Pre-war, only the Sphinx Battery on Pulau Tekong was armed with the Mark 24 6 Inch BL Gun. These were on a Mark V Mounting and had Mark 5 Shields.
Following the end of WWII, Fort Siloso was the only Coast Battery to be re-armed. Initially, two Mark VII 6 Inch BL Guns were recovered from elsewhere in Singapore and mounted at Fort Siloso in 1946. However, these duns had been made in 1the 1890s, and were deemed as being inadequate for the fort. To remedy this situation, two Mark 24 guns were brought from Haifa in Israel to replace them. These guns had a Mark 5 Mounting and Shield. Because of this, the emplacements had to be modified to accommodate them. These works were not major.
Differences to Mark VII Guns
The Mark 24 could elevate to 45°, giving a maximum range of 24,500 yards (22,403 m), much greater than the 14,100 yards (12,893 m) of the Mark VII. The Mark 5 Shield was larger and gave greater protection to the gunners than previous shields. The Mark 24 was able to receive electrical control signals from the Battery Observation Post, thus improving the efficiency of the gun.
The mark 24 used the same ammunition as the Mark VII. The rate of fire was the same with a similar gun detachment.
Radar was installed at Fort Siloso in 1950 to range and direct the guns. This radar was later moved to the top of Mount Serapong.
The guns could be trained and fired from the Battery Observation Post. A system called Magslip was used. This system took signals generated from range and position finders and transmitted them electrically to each gun. Receivers at the guns then elevated and traversed the guns without the need for gun crew intervention. Each gun would get slightly different information to take account of the spacing between the guns and differences in range for each gun.