Robert Erskine.

About Robert Erskine

Robert Erskine (1735–1780) was a Scottish inventor and engineer who came to the British colonial Province of New Jersey in 1771 to run the ironworks at Ringwood, New Jersey. He subsequently became sympathetic to the movement for independence. In 1776 during the American Revolutionary War he designed an underwater cheval-de-frise that was installed across the Hudson River at the north end of Manhattan to prevent passage of British ships upriver.