Littlehampton Redoubt
Littlehampton Redoubt was built to protect the entrance to the River Arun at Littlehampton on the south coast of England. A battery was planned for the east bank of the Arun at Littlehampton in about 1587, but there is no record of it having been erected and no trace of it remains. . There was though a five gun battery at Littlehampton in the early eighteenth century. In 1756 the Seven Year War with France began and there was a concern about invasion. A battery was erected on the east bank of the river in 1760. . This consisted of a bastion set at right angles to the river bank with seven guns which covered the river mouth and seafront . The rampart of this construction still remains incorporated into the amusement park called Harbour Park. .

The 1854 fort
In the early 1850s a renewed fear of French invasion led to the planning and construction of new fort on the west bank of the river. The work was completed in September 1854 at a cost of £7,615. The new fort was in the shape of a lunette, that is a straight sided crescent. Construction was overseen by Captain Fenwick of the Royal Engineers, and was carried out by a London building firm with local labour. The fort consisted of a platform for the guns with ramparts surrounded by a nine yard (eight metre) wide ditch. The ditch incorporated a Carnot wall running along its centre. This was designed to halt attackers attempting to cross the ditch. The wall itself had loop-holes for defenders to fire through. In addition at each corner were projecting open bastions from which the garrison could fire at besiegers along the length of the wall. To the rear of the gun platform was a fortified barrack block. The fort was the first of its kind in the United Kingdom; its Carnot wall and three open bastions making it unique. A further barrack block was later built outside the fort to house additional troops. The 1861 Census shows a total complement of 70 men including a gunner, surgeon, drummer, officers, NCOs and privates. The armaments, brought by sea from Woolwich arsenal, were three 68-pounder and two 32-pounder cannons. By 1873 the fort had become unable to accommodate, or defend against, larger and more powerful guns and it was taken out of service . The last master gunner, Mr Collinson, was buried in Littlehampton cemetery in 1879. The guns were finally removed in 1897 and the fort partially dismantled.

The site today
Today (2011) the fenced off site is well presented from a viewing place on a wooden walkway laid across the sand dunes. A notice with a diagram describes what can be seen of the fort, that is the surrounding ditch, one of the bastions, part of the Carnot wall and the ramparts behind.