Pair of Second World War concrete roadblock plinths east of Hoo St Werburgh

Summary

Pair of concrete roadblock plinths, erected in 1940 as part of the Hoo Stop Line anti-invasion defences.

Reasons for Designation

The pair of Second World War roadblock plinths east of Hoo St Werburgh, Kent, are listed at Grade II for the following principal reasons:

Historic interest:

* as part of a coherent and legible group forming part of an important defensive ‘stop line’ protecting the heavily militarised Hoo Peninsula;

* the group contributes eloquently to an understanding of the wider defence policy adopted to resist invasion during the early and critical stages of the Second World War.


Architectural interest:

* the roadblock plinths are a relatively rare survival of this important element of the anti-invasion defensive structures and are of an uncommon type.

Group value:

* with other designations of this part of the Hoo Stop Line, particularly the nearby associated type 24 pillbox.

History

The building of a national network of anti-invasion defences to protect against German invasion began in June 1940 following the defeat of British forces in Europe and the return of many troops from Dunkirk. General Sir Edmund Ironside, who was appointed as Commander-in-Chief Home Forces at the end of May 1940, was responsible for planning the construction of a system of anti-invasion defences. On the 15th June 1940, plans were issued for the construction of inland anti-tank systems. Ironside was particularly concerned with halting the movement of Panzer and motorised forces following a successful landing, since the rapid advance of German forces had been a decisive factor in the fall of Holland and Belgium. Ironside planned a series of static defences, consisting of fortified nodal points and linear ‘stops’, which would curtail the progress of tanks and create zones within which an enemy could be contained. Stop-lines were essentially anti-tank obstacles intended to check the advance of fast moving columns of armoured troops and they were also intended as prepared battlefields for the Field Army to defend in the event of invasion.

The principal stop-line, the GHQ (General Headquarters) Line, ran from the North Somerset Coast to the east of London and then, parallel with the east coast, to Yorkshire. The 128km long Newhaven to Hoo stretch of the GHQ line was built by Eastern Command of the Home Forces during July and August 1940 and was intended to hinder a German advance from the beaches in Kent and Sussex. The Hoo section stretched from the northern bank of the River Medway, near Hoo St Werburgh, to Higham Marshes, near Cliffe, on the southern bank of the River Thames. It was partly intended to protect Chatham dockyards from possible enemy landings on the Isle of Grain or Allhallows and to reinforce the defences around the Lodge Hill and Chattenden ordnance depots. It took the form of an artificial anti-tank ditch supported by pillboxes, anti-tank rails and roadblocks. The War Office plan for this line indicates a total of sixty infantry and eighteen anti-tank pillboxes enclosing the higher ground containing the Lodge Hill and Chattenden. Each individual component would have been encircled in barbed wire for extra protection. There were probably also other earthworks in further support which are now lost, such as slit trenches.

The Hoo peninsula was a heavily militarised zone during the Second World War with Hoo itself designated as a defended village in 1941 with its own garrison. Troops from the Gloucestershire Regiment were responsible for defence in the Hoo sector during late 1940 and early 1941 with units of the 14th Battalion Kent Home Guard manning the pillboxes. From August 1940, when General Sir Alan Brooke succeeded Ironside, work on the GHQ line ceased in favour of a more mobile defence approach. The Hoo Stop Line was maintained as a fortified position until mid-1941 when orders stated that the GHQ line on Hoo was not to be defended in the event of invasion, although Hoo and other defended villages were to be garrisoned. By May 1943 discussions were being held to infill the anti-tank ditch and the Hoo section was backfilled by May 1944, although a section at the southern end where the ditch meets the Medway remained unfilled. At the end of the war the concrete defence structures were abandoned but often not removed.

Details

A pair of concrete roadblock plinths. Built in 1940 as part of the Hoo Stop Line, in response to the threat of a German invasion during the Second World War.

MATERIALS: reinforced concrete.

DESCRIPTION: the plinths are situated to the east of the village of Hoo St Werburgh, either side of a track running north from Stoke Road at NGR TQ7890772826. Each plinth is a substantial rectangular concrete block, set into the ground and around 1.7m in height, 4m in length and 1.2m wide. The plinths have one tapering face to the south and a deep slot dividing the plinth in two and which would have housed a horizontal steel rail, often reused railway rails, providing a strong but removable barrier. The plinths were constructed of concrete poured into shuttering constructed from corrugated metal sheeting, the imprint of which provides the blocks with a textured surface.

Sources

Books and journals
Osbourne, M, Defending Britain - Twentieth-Century Military Structures in the Landscape, (2004)
Osborne, M, Pillboxes of Brtian and Ireland, (2008)
Truscoe, Krystyna, Hoo Peninsula, Kent: Second World War Stop Line, Hoo St Werburgh to Higham Marshes, (2014)

Websites
Pillbox Study Group: Roadblocks, accessed 17 August 2020 from http://www.pillbox-study-group.org.uk/other-wwii-defensive-structures/roadblocks/

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