Shoreham Fort was built just after Littlehampton Fort which was completed in 1854, and bears some similarities. Shoreham Fort was built by June 1857 and cost some £11,685.10, slightly over the approved budget. Shoreham Fort had six gun emplacements, the flank positions having the ability to fire all round. There was a magazine at the end of each gun line, which also acted as a traverse. The front of the Battery was protected by a bank, Carnot Wall and dry ditch. There were three caponiers providing flanking fire along the dry ditch. The rear or gorge, was protected by a loopholed wall and defensible barracks.
The Fort, or Battery, was initially armed with six 68-pdr SB guns. By 1886 the guns had been upgraded to three 64-pdr RML guns and two 80-pdr RML guns of 5 tons. One of the gun emplacements was left empty. The 80-pdr RML was originally a 68-pdr with a rifled wrought iron liner. Introduced in 1872 these replaced some of the old smooth bore 68-pdrs. These 80-pdr converted guns were classified at this time as Muzzle Loading Rifled (MLR).
Reference: TNA WO 78/5325 dated 1886