The Hudson River's narrow width and sharp turns at West Point created adverse sailing conditions and prompted construction of a Great Chain in 1778 as an obstacle to the movement of British ships north of this point. American soldiers positioned the chain to impede the progress of a ship should it attempt to turn into the east-west channel against frequently unfavorable winds and a strong current. Cannon were placed in forts and batteries on both sides of the river to destroy the ship as it slowed to a halt against the obstacle.
When finally completed, the 600-yard chain contained iron links two feet in length and weighing 114 pounds. Including swivels, clevises, and anchors, the chain weighed 65 tons. For buoyancy, 40-foot logs were cut into 16-foot sections, waterproofed, and joined by fours into rafts fastened with 12-foot timbers. Short sections of chain (ten links and a clevis) were stapled across each raft. Later the chain sections were united.
The Great Chain (continued)
On 30 April 1778, Captain Thomas Machin, the engineer responsible for assembling and installing the obstruction, eased the chain across the river, anchoring its northern end under the protection of Marine Battery in the cove to the right of the promontory to your front on Constitution Island. The southern end was secured in a small cove guarded by Chain Battery at the river's edge to your immediate right front. Both ends were anchored to log cribs filled with rocks, a system of pulleys, rollers, ropes, and mid-stream anchors adjusted the chain's tension to overcome the effects of river current and changing tide. Until 1783 the chain was removed each winter and reinstalled each spring to avoid destruction by ice. A log "boom" (resembling a ladder in construction) also spanned the river about 100 yards downstream to absorb the initial impact of a ship attempting to penetrate the barrier. Several links of the chain are located at Trophy Point to your left rear. A section of the boom was recovered from the river in 1855 and is now on display at Washington's Headquarters Museum in Newburg.
A map of the Hudson River and the Great Chain is shown on a bronze tablet just south of Kosciuszko's Monument on the Fort Clinton parapet to the east of this point.
The British fleet never approached West Point and the strength of the Great Chain was never tested.