Fredericks Battery

Frederick's Battery is part of the dockyard sea defence wall, built between 1843 and 1848 under the direction of Captain H. James, Royal Engineers. It was dismantled and re-erected in its current position in 1867. The wall is constructed of coursed squared stone laid randomly, with ashlar dressings, and measures approximately 50 meters in length, featuring end towers. The northern tower has two stages, while the southern tower has three stages. Both towers are battered and include round-arched openings, some of which are blocked, along with vertical and looped cruciform slits.

The wall has a walkway backed by a parapet wall, supported by seven vaulted casemates—six with segmental arches and one with a round arch. Each casemate's rear wall has a blocked rectangular opening, likely a coal chute hole, as the casemates were used for coal storage at one time. The central casemate has a large entranceway. A projecting section of walling at the right end features slits above four round-arched entrances; the two central entrances are blocked, while the outer two have ashlar tympana carved with the date 1886 and a cipher.

Originally, the battery was located just west of the current No. 15 dock. When it was re-erected, it extended to the Round Tower, but the northern end was demolished in 1912 to accommodate a rail link.