One door, thick walls and a gun that turned
How a small tower full of soldiers was meant to hold a stretch of coast.
Jump to: Shapes and sizes | Floor by floor | The gun | Bricks and mortar | Moats | Chains of towers
Shapes and sizes
Although they look round, the south coast towers are elliptical, with thicker walls on the seaward side. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers The walls are thickest on the seaward side, to turn aside cannon shot. English Heritage: History of Dymchurch Martello Tower
Historic England says the south coast towers are generally about 13.6 metres (45 feet) across. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers The walls are 10 metres (33 feet) high, tapering slightly from base to roof. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers
Tower 24’s walls are 1.5 metres to 4 metres thick, thickest at the base on the seaward side. Historic England: Martello tower no 24 at Dymchurch (list entry 1014626)
English Heritage says the east coast towers were cam-shaped, like a rounded triangle. English Heritage: History of Dymchurch Martello Tower The east coast towers are bigger, about 16.7 metres (55 feet) across, giving more room on each floor. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers
Their gun platforms were quatrefoil, or four-leafed: a 24-pounder in the seaward space and smaller carronades at the sides. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers
Tower CC at Slaughden is the only quatrefoil (four-leafed) tower in plan. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers
Floor by floor
Each tower had three levels: a ground floor, a first floor and the roof. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers
The only door was on the first floor, reached by a ladder that could be pulled up, or by a drawbridge where there was a moat. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers English Heritage says the ladder could be pulled up to stop the enemy forcing their way in. English Heritage: History of Dymchurch Martello Tower
A thick brick pillar in the middle held up a brick-vaulted ceiling and a rack for 27 muskets. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers The first floor was split into three around the central pillar: one room for the officer, one for 15 to 24 men, and the rest for stores. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers
The ground floor, reached by a trapdoor and ladder, stored gunpowder, ammunition, food, fuel and water. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers
Cisterns in the basement floor were fed with rainwater by pipes from the roof. Historic England: Martello tower no 24 at Dymchurch (list entry 1014626) The water was fed from the roof and drawn up with a pump on the first floor. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers
The magazine was lit by a light box behind a pane of glass, kept apart from the gunpowder. Historic England: Martello tower no 24 at Dymchurch (list entry 1014626) The magazine wall at Dymchurch has an alcove for a candle lantern. English Heritage: History of Dymchurch Martello Tower
The south coast towers had two small side windows; the east coast towers had four. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers Above the windows are vents to draw off smoke from musket fire. Historic England: Martello tower no 24 at Dymchurch (list entry 1014626)
In the south coast towers, a single staircase leads from the first floor to the seaward side of the roof. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers The east coast towers have two staircases, to the landward side of the roof. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers
The roof is surrounded by a sloping parapet about 1.8 metres high, with four arched recesses for ammunition. Historic England: Martello tower no 24 at Dymchurch (list entry 1014626) Recesses inside the parapet stored cannonballs, all carried up the stairs by hand from the magazine. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers
The two light chimneys could be knocked down quickly in an attack, so they would not block the guns. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers
The gun
Each south coast tower had one 24-pounder long-range cannon on a turning oak carriage, so it could fire in any direction. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers
The 24-pounder fired solid iron balls 14 cm (5½ inches) across and weighing 11 kg (24 lb) at ships over a mile away. English Heritage: History of Dymchurch Martello Tower Historic England says tower 24’s gun had a range of one mile. Historic England: Martello tower no 24 at Dymchurch (list entry 1014626)
Against landing troops it could fire case shot: a tin that burst on firing into up to 84 small balls. English Heritage: History of Dymchurch Martello Tower
The gun sat on a wooden platform that could turn through 360 degrees. English Heritage: History of Dymchurch Martello Tower The platform sloped up at the back, which slowed the gun as it recoiled so it could be reloaded. English Heritage: History of Dymchurch Martello Tower
Turning the gun took between ten and fourteen men, using rope pulleys. Historic England: Martello tower no 24 at Dymchurch (list entry 1014626)
Tower 24’s gun barrel was made by Samuel Walker and Company of Rotherham. Historic England: Martello tower no 24 at Dymchurch (list entry 1014626)
English Heritage says the east coast towers carried three guns: a 24-pounder for ships and two carronades or two 5.5-inch howitzers for troops at closer range. English Heritage: History of Dymchurch Martello Tower
Bricks and mortar
Each south coast tower needed about 250,000 bricks. English Heritage: History of Dymchurch Martello Tower Many bricks came by ship from brickmakers around London and south-east England; some were made from clay dug locally. English Heritage: History of Dymchurch Martello Tower
The Wish Tower Friends say estimates vary between 250,000 and more than 500,000 bricks per tower. Wish Tower Friends: 1794 to 1808, design inspiration and construction
The south coast towers were built of yellow-grey London brick or locally made red brick. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers The east coast towers were built of red brick made at Grays in Essex. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers
Historic England estimates that over 700,000 bricks went into each east coast tower. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers
They were built with a strong hot lime mortar that set “as hard as iron”, and then rendered. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers At Dymchurch the brick is covered in render, grooved to look like blocks of Portland stone. Historic England: Martello tower no 24 at Dymchurch (list entry 1014626)
The parapets, windows and doors of the east coast towers are dressed with stone. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers
Small differences between towers came from local subcontractors building them. Historic England: Martello tower no 24 at Dymchurch (list entry 1014626)
An 1804 design drawing, possibly by Ford, shows a hollow central pier; the towers were built with a solid one. English Heritage: History of Dymchurch Martello Tower
Moats
About one in five towers had a dry moat, usually 5 metres deep and 10 metres wide. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers The dry moat was meant to trap enemy soldiers, who could be shot at by musket from the roof. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers
Some towers also had a cunette, a water-filled trench at the foot of the tower, or a sloping bank called a glacis. Historic England, Heritage Calling blog: A Brief Introduction to Martello Towers
Chains of towers
The towers were sited close together so that their fire crossed, protecting each other. English Heritage: History of Dymchurch Martello Tower
The Wish Tower Friends say the towers were arranged close together for mutual protection. Wish Tower Friends: 1794 to 1808, design inspiration and construction
The Dublin towers were built within sight of each other, to pass on warnings quickly. James Joyce Tower: The Martello Tower
Our sources give dates and totals in different ways, and some disagree by a year or count different groups of towers. We copy each figure as its source gives it, rather than converting, so every figure matches its link. Things that can change, like whether entry is free, show the date we checked them. See when sources disagree for the open questions side by side.
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