This browser is not fully supported by Historic England. Please update your browser to the latest version so that you get the best from our website.

Observation post 140m north west of Ridlees Cairn

List Entry Summary

This monument is scheduled under the Ancient Monuments and Archaeological Areas Act 1979 as amended as it appears to the Secretary of State to be of national importance. This entry is a copy, the original is held by the Department for Culture, Media and Sport.

Name: Observation post 140m north west of Ridlees Cairn

List entry Number: 1021028


The monument may lie within the boundary of more than one authority.


District: Northumberland

District Type: Unitary Authority

Parish: Alwinton


Grade: Not applicable to this List entry.

Date first scheduled: 06-Oct-2003

Date of most recent amendment: Not applicable to this List entry.

Legacy System Information

The contents of this record have been generated from a legacy data system.

Legacy System: RSM

UID: 32787

Asset Groupings

This list entry does not comprise part of an Asset Grouping. Asset Groupings are not part of the official record but are added later for information.

List entry Description

Summary of Monument

Legacy Record - This information may be included in the List Entry Details.

Reasons for Designation

The Army Training Estate Otterburn (ATEO) is one of seven Army Field Training centres in the UK and is the largest single live firing area in the country. It has been operational since 1911 when the War Office acquired about 20,000 acres (8094ha) of land in Redesdale, Northumberland to create a seasonal tented camp and artillery range for the training of the newly formed Territorial Forces. The pattern of artillery firing from Easter to October fitted in with local sheep farming practices, and byelaws to control access during live firing periods were introduced in 1916. A period of intense training occurred during World War I to prepare both artillery and infantry units for war, including the construction of a sector of front line trenches at Silloans to practice infantry companies in the routines of defence, control of overhead artillery fire and relief in the line. After World War I the previous pattern of training was restored and continued to 1939, the only change being that from horse drawn to lorry drawn guns in 1938. During World War II, the training area doubled in size with the acquisition and subsequent purchase of a further 20,000 acres (8094ha) to create a second Artillery Range and camp at Otterburn. In 1959 the Ranges were renamed as an All Arms Training Area and five infantry fire and manoeuver areas at Quickeningcote, Wilkwood, Davyshiel, Sills and Heely Dodd were constructed under the Thurlow Plan. From 1969 Otterburn was designated as one of seven Principal Training Areas in the UK and became increasingly used for fire and manoeuver training by infantry units supported by artillery, mortars, guided missiles and air to ground attack aircraft. Developments since 1969 have included the construction of another battle shooting area at Ridleeshope and a moving target railway system at Stone in the Mire for engagement by wire guided anti-tank missiles.

The observation post 140m north west of Ridlees Cairn survives well in an unmodified state with a range of its component features intact. It was constructed as one of a group of four bunkers, which represent a major phase of artillery training between World Wars I and II. These are rare examples of structures of this kind with the only parallel being single examples at Salisbury Plain and Okehampton Training Areas. Hence they are an important survival in the history of military training in England.


Legacy Record - This information may be included in the List Entry Details.


The monument includes the upstanding and buried remains of a bunker situated on the Otterburn Army Training Estate. The bunker, which served as an observation post known as OP 9, is now redundant, and is one of a group of four on the Training Estate situated in two pairs. The other three bunkers and Ridlees Cairn are the subjects of separate schedulings. The bunker was intended to provide shelter during training for parties of 16 Forward Observation Officers guiding artillery fire into the impact area from mobile guns placed outside. The exact date of its construction is uncertain but a similar structure, thought to provide a parallel for the four Redesdale examples, was constructed on the Okehampton Artillery Range in 1923/24. The bunker, which faces north to command views over the Redesdale Impact Area, is visible as a rectangular blockhouse with projecting triangular wings encased in an earth and stone mound. The blockhouse is constructed of reinforced concrete and measures 23m long, 2.5m wide and it stands to about 2.1m above ground level at its front face. The walls, which are splinterproof, are 0.45m thick. Four rectangular recessed embrasures 0.46m deep and 2.1m wide pierce its front face with a concrete lintel over, which projects 0.15m and is 0.5m high. The mound, which encases the bunker, is 8.5m wide and about 1.75m high. Its eastern end has been modified to form a ramped access to the roof. The ramp extends for a further 7m beyond the rear of the earthen bank where it is truncated by a vehicle turning circle.

Entry to the bunker is gained at the east end of the north face by a series of descending concrete steps, which project, 3.5m from the front face of the bunker. The stairway is protected on each side by a brick blast wall, which gives access to an offset passageway about 0.8m wide. Internally, the remains of a narrow wooden shelf that originally ran the full length of the bunker immediately beneath the line of embrasures survives at the east and west ends. Continuous raised wooden seating is also present along the length of the bunker where the operatives would sit to gain good vision. A drainage gully at floor level runs the length of the bunker immediately below the embrasures. It passes through the east wall of the bunker into a small drain within the offset passageway. The concrete base and flue opening of a potbellied stove are retained in the south west corner of the bunker and a field telephone is attached to the west end of the north wall. Evidence of the corrugated iron shuttering used in its construction is exhibited in the roof.

MAP EXTRACT The site of the monument is shown on the attached map extract. It includes a 2 metre boundary around the archaeological features, considered to be essential for the monument's support and preservation.

Selected Sources

Francis, Paul , (2002)
Thomas, Roger J C , (2002)

National Grid Reference: NT 84192 04428


© Crown Copyright and database right 2018. All rights reserved. Ordnance Survey Licence number 100024900.
© British Crown and SeaZone Solutions Limited 2018. All rights reserved. Licence number 102006.006.
Use of this data is subject to Terms and Conditions.

The above map is for quick reference purposes only and may not be to scale. For a copy of the full scale map, please see the attached PDF - 1021028 .pdf

The PDF will be generated from our live systems and may take a few minutes to download depending on how busy our servers are. We apologise for this delay.

This copy shows the entry on 22-Jan-2018 at 10:19:24.

End of official listing