References regarding the relation of the site to other defence sites. (1-4).

The Indented Lines preserve the only visible remains of the de Gomme works of 1669, when they formed the north-eastern side of the Sheerness Fort defences on the tip of the Sheerness peninsula. Originally called Gunners Battery, Dial Line and Long Lines they were renamed the Indented Lines after 1838. The Indented and Sheerness Lines (TQ 97 NW 109) were linked in 1827 with the construction of a sea wall between Minster Bastion on the Indented Lines and No.1 Bastion on the Sheerness lines and moated by 1848. By 1899 the Indented Lines mounted two 6 pdrs and twqo 12 pdr quick firers (QF's) around the same time that Albemarle Battery with four 12 pdr QF's. was built even though it was proposed in 1828. Two guns were still in operation in 1940 and a machine gun emplacement was built on the shore immediately north of its eastern QF emplacement by 1923. Abandoned in 1956.

The 17th century fabric of the Indented Lines is still visible in the lower part of the seaward face, composed of stone rubble and brick faced with Kentish Rag ashlar. It has a heavy cordon and at the angles of the lines, two moulded corbels in Portland Stone which originally supported bartizans. (5)

From the National Heritage List for England:
17th Century Defences: surviving portion of late 17th century fortifications designed by Sir Bernard de Gomme. Stretch if indented trace east of Garrison Point Fort. Largely faced in Portland ashlar to cordon. The brick parapet is later and together with the rampart had been remodelled and mutilated by 19th century gun positions. At three angles are moulded corbels which carried sentry boxes.

Indented Lines coastal battery located at TQ 913 756. By December 1902 it was armed with two 12-pounder and two 6-pounder quick-firing guns. It was disarmed circa 1914-1916. (6-7)

Aerial photography from 1978 show gun emplacements and battery observation post remaining in good condition. Ancillary buildings and structures also survived, and a coast artillery searchlight was located to the east and west. (8)

Historic England, Archive material associated with the Sheerness Lines (Archive). SKE56321.

<1> Sheerness Defences, Garrison Point Fort and the Indented Lines/ink survey (Graphic material). SKE6431.

<2> Sheerness Defences, Garrison Point Fort and the Indented Lines/overlay (Graphic material). SKE6432.

<3> Sheerness Defences, the Indented Lines (Bibliographic reference). SKE6439.

<4> RCHME: Sheerness Defences, Kent (Collection). SKE6533.

<5> Royal Commission on Historic Monuments in England, 1995, Sheerness: The Dockyard, Defences and Blue Town (Unpublished document). SWX6974.

<6> Dobinson, C., 2000, Twentieth century fortifications in England. Volume 6.2. Coast Artillery, 1900-1956 (Monograph). SWX23711.

<7> Dobinson, C., 2000, Twentieth century fortifications in England. Volume 6.1. Coast Artillery, 1900-1956 (Monograph). SWX23710.

<8> Twentieth century military recording project: World War Two Coastal Batteries (Unspecified Type). SWX20691.