Hilsea Lines
Encyclopedia
The Hilsea Lines are a line of 18th- and 19th-century fortification
s built to protect the Northern approach to Portsea
, an island of the coast of England
which is part of the city of Portsmouth
and its key naval base. They are now used as a greenspace and leisure area.
. The first means of crossing the creek was by stepping stones, followed by a single track built to allow the passage of pedestrians and horse drawn carts to have access to Portsea Island.
. In 1642 the fort was captured by parliamentary forces as part of the English Civil War
. It was rebuilt in 1688 and again in 1746. During the Civil War further defences were constructed by the royalists consisting of a wooden barricade mounted on the bridge backed by a small fort equipped with 4 cannon. The cannon were withdrawn on 10 August 1642 and with the barricade held by as few as eight men the parliamentarian forces were able to cross the creek two days latter. The Parliamentarians then constructed their own defences of at the site of the bridge consisting of two mounds on which a total of 6 cannon were mounted. The Parliamentarians appear to have constructed further defences near the bridge in 1643.
side of the creek under the supervision of John Peter Desmaretz. They consisted of a 15–20 ft (4.6–6.1 m) and 6 feet (1.8 m) ditch backed by a 7–8 ft (2.1–2.4 m) rampart. Water could be allowed to flow into the ditch from sluices at either end.
. Even before their completion the Hilsea Lines had been rendered obsolete by the 1859 Royal Commission
and advances in artillery
technology. The development of rifled artillery meant that it was now possible for an enemy to occupy the high ridge of Portsdown Hill
north of Portsmouth and shell the naval base from several miles away without having to attack the Hilsea Lines. To counter the new threat a series of "Palmerston Forts"
were constructed on Portsdown Hill and the Hilsea Lines were scaled back. In particular a pair of forts that it had been planned to place behind the lines were not constructed.
As completed, the lines are largely built from clay and chalk and were 30 feet (9.1 m) high when completed. Traffic on the London Road passed through the lines via a pair of 15 feet (4.6 m), 18 feet (5.5 m) tunnels. There was also an 8 feet (2.4 m), 11 feet (3.4 m) tunnel for pedestrians. The section containing the tunnels was demolished in 1919.
Then a further tunnel through the lines was provided for the railway
. Finally, a 6 feet (1.8 m) and 8 feet (2.4 m) tunnel was built through the West centre curtain to act as a sally port
.
It was originally planned to equip the lines with smoothbore
guns; however, it appears the guns may never have been fitted. In 1886 the lines were equipped with a mix of RML 7 inch gun
s and RBL 7 inch Armstrong guns on Moncrieff mountings
fitted in newly constructed concrete emplacements. Further RBL 7 inch Armstrong guns were fitted in the original casements. The guns were removed in 1903. A small number of guns were mounted on the lines during World War II.
In the 1930s western end of the moat became known as the Hilsea lagoon and in the mid 1930s work was done on the banks and it was turned into a boating lake. In the same period the land between the boating lake and the lines was converted into part of the Hilsea bastion gardens. Most of the gardens were destroyed as the result of road widening in 1968-70. In 1986 the city bought those parts of the lines that were not already under it's control. The terraces that formed part of the gardens were demolished in 2000.
In 1938 a bridge was built across the boating lake section of the moat. It was demolished in 1999 and later replaced by the current structure.
Today the lines are accessible for most of their length, but overgrown and derelict in places. The moat is used for fishing. In May 2006 the moat experienced some flooding. Most of the lines are designated as a scheduled ancient monument
. In 2010 the lines were given a Green Flag Award
.
There is a walk around the Hilsea Lines by the Mountbatten Centre to the A27 Roundabout and Reverse
Fortification
Fortifications are military constructions and buildings designed for defence in warfare and military bases. Humans have constructed defensive works for many thousands of years, in a variety of increasingly complex designs...
s built to protect the Northern approach to Portsea
Portsea Island
Portsea Island is a small, flat and low lying island just off the south coast of England. The island is totally within, and contains a large proportion of, the city of Portsmouth. It has the third-largest population of any island in the British Isles, after the mainlands of Great Britain and...
