Coast defence has generally been the primary responsibility of navies, and fixed defence by land forces only a last resort. The debate over the merits of these two approaches has been acrimonious. The ‘wooden walls’ of Athens defeated the Persian fleet at Salamis and the battles of Sluys in 1339, the defeat of the Spanish Armada in 1588, and the battle of Britain in 1940 were all battles to defend England's coast. The defence of coastal towns and installations has been a task for artillery for 500 years, and the characteristics of the gun have shaped the design of the fort. Geoffrey Parker has argued that such gun-forts were the foundation of the great European trading empires. Coastal defences were generally constructed to defend major cities, naval bases, shipping lanes, and vulnerable trade nodes, Gibraltar being a good example of all these. Coastal fortifications do not always face the sea. ‘Palmerston's Follies’, such as Fort Nelson above the British naval base of Portsmouth, face inland against a possible enemy landing further down the coast and attacking from the rear.
The advent of armoured warships at the end of the 19th century complicated the problems for coastal artillery, but the introduction of breech-loading guns at about the same time greatly simplified coastal defence, since the detachment no longer needed access to the muzzle. A variety of complex mountings became possible. The casemate mounted a gun on a pivot which could be traversed to fire through an embrasure. In the case of mortars, embrasures were at a high angle, permitting fire from a concealed position. The barbette mounted the gun on a pivot so that it could fire over a parapet. In the late 1860s Alexander Moncrieff developed a ‘disappearing gun’ system which was adopted in varying forms around the world. This allowed the gun to be lowered for loading, rising only briefly to fire. The USA produced disappearing carriages for 16 inch guns. By the end of the 19th century, coastal forts had become increasingly invisible, with ammunition and detachments living underground along with concealed, retractable guns. Guns can also be mounted in cupolas offering the protection of an armoured dome. Many of the most impressive German fortifications of the Atlantic wall resembled armoured warship turrets set in concrete emplacements. Coastal defence artillery often pioneered developments in artillery such as survey, range-finding, breech-loading recoil systems, and the techniques of indirect fire. By the 1950s coastal fortifications had largely disappeared, being judged too vulnerable to missile attack. The Swedes still maintain formidable coastal defences and China and North Korea have developed specialized coastal defence missiles.
Bibliography
- Mallory, K., and Ottar, A., Walls of War: Military Architecture of Two World Wars (London, 1973).
- Paloczi-Horvath, G., Coast Defence Ships and Coastal Defence since 1860 (London, 1996).
- Parker, G., The Military Revolution, Military Innovation and the Rise of the West 1500-1800 (Cambridge, 1988).
- Rogers C. J. (ed.), The Military Revolution Debate (Oxford, 1995).
- Rolf, R., and Saal, P., Fortress Europe (Shrewsbury, 1988)
— Jonathan B. A. Bailey
