St Andrew’s Bastion (Is-Swar ta’ Sant’ Andrija) was originally built after the Great Siege with work commencing in about 1566.  The bastion is two tiered with massive limestone walls covering the Marsamxett Harbour and area around the South of Fort Manoel. To the rear of St Andrew’s Bastion was St Michael’s Bastion with a battery of coast defence guns. St Michael’s Bastion was an extension of Spencer’s Bastion.

In 1861 St Andrew’s Bastion mounted the following heavy guns: One 68-pdr, one 10-inch gun, five 8-inch guns, and two 24-pdr.  These were all smoothbore guns.  These nine guns were distributed thus:

Upper Level

One 68-pdr SB gun

Two 8-inch SB guns

Two 24-pdr SB guns

Middle Level

One 10-inch gun

Lower Level

Three 8-inch SB guns

On the 12th September 1888 authority was given to build a new gun emplacement on the Upper Level of St Andrew’s Bastion.  Work commenced on 6th September 1888 and was completed on 28th December 1889.  The estimated cost of this new emplacement was £1,824 but the actual cost was  £2,061.

The new emplacement mounted a 6-inch Breech Loading gun on a hydropneumatics (HP) mount allowing the gun to disappear.  From the plans of this new HP emplacement, we are able to see that there was an 9-inch RML gun mounted in the West corner of the Bastion, directly opposite Fort Manoel.  It is believed this was the old emplacement of the 68-pdr SB gun in 1861.