The only deep water harbour between the Thames and the Humber lies at Harwich, where the rivers Stour and Orwell flow into the sea. The town had strategic importance because if it fell into the hands of an invader the harbour could be used to land an army that would be within a short march of London.
This was the concern of King Henry VIII'when he visited Harwich in 1543. Under his coastal defence programme of Device Forts, 3 blockhouses were built to protect Harwich from seabourne attack.
The medieval walls around the town were reinforced by the construction of earthworks in front of them. In addition, two bulwarks were built on Landguard Point on the opposite side of the harbour entrance. These were designed to link their fields of fire with the line of three blockhouses on the Harwich side.
At the southern end of these three was a blockhouse at Beacon Hill, the Bulwark upon the Hill, opposite Landguard Point and at the northern end was a blockhouse forming part of the old medieval town walls, the Blockhouse of the Tower. The Middle Bulwark stood half way between the two.
These blockhouses, which were probably earthwork redoubts'mounting 4 or 5 guns, were abandoned by 1553. They were garrisoned again briefly during the Spanish Armada crisis of 1588, but afterwards they were left to decay. The Bulwark upon the Hill and the Middle Bulwark both succumbed to coastal erosion and were lost to the sea within a century.
During the Anglo-Dutch wars of the 17th century, Harwich grew in importance and a shipyard was established there. In early 1667, amid fears of a Dutch attack, Sir Bernard de Gomme'was sent to survey the fortifications and make emergency improvements.
He proposed alterations to the 16th century bastioned'earthworks to form a more regular trace. De Gomme's trace had two full bastions on the landward front (facing south) and two demi-bastions'to the north of either bastion.
The earthworks were fronted by a flooded ditch'on the landward side, where an attack would have to approach the town. In the end the Dutch did try to attack Harwich but they retreated after a failed assault on Landguard Fort, which guarded the harbour entrance.
This success of Landguard Fort in protecting Harwich harbour resulted in the neglect of the town's defences. In 1717 the fort was rebuilt, but planned works at Harwich were not carried out. In the mid-18th century there were huge works to enlarge Landguard Fort but again nothing was done at Harwich.
It was not until the Napoleonic Wars that the Harwich side of the harbour was fortified again. By this stage the earthworks around the town had eroded and were of no use. The new fortifications followed a similar scheme to the Henrican works constructed 300 years earlier. There were two 5-gun batteries, Angel Gate Battery in the town and Beacon Hill Battery to the south. On the west side, covering the harbour itself, was the 3-gun Bathside Battery.
The main work however was The Redoubt, a circular fort situated on the high ground half way between the town and Beacon Hill. It was a circular fort armed with ten 24-pounders and was capable of accommodating a garrison of 300 men.
The redoubt consists of a single circular wall with vaulted barrack buildings facing the central circular courtyard. On top of the buildings lies the main gun platform, from which the open sea, Landguard Point, Harwich town, the harbour and Beacon Hill can all be surveyed. The redoubt is sunk into the hill so that, although it is in an elevated position, its walls are hidden by the deep dry ditch that runs around the outside. There was a sally port to allow the garrison to enter the ditch.
The buildings inside the redoubt were vaulted so as to be bomb-proof so that it could withstand being shelled. The bastioned system was not used because by the Napoleonic Wars the increased range of artillery had made flanking fire less critical.
The redoubt's ten 24-pounder guns had an effective range of over a mile and covered the harbour entrance, the landward approach to Harwich and the harbour itself. Ammunition was lifted to the guns from the magazines'below using 5 hoists.
The purpose of the redoubt was to provide a strong point in the Harwich defences and a command centre for local forces in the event of a French landing. Its strategic location meant that it could be used to coordinate the other fortifications around the harbour, including the Martello Towers at Shotley and Felixstowe, and Landguard Fort.
Angel Gate Battery and the Beacon Hill Battery were both roughly triangular works, each mounting five 24-pounder guns on traversing carriages. The image on the right shows a 12-pounder, a similar but slightly smaller gun, mounted on a traversing carriage.
A traversing carriage had the gun mounted on wheels that ran along rails. This allowed the gun to be traversed (turned) very quickly to bear on a moving ship. The recoil from firing forced the gun backwards up the sloping rails for reloading. It could then be pushed back down easily for firing again.
Bathside Battery, a semi-circular work armed with three 24-pounders, was on the west, facing over the harbour. This seems a strange location, since any ship in the harbour would have already passed the other fortifications and Landguard Fort.
It seems that Bathside Battery was built as a precaution against a surprise attack from ships that had somehow slipped past the other batteries and entered the harbour. In addition, it gave the garrison control over any ship already in the harbour.
The harbour was also covered from the west by two Martello Towers at Shotley, where the rivers Stour and Orwell meet. These towers could fire on any ship coming through the harbour entrance and controlled the traffic entering and leaving both rivers.
To protect Harwich from a landward attack, there was an army camp in a sheltered location behind Beacon Hill. This camp had previously been located on Landguard Point, but was moved to a less exposed position in 1795. The forces in this camp were protected against bombardment from the sea by Beacon Hill, but could deploy against a landing relatively quickly.
After the Napoleonic Wars the camp was removed and the garrison was kept to a minimum. Bathside Battery was abandoned in 1818 and Beacon Hill Battery was washed away by the sea in 1822, but Angel Gate Battery and the Redoubt were maintained.
In the early 1860s Angel Gate Battery and the Redoubt were rearmed with 68-pounders to keep up with modern artillery. Just a few years later in 1872, the redoubt was rearmed again with three 12-ton RML guns.
The old earthwork defences of Harwich were built over in the 19th century and all that survives today is a slight mound, the remains of Queen's Mount, on which stands a restored 17th century dockyard crane. The original Angel Gate Battery has been built over.
The Napoleonic Beacon Hill Battery was washed out to sea, but a new battery was built in the late 19th century and upgraded in both World Wars. Today it is overgrown and fenced off.
Bathside Battery was built over but was recently excevated and its form is outlined in bricks next to the A120. The redoubt was used during both World Wars but has now been restored by local volunteers and is open to the public. It houses a variety of exhibitions on local history and the restoration work. It is one of three redoubts constructed along with the Martello Towers, the others being the Eastbourne Redoubt and the Dymchurch Redoubt, both on the south coast.
Harwich is easily accessible by train and the remaining fortifications are within an easy walk of the station. The town is linked to Felixstowe and Shotley by a ferry, which lands next to Landguard Fort. Click here for ferry website