The Indented Lines were built in 1669 by Sir Bernard De Gomme. Originally called Gunners Battery, Dial Line and Long Line but changed to the Indented Lines after 1838. They were linked to the Sheerness Lines from 1827, and it was all known as Sheerness lines. They stretched from Ness Point, where Garrison Point Fort stands, down to the moat outside where Tesco now stands and all around the current steel mill. It would have had a brick revetment wall along the length of it with gun emplacements within. It enclosed the dockyard and Blue Town. Today most of the fortifications from Bridge Road and around the steel mill have been demolished, but there is a lot remaining from Garrison Point Fort along to the moat by Tesco. The fortifications range from Napoleonic all the way through to WWII.
Indented line No.1 is to the east of Garrison Point Fort. Traces of gun emplacements can be found here and blocked embrasures, also one gun emplacement that is in good condition. A WWII searchlight emplacement has also survived and next to the fort are a gun cotton store and an engine room which was originally a magazine. Underneath is a shelter called “The Bunker”, also surviving is a side arms store.
Indented line No.2 has mostly been damaged by new buildings. There is a cartridge store at the western end and underneath the gun battery is a room marked on an 1899 plan as the north test room, which would have been used as a control centre for a submarine minefield. The gun battery (Albemarle Battery) was built in the 1899, it has four gun emplacements with shelters, cartridge, shell, coal and artillery stores below them. The two easternmost gun emplacements were used in WWII. In front of this battery is a small ruined square building on the beach, this was a machine gun emplacement.
Centre Bastion also known as Martello Battery. This bastion has three impressive towers, two of which were originally gun towers. They were built in 1913 and had 4.7” guns on top of them. The towers were made taller leading up to WWII, the westernmost one was used as an extended defence officer post commanding the controlled minefield, the easternmost one was used as an observation post with another gun on top. The square tower (central) was a fire control tower. In front of these towers is a WWI observation post which still has original shutters. This observation post is also the site of a practice battery. In front of the towers is a line of rooms, these rooms would have been used to store shells, cartridges and artillery / ammunition. The entrance to the rooms on the eastern end has the remains of the barrier, bench and coat hooks which is where the soldiers would have changed into safe clothing that couldn’t cause sparks. This is usually known as a shifting – lobby, in these rooms you can find the remains of an issue hatch. To the west is a short tunnel that leads to an ammunition lift. This tunnel has a bricked up issue hatch, on the other side of this you can see more magazines through the light recesses. There are two rooms in between these two entrances which have been bricked up but have been breached so you can see inside. These magazines and stores were built in the early 1800’s. Also on this bastion you can find a controlled mine field post and the remains of some gun emplacements. There is also a cartridge store to the east where the bastion meets Curtain Battery.
Curtain Battery is in between Centre Bastion and No.1 Bastion. There wasn’t much on this Bastion compared to the others - all that remains is a WWII search light emplacement and some concrete platforms to the west which held 4 x 40 pdr breech loading guns in 1895. It is possible the platforms for muzzle loading guns are still there but are now rubble.
No.1 Bastion is the most easterly of the bastions, situated opposite Tesco on the other side of the moat. It comprises of a WWI mine control post, an anti aircraft light machine gun emplacement, a direction finding mound, a gun pit, two brick WWII gun houses with emplacements and one open and one blocked Napoleonic magazine. Also two parts of the brick revetment wall can be found with gun emplacements present, a storeroom and another control post. It was also the site of the grand magazine built in 1801, in 1804 it was adapted for accommodation for the troops and demolished in 1955.
No.2 Bastion is within the steel mill and is still recognizable. It is partly surrounded by a moat, no gun emplacements remain but the military hospital does remain on site and is used for offices for the steal mill.
No.3 Bastion is within the steal mill, and mostly demolished. All that remains is part of the moat, now used as a cooling pond.
No.4 Demi Bastion is also in the steel mill grounds, it was on the corner between the moat and the sea. All that remains is one gun emplacement at an angle and one set of flanking emplacements.
Also in this area (Tesco car park) was another gun battery. It was named Ravelin Battery and had two 9.2” guns, the guns were installed in 1906 with the test firing occuring in October 1908, December 1909 and August 1913. These test shots caused windows to shatter and plaster ceilings to collapse in homes across the town in spite of precautions being carried out to prevent this the guns were removed in 1956. The battery was also used by No.2 Barrage balloon Battalion during WWII with the RAF being billeted to the site. The battery was used at the end of 1959 in a Territorial and Civil Defence exercise where the Lifeguard Corps were invited to join in. The exercise involved simuating the aftermath of a nuclear attack. Stretchers were attached to rope and people were lifted from the top of the Ravelin Battery and lowered to the ground, people were also lifted through the windows and doors of the barracks in No.1 Bastion with smoke bombs being used. The training was done in total secrecy. Ravelin Battery was demolished in 1993 when Tesco bought the land and built a new store.
Main picture supplied by Roger Betts. Thank you!