Col. Crossman, Royal Engineers, reported on 24th November 1881 on the defences of Singapore. One of his recommendations was:
“To secure the possession of Blakang Mati Island redoubts are proposed at Mount Serapong and Mount Imbeah (sic), the former being the most important of the two, as from it a command can be obtained over the greater proportion of the island, and over the inner anchorage; as recommended in the War Office memorandum, it should be armed with three medium guns. The redoubt at Mount Imbeah might be provided with a machine gun in addition to the fire of musketry.”
The Imbeah redoubt would be garrisoned by 50 men and that at Serapong by 100 men. The total amount of infantry to be stationed on Blakang Mati was to be 250 men spread across the island. Whilst the Serapong Redoubt was completed by 1887, there was no work carried out on Mount Imbeah. The same year, the Local Defence Committee of the Straits Settlements wrote about the organisation of defence for Singapore:
“On the Island of Blakang Mati it would be necessary to construct a field redoubt on the hill designated as “Middle Hill” (Imbiah) for the purpose of resisting or denying a landing of the enemy on the south west coast of that island”.
By September 1890, arrangements were finally made for the construction of the redoubt on Middle Hill. On completion, the redoubt was armed with two 9 Pounder ML Cannon. Lt Bramwell of the Northampton Regiment commanding the 19 gunners and 82 infantry. Within a year, the number of men at the redoubt had increased to 149. Also at the redoubt were four stretchers and eight Doolies (a corruption of the Hindi ‘Doli’, meaning a litter).
RIGHT: A Mark X 9·2 Inch BL Gun on a Mark V Mounting. The photo is probably of a Mount Serapong Gun.
In 1906, a review of armament around the Empire conducted by the Owen Committee, recommended the emplacing of a single 9·2-Inch Mk.X BL Gun on a Mk.V Mounting on Mount Imbiah. At the same time, the older Mk.IV 9·2-Inch BL Guns at Fort Connaught and the 8 Inch BL Guns on Mount Serapong were to be replaced with the Mk.X Gun. A new single Mk.X 9·2 Inch Emplacement would also be constructed on the Spur of Mount Serapong. The Mk.IV 9·2 Inch BL Guns at Fort Siloso and Fort Pasir Panjang would be decommissioned and removed.
Construction work on Mount Imbiah moved slowly. The plan shows the Infantry Redoubt modified for the protection of the Battery. To the west of the gun emplacement is a PF (Position Finding) Cell which would work in conjunction with another PF Cell and the DRF (Depression Range Finder) which would be located to the north of the gun. The PF Cells would be equipped with DPFs (Depression Position Finders).
The Imbiah Battery was finally ready for action in 1912, when the gun appeared on the List of Approved Armaments as being installed. Located within the battery area was Fire Control West, which was responsible for the Imbiah and Siloso Batteries.
A bungalow with attached cookhouse (both demolished some time ago) was constructed to the north of the battery. It housed the duty crews. Close by were latrines and ablutions. The bungalow would have probably have been divided into sections for officers, warrant officers and sergeants, and for the other ranks. Other gunners not on duty at the gun, were housed in barrack blocks at the Parade Square, which was constructed around 1904.
In 1927, General Sir Webb Gillman was appointed Master-General of the Ordnance, and was sent to report on the Defences of Singapore. The need to protect the Naval Base in Sembawang, which was under construction at the time being paramount. Several new gun emplacements with armament of up to 15 Inch was recommended. Among General Gillman’s recommendations was the retention of the 9·2 Inch Gun on Mount Imbiah, but with a higher angle mounting in order to increase the range of the gun. Fire control would be transferred to Mount Serapong. The recommendation for Imbiah was not acted upon.
In 1936/37 Fort Connaught was rebuilt and equipped with three higher angle 9·2-Inch Guns which had the range to outshoot the solitary Imbiah Gun. As a result, the Imbiah Battery was decommissioned along with the 9·2 Inch Guns on Mount Serapong and Serapong Spur. In 1937, Mount Imbiah was redesignated as a “Point d'appui”, which is a place for the rallying/assembling of troops prepared for defence and war.
Despite not being armed, Imbiah remained manned and became a Reserve Magazine serving Blakang Mati, and this was its role when Singapore fell on 15th February 1942. There are no records of Imbiah being bombed although the other batteries on the island were. Fort Siloso, Fort Connaught’s Battery Observation Post on top of Mount Serapong, the Serapong Battery and Fort Connaught were all bombed. In the last days before Singapore fell to the Japanese, the men at Imbiah will have been able to see the effect of the Siloso guns on oil installations on Pulau Bukom in an effort to prevent the valuable oil falling into Japanese hands.
During the Japanese occupation, it is likely that the Japanese would have occupied the bungalow, and the battery area used as an observation post and storage depot.
Following the return of the British in 1945, Mount Imbiah was re-occupied and used as a storage facility. When the British handed Blakang Mati to the Singapore Armed Forces in 1968, Imbiah seems to have been finally abandoned. Despite all the development works on Blakang Mati which was renamed Sentosa, to turn it into an island of recreation, the remains of the Imbiah battery have survived. It is the only intact 9·2-Inch Gun Battery in Singapore. Present plans are to preserve the site.
It is likely that some remains of Imbiah’s early military life as an infantry redoubt lie hidden in the thick secondary jungle surrounding the site.