The work of opening up the Kent coalfields created interest from German Industrialists. They decided to explore the Canterbury area, and in 1911 the Anglo-Westphalian Coal Syndicates Ltd was set up to lease land near Chislet. They sank bore holes at six sites; Rushbourne, Hoades Wood in Sturry, Herne Bay, Reculver, Chitty and Chislet Park, to prove the coal. They originally thought that this coal could be transferred by barge to the sea, by opening up the Sarre Penn stream and the Wantsum Channel, but permission to do this wasn’t granted. Sinking was then moved to land near Westbere Court which would provide transport via the road to the north side and the railway to the South. Work started there in May 1914 but the borings found the ground to be chalk which held large pockets of water. Because of this they used the “cementation “ process whereby cement was injected under high pressure into the chalk and fissures to consolidate the ground. They reached coal at 1350ft (411 metres) in 1919.
War broke out in 1914 and the company was reorganised as the North Kent Coalfield Ltd after German interests were removed. It later changed its name to Chislet Colliery Ltd. Sinking resumed in 1915 but, due to difficult conditions, progress was slow.
For five years saleable quantities of coal were being produced, but a succession of strikes in the 1920’s caused damage to the underground roadways. Because of this, and lack of repairs, some were closed up and others abandoned. The coalfaces which were idle eventually collapsed and had to be reopened.
In 1929, when the Company was in serious financial difficulties, they appointed Mr E O Forster Brown, a leading mining engineer, to reorganise the running of the Colliery, and a Mr Charles Clark to improve labour relations. Output increased and things improved and funds became available to improve the social life of the colliers.
Many Chislet miners were Welsh as Welsh colliery companies held shares in the Chislet Company and developed a close working relationship. Until 1924 the majority of the miners lived in Ramsgate. That year the Chislet Colliery Housing Society was formed to build a small colliery village of 300 houses at Chislet. This was later renamed Hersden to distinguish it from the original village of Chislet up the road.
After Nationalisation in 1947 the colliery was extensively modernised but the end of steam trains in 1968 took away what was most of its market. The colliery closed in 1969 and the 1550 men transferred to the other three Kent pits.
The colliery was demolished and a small industrial estate now occupies part of the site. Located on the marshes of the River Stour, the colliery waste tip is now a nature reserve.