Chain Rock Battery was established in about 1695 as North Fort when a boom was built across the channel leading to the anchorage at St John’s. The French built a six gun battery at Chainr Rock Point in 1713. By 1796 the British had established a new battery at Chain Rock with two 18-pdr guns.
On the 4th June 1846 Chain Rock Battery was reported to mount three 32-pdr guns. The situation was unchanged by 1860 when it was noted that one of the 32-pdr was on a traversing platform while the other two were on ground platforms.
In 1860 is agreed that Chain Rock Battery should retain two of the 32-pdrs, while the third traversing emplacement should mount am 8-inch gun. The earthen emplacements were to be replaced by stone, and stone tiles were to be used to mount the two 32-pdrs on garrison carriages. It would appear that this 8-inch gun was never mounted, but the old 32-pdr was replaced by a single 68-pdr SB on traversing platform.
In 1878 there was discussion of two 7-inch RML being mounted at Chain Rock Battery, or possibly Frederick’s Battery but this was not followed through. These DEL emplacements have been lost.
In April 1881 the Royal Commission looking at the defence of coaling station recommended that Chain Rock Battery mount two 10-inch RML guns. In addition two 64-pdr RML guns were to be mounted to cover the minefield across the harbour entrance. The cost of this work was some £23,720 but it was never followed through.
In 1887 a further attempt was made to upgrade Chain Rock Battery to a single 7-inch RML, the recommendation being made to the Colonial Defence Committee. Once again this proposal was never accepted.
During the Second World War, three defence electric light emplacements were built at Chain Rock Battery to cover the channel and boom.
In 1941 two 75mm guns were mounted here in concrete emplacement, these had been moved from Fort Amherst. The site was used for the boom defence (anti-submarine nets) of the harbour and images from that time show lots of buildings in the area. These World War 2 fortifications were largely built over the old sea battery.