Martello towers, sometimes known simply as Martellos, are small defensive forts that were built across the British Empire during the 19th century, from the time of the French Revolutionary Wars onwards. Most were coastal forts.
They stand up to high (with two floors) and typically had a garrison of one officer and 15–25 men. Their round structure and thick walls of solid masonry made them resistant to cannon fire, while their height made them an ideal platform for a single heavy artillery piece, mounted on the flat roof and able to traverse, and hence fire, over a complete 360° circle. A few towers had moats or other batteries and works attached for extra defence.
The Martello towers were used during the first half of the 19th century, but became obsolete with the introduction of powerful rifled artillery. Many have survived to the present day, often preserved as historic monuments.
Origins
Martello towers were inspired by a round fortress, part of a larger Genoese defence system, at Mortella (Myrtle) Point in Corsica. The designer was Giovan Giacomo Paleari Fratino (el Fratin), and the tower was completed in 1565.
Since the 15th century, the Corsicans had built similar towers at strategic points around the island to protect coastal villages and shipping from North African pirates. The towers stood one or two storeys high and measured in diameter, with a single doorway five metres off the ground that one could access only via a ladder that the occupants could remove.
Local villagers paid for the towers and watchmen, known as torregiani, who would signal the approach of unexpected ships by lighting a beacon fire on the tower's roof. The fire would alert the local defence forces to the threat. Although the pirate threat subsequently dwindled, the Genoese built a newer generation of circular towers (the Genoese towers), that warded off later foreign raids.
On 7 February 1794 as part of the siege of Saint-Florent, two British warships, (74 guns) and (32 guns), unsuccessfully attacked the tower at Mortella Point; the tower eventually fell to land-based forces under Sir John Moore after two days of heavy fighting. What helped the British was that the tower's two 18-pounder guns fired seaward, while only the one 6-pounder could fire landward.
Vice-Admiral Lord Hood reported:
Late in the previous year, the tower's French defenders had abandoned it after (32 guns) had fired two broadsides at it. The British removed the guns to arm a small vessel; consequently, the French were easily able to dislodge the garrison of Corsican patriots that had replaced them. Still, the British were impressed by the effectiveness of the tower when properly supplied and defended, and copied the design. But they got the name wrong, misspelling "Mortella" as "Martello" (which means "hammer" in Italian). When the British withdrew from Corsica in 1803, with great difficulty they blew up the tower, leaving it in an unusable state.
Design and construction
The towers were about high with walls about thick. In some towers the rooms were not built in the centre, but more to the landside, leaving the walls thicker on seaside. These were cases where an attack with a cannon from the landside was thought very unlikely. Entry was by ladder to a door about from the base above which was a machicolated (slotted) platform which allowed for downward fire on attackers. The flat roof or terreplein had a high parapet and a raised platform in the centre with a pivot (sometimes a converted cannon) for a cannon that would traverse a 360° arc. (Some towers were designed to carry more than one gun, with each having a more limited arc of fire.) The walls had narrow slits for defensive musket fire.
The interior of a classic British Martello tower consisted of two storeys (sometimes with an additional basement). The ground floor served as the magazine and storerooms, where ammunition, water, stores and provisions were kept. The garrison of 24 men and one officer lived in a casemate on the first floor, which was divided into several rooms and had fireplaces built into the walls for cooking and heating. The officer and men lived in separate rooms of almost equal size. A well or cistern within the fort supplied the garrison with water. An internal drainage system linked to the roof enabled rainwater to refill the cistern.