, an island of the coast of England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
which is part of the city of Portsmouth
Portsmouth
Portsmouth is the second largest city in the ceremonial county of Hampshire on the south coast of England. Portsmouth is notable for being the United Kingdom's only island city; it is located mainly on Portsea Island...
and its key naval base. They are now used as a greenspace and leisure area.
Natural defences
The island is separated from the mainland by a narrow stretch of water called Portsbridge CreekPortsbridge Creek
Portsbridge Creek is a tidal waterway that runs between Portsea Island and the mainland from Langstone Harbour to Tipner Lake...
. The first means of crossing the creek was by stepping stones, followed by a single track built to allow the passage of pedestrians and horse drawn carts to have access to Portsea Island.
Early defences
Early defences were focused on the Portsbridge that crossed the creek. A fortification is thought to have been built at the mainland end of the bridge during the reign of King Henry VIIIHenry VIII of England
Henry VIII was King of England from 21 April 1509 until his death. He was Lord, and later King, of Ireland, as well as continuing the nominal claim by the English monarchs to the Kingdom of France...
. In 1642 the fort was captured by parliamentary forces as part of the English Civil War
English Civil War
The English Civil War was a series of armed conflicts and political machinations between Parliamentarians and Royalists...
. It was rebuilt in 1688 and again in 1746. During the Civil War further defences were constructed by the royalists consisting of a wooden barricade mounted on the bridge backed by a small fort equipped with 4 cannon. The cannon were withdrawn on 10 August 1642 and with the barricade held by as few as eight men the parliamentarian forces were able to cross the creek two days latter. The Parliamentarians then constructed their own defences of at the site of the bridge consisting of two mounds on which a total of 6 cannon were mounted. The Parliamentarians appear to have constructed further defences near the bridge in 1643.
The first lines
During 1756 and 1757 defensive lines were constructed on the Portsea IslandPortsea Island
Portsea Island is a small, flat and low lying island just off the south coast of England. The island is totally within, and contains a large proportion of, the city of Portsmouth. It has the third-largest population of any island in the British Isles, after the mainlands of Great Britain and...
side of the creek under the supervision of John Peter Desmaretz. They consisted of a 15–20 ft (4.6–6.1 m) and 6 feet (1.8 m) ditch backed by a 7–8 ft (2.1–2.4 m) rampart. Water could be allowed to flow into the ditch from sluices at either end.
The current lines
The current lines were constructed between 1858 and 1871. They included special fortified bridges for road and rail access. A model of the Hilsea Lines featured in the 1862 International Exhibition1862 International Exhibition
The International of 1862, or Great London Exposition, was a world's fair. It was held from 1 May to 1 November 1862, beside the gardens of the Royal Horticultural Society, South Kensington, London, England, on a site that now houses museums including the Natural History Museum and the Science...
. Even before their completion the Hilsea Lines had been rendered obsolete by the 1859 Royal Commission
Royal Commission on the Defence of the United Kingdom
In 1859 Lord Palmerston instigated the Royal Commission on the Defence of the United Kingdom because of serious concerns that France might attempt to invade the UK...
and advances in artillery
Artillery
Originally applied to any group of infantry primarily armed with projectile weapons, artillery has over time become limited in meaning to refer only to those engines of war that operate by projection of munitions far beyond the range of effect of personal weapons...
technology. The development of rifled artillery meant that it was now possible for an enemy to occupy the high ridge of Portsdown Hill
Portsdown Hill
Portsdown Hill is a long chalk hill in Hampshire, England, offering good views over Portsmouth, The Solent, Hayling Island and Gosport, with the Isle of Wight beyond. The hill is on the mainland, just to the north of Ports Creek, which separates the mainland from Portsea Island, on which lies the...
north of Portsmouth and shell the naval base from several miles away without having to attack the Hilsea Lines. To counter the new threat a series of "Palmerston Forts"
Palmerston Forts, Portsmouth
The Palmerston Forts that encircle Portsmouth were built in response to the 1859 Royal Commission dealing with the perceived threat of a French invasion. The forts were intended to defend the Dockyard in Portsmouth. Construction was carried out by the Royal Engineers and civilian contractors...
were constructed on Portsdown Hill and the Hilsea Lines were scaled back. In particular a pair of forts that it had been planned to place behind the lines were not constructed.
