Littlehampton Fort was built between 1853 and 1854 to a total cost of £7,615. Built on sand dunes overlooking the River Arun, the works are shaped like a lunette (moon shaped) with mounting for five smooth bore guns. The battery was protected by a dry ditch, 27 feet wide that had three open caponiers to provide flanking fire. The battery was surrounded by a Carnot Wall on three sides, the gorge being covered by defensible barracks. There is a small underground magazine at both ends of the gun battery.
Returns from 1876 show the battery armed with three 68-pdr SB guns and two 32-pdr SB guns. It was never upgraded to RML or BL guns and by 1888 appears to have been disarmed. Littlehampton, in comparison with other commercial ports, was given a very low priority and by 1888 was not considered worth defending with fixed coastal defences. The Fort was primarily used as Barracks, accommodating from 20 to 70 soldiers and then dependents.
Littlehampton Fort is similar in layout, although smaller and less imposing, to Shoreham Redoubt. The original name of the position was West Bank Fort.