Mark 24 6-Inch BL Gun
Siloso Point Tower and searchlights

The Director Tower and Searchlight Posts at Siloso Point.

There is a lot to see of the changes which have been made to Fort Siloso and its armament over the years. You will need to look carefully at times though. Some things have vanished altogether such as two of the 7-Inch RML emplacements, the 64-Pounder and 9.2-Inch Gun emplacements . However, there are remains of the 9.2 Inch Gun’s ammunition hoists to be found in the 6-Inch BL Magazine.

There may also be some remains of the 1878 64-Pounder Emplacements to the south of the Casemates. Some clearance and excavation work would be required to establish what, if anything of the emplacement remains. Traces of the No.2 7-Inch RML Gun Emplacement can still be found at the west side of the shop and Surrender Chamber.

Unfortunately, the owners of Fort Siloso have made some alterations to the Fort. These changes are noted in the relevant sections of the website. These changes give the visitor a false sense of what should be there. It is a great pity that this has happened.

Locations of the Guns

Aerial photo of Fort Siloso 7-Inch RML Gun 6-Ich BL Gun 7-Inch RML Gun 6-Inch QF Gun Siloso Point and 12 Pounder
Yellow shaded areas link to further information.

Gun Calibres explained

The mixture of names of guns in the fort, such as; 7-Inch, 9.2-Inch, 25-Pounder, 64-Pounder, ML, RML, QF & BL, can cause some confusion and requires explanation.

In the early days of artillery, guns were classified by the weight of the solid shot (cannon balls) they fired. This identified the gun’s calibre fairly accurately as the size of a cast-iron cannon ball of a given weight did not vary very much. Cannon were themselves built in different sizes and weights, but may used the same size of shot, 6 Pounder for example. Some had longer barrels and used a greater propellant charge and became known as ‘Long 6 Pounders’. The size of the cannon was immaterial, 6 pounders fired the same weight of shot.

As the size of cannon increased, so did the weight of shot. There were 32 pounders, 64 pounders etc. Other weapons such as mortars and howitzers firing shells rather than solid shot were introduced, and muzzle sizes grew. It soon became common for these weapons to be known by their muzzle size, such as 13-Inch Mortar. There were now two methods of identifying guns and in Britain, this was the case until after the Second World War. The move to using the muzzle’s diameter may well have been influenced by the weight of shot of the larger weapons as well. A 15-Inch naval shell would weigh 1,920Lbs (872Kg), which would be a bit longwinded as the name for a gun.

ML means ‘Muzzle Loading’. The barrel of this type on weapon was smooth. The gunpowder charge was inserted into the barrel and rammed down to the breech end (rear of the gun), The cannon ball or shell was then inserted and rammed down to the charge. A vent pick was pushed down the touch-hole or vent to pierce any bagged charge. A priming charge of gunpowder was poured into the hole and the gun was ready to aim and fire by means of a slow match or fuse. Later guns used a friction cap or percussion cap instead of a priming charge.

A shell showing the driving band6 Pounder RoundRML means ‘Rifled Muzzle Loading’. These guns were still loaded as above, but they had a series of grooves cut into the barrel from the muzzle down to the breech end. The shell in early days, had several metal studs protruding slightly from the base end. These engaged in the grooves and when the gun was fired, made the shell spin in flight. This stabilised the shell in flight and improve accuracy. The studs were later replaced by copper ‘Driving Bands’ (LEFT: 6-Inch Shell) which are more efficient.

QF stands for ‘Quick Firing’. A QF gun had the shell and propellant charge in a brass case all as one unit (RIGHT: 6 Pounder QF Round). The ‘Round’ of ammunition was inserted in the breech end, the breech closed and the gun fired. This enabled a very rapid rate of fire to be achieved by the gunners.

BL stands for ‘Breech Loading’ As with QF, the gun is loaded at the breech end. The shell is inserted first, followed by a bagged propellant charge from which a tape is pulled to expose the propellant. A ‘Firing Tube’ is inserted in to the Breech block to fire the gun.

In February 1942, each 6-Inch BL Gun at Siloso had available 500 AP (Armour Piercing) shells and 50 HE (High Explosive) shells. Additional ammunition was held in reserve possibly at Mount Imbiah.