As completed, the lines are largely built from clay and chalk and were 30 feet (9.1 m) high when completed. Traffic on the London Road passed through the lines via a pair of 15 feet (4.6 m), 18 feet (5.5 m) tunnels. There was also an 8 feet (2.4 m), 11 feet (3.4 m) tunnel for pedestrians. The section containing the tunnels was demolished in 1919.
Then a further tunnel through the lines was provided for the railway
Portsmouth Direct Line
The Portsmouth Direct Line is the route of a railway service operated by South West Trains which runs between London Waterloo and Portsmouth Harbour, England...
. Finally, a 6 feet (1.8 m) and 8 feet (2.4 m) tunnel was built through the West centre curtain to act as a sally port
Sally port
The primary modern meaning for sally port is a secure, controlled entryway, as at a fortification or a prison. The entrance is usually protected in some way, such as with a fixed wall blocking the door which must be circumvented before entering, but which prevents direct enemy fire from a distance...
.
It was originally planned to equip the lines with smoothbore
Smoothbore
A smoothbore weapon is one which has a barrel without rifling. Smoothbores range from handheld firearms to powerful tank guns and large artillery mortars.-History of firearms and rifling:...
guns; however, it appears the guns may never have been fitted. In 1886 the lines were equipped with a mix of RML 7 inch gun
RML 7 inch gun
The RML 7 inch guns were various designs of medium-sized rifled muzzle-loading guns used to arm small-medium sized British warships in the late 19th century, and some were used ashore for coast defence.-Design and history:...
s and RBL 7 inch Armstrong guns on Moncrieff mountings
Disappearing gun
A disappearing gun is a type of heavy artillery for which the gun carriage enabled the gun to rotate backwards and down into a pit protected by a wall or a bunker after it was fired...
fitted in newly constructed concrete emplacements. Further RBL 7 inch Armstrong guns were fitted in the original casements. The guns were removed in 1903. A small number of guns were mounted on the lines during World War II.
Post military use
When the lines were built large amounts of land was purchased by the crown to the rear of the lines. Part of this land behind the west bastion was sold to the city of Portsmouth in 1926 which built a housing estate, a school and a recreation ground on it. During 1929 and 1930 the city purchased the east bastion, the curtain wall and the land behind them. This land was used as the site for a new road link to the mainland and Portsmouth Airport. At the same time the city also purchased the West Bastion. In 1932, the eastern lines were dynamited to make room for the airport.In the 1930s western end of the moat became known as the Hilsea lagoon and in the mid 1930s work was done on the banks and it was turned into a boating lake. In the same period the land between the boating lake and the lines was converted into part of the Hilsea bastion gardens. Most of the gardens were destroyed as the result of road widening in 1968-70. In 1986 the city bought those parts of the lines that were not already under it's control. The terraces that formed part of the gardens were demolished in 2000.
In 1938 a bridge was built across the boating lake section of the moat. It was demolished in 1999 and later replaced by the current structure.
Today the lines are accessible for most of their length, but overgrown and derelict in places. The moat is used for fishing. In May 2006 the moat experienced some flooding. Most of the lines are designated as a scheduled ancient monument
Scheduled Ancient Monument
In the United Kingdom, a scheduled monument is a 'nationally important' archaeological site or historic building, given protection against unauthorized change. The various pieces of legislation used for legally protecting heritage assets from damage and destruction are grouped under the term...
. In 2010 the lines were given a Green Flag Award
Green Flag Award
The Green Flag Award is the benchmark national standard for parks and green spaces in the United Kingdom. The scheme was set up in 1996 to recognise and reward green spaces in England and Wales that met the laid down high standards...
.
There is a walk around the Hilsea Lines by the Mountbatten Centre to the A27 Roundabout and Reverse