couple of pump-outs they will need to be replaced."

Workers lower a refinished wagon body valve into its shaft.

Some gates on the canal are original and their beams often need to be removed and replaced with welding or bolting repairs.

Valve rehabilitation

Each lock is outfitted with four wagon body valves, one on each side of both gates. When the upstream valves are opened, water fills the lock to the waterline of the upper level. This is done through a series of filling ports along the base of the lock chamber. After the upper valves close, the downstream valves open. This lowers the lock chamber's water level to the downstream waterline. The process is reversed to send a vessel upstream.

The wagon body valves each weigh 11,000 lb, are roughly 7 ft wide and 9 ft high and ride a vertical shaft outfitted with rails. Paired with a counterweight and chain, the valve mechanism is driven by a century-old DC motor. No additional pumps and fluid controls are used.

“The lock is never pumping water upstream," Callaghan said. "From Lake Erie to Waterford, it is just going downstream.” Work underway in the valve shaft.

Before removing the wagon body valves, cofferdams are constructed outside of each pair of gates and the remaining water is pumped out.

A buffer beam stretches across the lock chamber. Workers then erect pilings across that beam to isolate the water level on the lock's upstream side. This allows workers to dewater the lock and enter it. The lock can be dewatered in around a day, said Callaghan.

Wagon body valves are extracted from their shafts with a crane and are shipped to the canal's nearby maintenance facility in Waterford. Mike Coon, Canal Corp. section 2 superintendent, described the technology and systems as "ancient"; many of the valves and components are more than 50 years old.

Left to right: Wheels await maintenance. A worker grinds a valve before repair. A valve being repainted..

At the repair facility, machinists disassemble the valves and sandblast them to remove old paint and debris. Machinists and welders also inspect the valve construction and make repairs as required. Wheels and axles are removed for refurbishment or replacement, and new shims are installed to keep the wheels in firm contact with the shaft rails.

Left to right: A valve is fitted for new shims. Discarded valve seals. Equalizer bars wait to be connected to valves.

Valve seals are also replaced, with the old seals serving as a machining template for the new ones. A new equalizer is installed, which keeps the valve balanced as it hangs and rides the rails in the valve shaft. The wagon rails also are removed and refinished or replaced.

A view into the lock chamber as crews remove sediment. The maintenance facility also manufactures new valves when necessary as well as components for the lock gates, such as gate hinge knubs and anchor rods. A quoin wood carpentry shop is on site.

Once the valves are refurbished, they are returned to the lock where a crane lowers them into their shafts. With the cofferdams still in place, maintenance crews inspect other lock components and systems that typically are submerged. Excavators remove a decade-worth of sediment from the bottom of the chamber. Much of the sediment is deposited by turbulent water, such as spring runoff and storms. Lock filling ports typically remain unclogged due to the immense flow pressure.

Lock valve maintenance is underway on other parts of the canal, all of it part of the work required to keep a 101-year-old canal system functioning and ready for the navigational season, which this year begins May 17.