during the
Revolutionary War In the spring of 1778, a heavy chain supported by huge log rafts was stretched across the Hudson from West Point to Constitution Island to impede the movement of British ships north of West Point. A second log boom (resembling a ladder in construction) spanned the river about downstream to absorb the impact of any ship attempting to breach the barrier. The Hudson River's changing tides, strong current, and frequently unfavorable winds created adverse sailing conditions at West Point. Compounding this, the river's narrow width and sharp "S-Curve" there forced any large ship to
tack in order to navigate it. Cannon were placed in forts and artillery batteries on both sides of the river to attack ships when they were slowed to a halt by the Patriot barrier placed there. The chain was constructed over six weeks at the
Sterling Iron Works in
Warwick,
Orange County. The multiple forge-fire site and trip hammer was rediscovered in 2008 within Sterling Forest State Park. When completed, the chain contained iron links in length, weighing . The links were carted to
New Windsor, where they were put together and floated down the river to West Point on logs late in April. Including
swivels,
clevises, and anchors, the chain weighed 65 tons. For buoyancy, logs were cut into lengths, waterproofed, and joined by fours into rafts fastened to one another with timbers. Short sections of chain (10 links, a swivel, and a clevis) were attached across each raft then joined to create a continuous boom of chains and rafts once afloat. Captain Thomas Machin, the artillery officer and engineer who had installed the chain at Fort Montgomery, directed installation across the river on April 30, 1778. Both ends were anchored to log cribs filled with rocks, the southern at a small cove on the west bank and the northern at Constitution Island. The West Point side was protected by the Chain Battery and the Constitution Island side by the Marine Battery. A system of pulleys, rollers, ropes, and mid-stream anchors were used to adjust 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. The British never attempted to run the chain, in spite of
Benedict Arnold claiming in correspondence with them that "a well-loaded ship could break the chain." Polish engineer and
Patriot volunteer
Thaddeus Kościuszko contributed to the system of fortifications at West Point. == Memorials ==