Stack Rock Fort stands on a rocky outcrop that was considered as suitable for a coastal defence battery from the 16th Century. It sits immediately astride of the harbour entrance giving in a clear angle of fire for any vessels entering the anchorage. The first gun tower was constructed here between 1850-51. This was the first in three stages of development.
Listing Type : Coastal Fort
Location : Wales
Stack Rock Gun Tower with smoothbore guns (1850 to 1862)
Stack Rock Gun Tower was built at the same time a West Blockhouse Battery, Dale Fort, Thorne Island Fort and the two gun towers protecting Pembroke Dockyard. Similar to the gun towers built at Pembroke Dockyard, Stack Rock Tower mounted three 32-pdr SB muzzle loading guns. The remains of this original gun tower are still largely retained within the later Stack Rock Fort.
Stack Rock Fort with RML guns (1871 to 1872)
Stack Rock Fort was one of the fortifications recommended by the Royal Commission in 1858. This new Stack Rock Fort was expanded to mount 16 x 10-inch and 7 x 9-inch RML guns. The old fort was absorbed into the new structure, much like a central keep. The guns were mounted in casemates with iron shields, 19 casemates on each of the two floors.
Defence for the submarine minefield (1886 to 1914)
No sooner had Stack Rock Fort been completed than Rifled Muzzle Loading guns it mounted became obsolete. The original casemates did not allow for the new breech loading guns to be mounted in them, thus rendering the works of little use for coastal defence. However a new role was found for it as defence location for the minefield covering the entrance to the harbour, working in conjunction with Chapel Bay Quick Fire Battery and searchlights and machine guns at South Hook Fort. Four Maxim Machine Gun positions and a directing station were built on the roof of the fort. The main Submarine Mining Depot was located at Pannar Point, close to Pembroke Dockyard.