Fort Gibson, NY-- Part 6: Two Triangles of Fire

From HMdb.

Fort Gibson, on Ellis Island in New York Harbor, was part  of two defensive triangles which made it virtually impossible for enemy ships (especially British) to approach New York City.

Any ship approaching would first have to pass through the crossfire between Fort Wood on today's Liberty Island, Fort Gibson on the west and from Castle Williams on Governors Island to the east.

In the unlikely event a ship or ships would get through that triangle it would face an even bigger challenge, passing through the second triangle formed by Ellis Island, Governors Island and the Battery of Lower Manhattan.

Within this second triangle, the farthest a ship could be at any time from the guns of one of these harbor defenses would be 1,000 yards.

No enemy ever attempted to penetrate this extraordinary  defense system.

--Brock-Perry