AThe report by Jervois resulted in a 9-ins RML with iron shield being installed at Buena Vista, and this is shown on maps. In 1896 construction started on a new battery for two 12-pdrs QF guns . The 12-pdrs Q.F. Guns at Buena Vista were primarily intended to deal with:
(a) Torpedo Boats attacking from the Europa direction or from the direction of Algeciras
(b) Support batteries protecting the South Entrance to the Moles.
(c) To supported attempted landings in the area.
Before January 1902 guns Number 142 and 143 were in the Work. These two guns were sent to the Galleries (Upper Union Gallery) and they were replaced by Numbers 136 and 138. In 1901 the ammunition store was increased from 400 to 500 round. In February 1907 Guns Number 136 and 138 were moved to the Galleries, while 1498 and 1502 replaced them. In 1904 underground crew shelters were added. During WW21 AA elements were located here.