In 1885, the Fort was due to change considerably from when it became operational in 1878. The 64 Pounders would be retired from service, and a new emplacement with a Mark IV 9·2-Inch BL Gun would be constructed. This gun would give the Fort much more hitting power, and at a greater range. Another 7-Inch RML Gun with an underground magazine and store room would give added cover to the south from atop Mount Siloso. A Look Out Post would also be constructed on Mount Siloso near the new 7-Inch Emplacement. The new guns are shown as the No.3 and No.5 Guns in the plan. The No.3 Gun is the 9.2 Inch BL Gun.
