The three principal islands making up the Channel Islands are Jersey, Guernsey and Alderney. The proximity of the Islands to France made them vulnerable to attack from this direction, as shown by the German Occupation in World War 2.
During the Napoleonic Wars both Jersey and Guernsey had been protected by a number of coastal defence batteries and towers. These fortifications are covered on the page for the specific island.
From 1815 onwards little was done to improve these defences, but in the 1840s concern again began to grow about the risk of attack from France. Plans were drawn up for a Harbour of Refuge in the Channel Islands which could be used to hold the Royal Navy that could then sally out to harass in intercept any potential hostile French forces. The main harbour of refuge was finally decided to be Braye Bay in Alderney (TNA MFQ 1/700 & MPHH 1/679). In Jersey, St Catherine’s Bay (TNA MPHH 1/679) was also considered and the Northern breakwater arm completed. In Jersey both St Aubin’s Bay and the bay below Fort George were considered (TNA MPHH 1.679) in 1844 but nothing was developed.
During the 1840s many of the coastal defences in Jersey and Guernsey were enhanced. During the 1850s Alderney was turned into a fortified Island. Details are given on the respective pages, ALDERNEY, JERSEY and GUERNSEY.
By 1905 most of the old sites were redundant with the following coastal defences in place:
Fort Albert – Two 6-inch BL guns
Roselle Battery – Two 12-pdr Q.F. guns
In 1905 the coastal defences in Jersey were concentrated around St Helier with:
Elizabeth Castle – Two 4.7-inch Q.F. guns on the Cavalier
South Hill Battery – Two 12-pdr Q.F. guns, later upgraded to two 6-inch Q.F.
The coastal defence batteries were concentrated in Saint Peter’s Port. By 1905 we have:
Fort Irwin – Two 6-inch Q.F. guns
Cavalier Battery, Castle Cornet – Two 12-pdr Q.F. guns
