The cheval de frise is a defensive obstacle, existing in a number of forms, principally as a static anti-cavalry obstacle but also quickly movable to close breaches. The term was also applied to under
A Confederate cheval de frise at the Fort Mahone defenses during the siege of Petersburg
The knife rest, or Spanish rider – a modern wire obstacle of similar function – is sometimes also called cheval de frise.
Chevaux de frise, according to the later use of the term, could include broken glass studding the top of a wall in a nineteenth-century fort.
Outline showing the structure of a Cheval de frise for river use: Illustration A: Side view; Illustration B: Top view
The Hudson River Chains were a series of chain booms constructed across the Hudson River at West Point by Continental Army forces from 1776 to 1778 during the American Revolutionary War. These served
Cheval de frise
…version of the cheval-de-frise to prevent British warships from proceeding up the Delaware River and Hudson River, respectively. A cheval de frise of Erskine's design was placed between Fort Washington at northern Manhattan and Fort Lee in New Jersey in 1776. The following year construction began on one to the north…
"Fields of Fire" from Fort Constitution on the Hudson River during the Revolutionary War
Sketch of the Great Chain and log boom
The remnants of the earthworks of Chain Battery on Flirtation Walk
The Great Chain and mortars