A bridge across Lake Champlain
Back in 1777, Chief Engineer Jeduthan Baldwin of the American forces on Mount Independence commenced the building of a bridge spanning Lake Champlain between the Mount and the Ticonderoga peninsula. When completed, the bridge would be supported by 22 piers — or caissons — spread equally across the quarter mile expanse of water. Each caisson was about 25 feet wide at the bottom and tapered upward. No one is exactly sure of how the construction of these caissons was made, but we have some good guesses. The image below is by Gary Zaboly. It will be one of five featured drawings by Zaboly in the upcoming book about Mount Independence, called Strong Ground, being published by the Mount Independence Coalition.
This rendition depicts how the work might have gone with ice on the lake, but we know that the ice broke up in late March of 1777, so most of the piers must have been installed using a different method — most likely assembled on shore, then floated in to place and sunk with quarried rock for ballast.
The plan was to install a road bed atop the piers, but the Americans were forced to evacuate the site before the bridge was completed. Instead they relied on a temporary floating bridge to move men and supplies across the lake, including on the fateful night of July 5th, 1777, when the retreat began. A German soldier fighting for the British was so impressed by the work, he compared it favorably to one of the Seven Wonders of the Ancient World.
In the early 1990s, I was one of many people attending a ceremony at the point on Mount Independence State Historic Site when we noticed a log from one of the caissons had bobbed up from the bottom of the lake. Some of us took off our shoes, waded into the water and helped wrestle the log onto shore.
Today that log has been restored and resides comfortably in the museum at Mount Independence State Historic Site.