Solent Forts

The Solent Forts included  four sea forts that were built after the 1860 Royal Commission, which originally recommended five forts.  One other fort, Breakwater Fort, was recommended for Plymouth Harbour. The sea forts proved problematical and expensive to build because at that time they were pushing the boundaries of technology.

The introduction of armoured faces for these sea forts was also unusual for the British experience.    This method of construction was copied for the building of Fort Cunningham in Bermuda, but was not tried anywhere else in the British Empire.  Once again, Colonel Jerviois was involved in the building of the new Fort Cunningham from 1867 onwards.   The cost of construction of the sea forts appears to have been a major consideration in the restricted use of iron armour in British fortifications.  The British tended to adopt iron shields for important positions, although iron turrets were used in some locations, such as Gibraltar, for 12.5-inch guns.

The armour was of a laminated type with alternating layers.  The armoured face was some twenty five inches thick made up of layers of iron plates, wrought-iron and teak.  The image attached gives an impression of how these armoured casemates looked.

The four sea forts built in the Solent on the approaches to Portsmouth were:

Spitbank Fort which is one of the smaller sea forts and lies just outside the entrance to Portsmouth Harbour.

No Man Land Fort which lies on the Western approaches and is similar in design to Horse Sand Fort.

Horse Sand Fort which lies on the Eastern approaches and is similar in design to No Mans Land Fort.

St Helens Fort which lies further out than the other three forts, under five hundred meters from Nodes Point Battery on the Isle of Wight.  This is a smaller fort with only three guns in roof top casemates.

An excellent video, showing all four forts can be seen on YouTube at https://www.youtube.com/watch?v=rZ5_Qz5ZpzQ.

In 1883 proposal were made for the mounting of twelve 12-inch BL Mark I guns in the casemates of both No Man Land Fort and Horse Sand Fort.  These guns appeared to have been mounted in the two Forts by at least 1893.

The Yoke Mounting was fitted to the 12-inch guns used in No Mans Land and Horse Sand Forts.  The iron brackets were anchored to the ceiling and floor and used hydraulic buffers on the yoke to help absorb the recoil when fired.  The Yoke can be seen by the trunnions of the gun, secured to an ‘I’ beam in the ceiling and a bracket on the floor.

(Professional Royal Engineer Papers of 1893 and D.A. Wood 1998)