The Great Chain

In 1778, the Hudson River’s narrow width and sharp turns at West Point led Americans to construct the Great Chain to obstruct British ships moving north of that point. Soldiers positioned it where adverse winds and a strong current would hinder a ship turning into the east-west channel, while cannon in forts and batteries on both sides of the river were placed to destroy any vessel slowed against the barrier. When completed, the 600-yard chain had iron links two feet long weighing 114 pounds each, and with swivels, clevises, and anchors it weighed 65 tons. For buoyancy, 40-foot logs were cut into 16-foot sections, waterproofed, joined by fours into rafts, and fastened with 12-foot timbers, with short chain sections stapled across each raft before the sections were united. On 30 April 1778, Captain Thomas Machin, the engineer in charge of assembling and installing the obstruction, stretched the chain across the river, anchoring its northern end under Marine Battery on Constitution Island and its southern end in a small cove guarded by Chain Battery. Log cribs filled with rocks anchored both ends, and pulleys, rollers, ropes, and mid-stream anchors adjusted the chain’s tension against current and tide. From then until 1783, the chain was removed each winter and reinstalled each spring to prevent ice damage, and a log boom about 100 yards downstream was added to absorb the first impact of a ship trying to break through. The British fleet never approached West Point, and the chain’s strength was never tested.

West Point, New York · United States