We are primarily interested in fixed coastal fortifications, although land forts and batteries are of interest as part of the landward defences of harbours and ports. With odd exceptions, the primary features of fixed defences changed little through history.
- Weapons to engage enemy troops and vessels. This was primarily guns, smoothbore until about 1850. Thereafter rifled guns appeared in considerable numbers. Breach loading rifled weapons also appeared about 1885 and these guns had replaced all the other models by 1900.
- Protection for these guns, including the use of bombproof or casemated positions, sometimes with armoured shields or turrets.
- Prepared fields of fire and range finding equipment to ensure that the enemy could be hit.
- Protection for the garrison, casemated and defensible barracks.
- Obstacles to impede any enemy attack. In this case of naval vessels this including torpedoes (Brennan, Whitehead), mines and boom defences. To protect from infantry attack, ditches, caponiers and prepared firing positions.
This required within the fortification, secure storage for:
- Ammunition, and if possible, a safe distribution method with underground corridors and lifts to the guns.
- Water including reservoirs and water catchments.
- Food supplies for any siege.
- Medical facilities, including adequate hospital accommodation. These were particularly important in the unhealthier posts such as Sierra Leone.
- Coal and later oil to run steam engines to power the large guns and general electrics.
Between 1840 and 1914 the development of British fortifications was profoundly influenced by development including the introduction of the following: