Five massive 15–inch naval guns were installed in Singapore by the British government before 1940, with three based in Changi to the east and two located in Buona Vista to the southwest.

Collectively, the three naval guns in Changi formed the Johore Battery, named after the King of Johor, Sultan Ibrahim, who gave King George V of the UK a grand royal gift of £500,000 for his Silver Jubilee in 1935, of which £400,000 of the amount was used by the British government to fund the installation of the three large naval guns in Changi.

[2] Built by the British government in 1939 for the naval defence of Singapore (in particular, to defend Singapore from an aggressive Imperial Japan, which had possessed a strong and a powerful navy by the later part of the 1930s and was expanding deeper and deeper into China), the Johore Battery is a large gun emplacement site consisting of a labyrinth of tunnels.

They were all destroyed before the official surrender of the British Army on 15 February 1942 to the conquering Imperial Japanese military[2] and the related tunnels (for the storage of the ammunition for the guns and gun-crew quarters) were sealed up and almost forgotten after the war in 1945.

[3] In 1950 the Royal Army Ordnance Corps began an exercise to remove live gun shells that were buried at Changi during the British evacuation in 1942.