6 Inch BL Disappearing Guns
A replicated 6" Disappearing Gun (No. 1)
By 1890, Lei Yue Mun Redoubt was armed with two 6 inch breech loading (BL) Mark IV guns installed on disappearing carriages. They fired a 100 pound (45 kg) projectile and had an effective range of up to 8,200 metres. Until the time for action came, the gun was concealed in the emplacement beneath its armoured shield; before firing, the power of the hydropneumatic mounting lifted it through the opening where it remained briefly in this position and was fired. Driven by the force of its recoil, the gun disappeared again into its emplacement. Around 1970, a 6 inch gun barrel was found in the ditch of the Redoubt; it was identified as one of the disappearing guns. In 1982, part of the carriage was found in the ditch. Both were sent to England and are now displayed at the Royal Artillery Museum, Woolwich. This reconstruction displayed in the Hong Kong Museum of Coastal Defence shows this gun in its firing position.