Second World War defences at Thorneycroft Wood

Summary

A section of the Second World War perimeter defences of the Guildford nodal point, comprising an anti-tank ditch, concrete anti-tank pimples (dragon's teeth), eight rifle pits, and remains of barbed wire entanglements.

Reasons for Designation

The Second World War defences at Thorneycroft Wood, Stoke Park, Guildford Surrey, of around 1941 to 1942, are scheduled for the following principal reasons:

* Period: anti-tank defences were an important component of the nation’s defence policy adopted to resist invasion during the Second World War, and are therefore highly representative of this period;

* Rarity: once numerous, these defences are a rare surviving example of a well preserved section of a perimeter anti-tank defence to a Second World War nodal point;

* Documentation: drawn plans of the defences were produced in 1943 soon after their completion, and extensive non-intrusive archaeological research has been carried out on site, including a photographic survey and analysis of LiDAR imagery;

* Group value: collectively the anti-tank pimples, anti-tank ditch, and weapons pits form a cohesive ensemble;

* Survival: the defences are well preserved and readable as both upstanding structures and partially in-filled features;

* Diversity: the defences are a good example that demonstrates the diversity in their design and construction, and how they made use of the topography and natural barriers;

* Potential: the site has the potential to enhance our understanding of the construction, function, and use of this type of Second World War defensive line.

History

Following the fall of France in 1940, Britain was faced with the prospect of invasion. To counter the threat of a ground war fought across the country, defences were hastily erected along the coast and then inland, the latter involving a complicated pattern of linear stop line defences and area defence based around strategically important towns and villages, known as nodal points.

Guildford was designated as a ‘Category A’ nodal point which expected that the town should contain supplies to hold out for seven days, with water for four days, and would act as a stronghold in the event of invasion. It was also required to have an all-round defensive perimeter including anti-tank obstacles where possible. These defences were intended to be capable of halting, or at least delaying, a German advance until mobile units of the British Army could be deployed. The defence works were constructed to take advantage of the topography and any natural barriers such as rivers, woodland, and marshes. Where this was not possible, deep anti-tank ditches were dug, supported by a variety of other defence works including obstacles, pillboxes, weapons pits, and trenches, with considerable improvisation and variation in design occurring.

Thorneycroft Wood formed the north-eastern corner of the defensive perimeter to the Guildford nodal point, which was decided upon in November 1941, with work starting soon after. This section of the perimeter ran south from the River Wey, through Thorneycroft Wood, and across Stoke Park toward the New Guildford Railway line, defending the eastern approach to Guildford, and including a roadblock on the Guildford and Godalming Bypass (now Parkway, A25). Construction of the defences was initially undertaken by 577 Army Field Company of the Royal Engineers, with 578 Army Field Company taking over in January 1942, completing the work a month later. The defences were manned by the 4th Guildford Battalion Surrey Home Guard, who were raised by Colonel G.W. Geddes in May 1941.

The Thorneycroft Wood section of the defences comprised an anti-tank ditch cut on an angular curved north-west trajectory from Parkway, terminating at a line of concrete anti-tank pimples (colloquially known as dragon’s teeth) running west, perpendicular to the ditch, down the steep slope to the River Wey. Alongside the anti-tank measures was a corresponding inner perimeter barbed wire entanglement to hinder infantry movement. Within the woodland of the defended area was a Northover projector (an improvised 2.5-inch anti-tank weapon), a spigot mortar emplacement (a 29mm anti-tank weapon, also known as the Blacker Bombard), and eight rifle pits.

The design and construction of most defensive works at the time were set out in various Military Training Pamphlets published by The War Office and Home Guard Instructions published by the Home Office. Whilst publications such as these would have established some consistency around the country, there was a degree of adaptation in the construction of defences for their immediate environment and circumstances, as appears to be the case at Thorneycroft Wood.

Details

PRINICIPAL ELEMENTS: a section of the Second World War perimeter defence of the Guildford Nodal Point, comprising a section of an anti-tank ditch surviving as an earthwork and infilled buried remains, eight rifle pits surviving as upstanding remains, earthworks and infilled buried remains, as well as upstanding concrete anti-tank pimples (dragon's teeth).

DESCRIPTION: located within Thorneycroft Wood, the anti-tank ditch runs on a broadly south-east to north-west axis between the pedestrian crossing on Parkway (A25) to the south and the concrete anti-tank pimples (dragon’s teeth) to the north, appearing as a shallow linear depression.

The pimples run on an almost east-west axis between the anti-tank ditch to the east and the River Wey to the west. The line is approximately 72m in length and 10m in width, comprising rows of five pimples spaced at approximately 2.3m centres. Each pimple is pyramidal measuring 0.9m by 0.9m at the base, 0.3m by 0.3m at the top, with around 0.6m above and 0.6m below ground. Both end rows of pimples (to the east and west) appear to have been constructed with surrounding concrete pads. The flat top to most of the pimples has remains of an angle iron that was embedded vertically, probably to allow barbed wire to be attached.

The rifle pits vary in shape and size, but most appear to be rectangular and positioned to take advantage of the topography or for clear sight across the anti-tank ditch. Each rifle pit would have likely been approximately 1.0m to 1.2m deep from its elbow ledge, with an overall depth of around 1.4m from parapet level. The rifle pits are lined with cement-filled sacks to form the walls and elbow ledge. There are eight rifle pits in total, described with approximate locations and dimensions below:

A chevron shaped rifle pit located at TQ00275091, just south of the eastern end of the line of pimples and orientated to face the intersection between the pimples and the anti-tank ditch. The rifle pit is lined with cement-filled sacks and has longer outer dimensions of 3m and 4.1m, by 1.8m wide. The inner dimensions of the elbow ledge are 2.4m and 3.2m respectively, by 0.6m wide, and it has been infilled to 0.3m.

Slightly further south on the eastern edge of the site at TQ00285089 and overlooking the anti-tank ditch is a rectangular rifle pit, appearing as 0.1m deep depression with remains of cement-filled sacks.

Located almost centrally and around 20m south of the anti-tank pimples on a bluff overlooking the River Wey at TQ00255089 are two large rectangular rifle pits lined with cement-filled sacks. One rifle pit has outer dimensions of 3.5m by 2.4m, with inner dimensions of the elbow ledge are 1.7m by 0.7m and infilled to 0.7m. The second has outer dimensions of 5.6m by 2.4m and infilled to 0.6m.

To the west of the site at TQ00215088 are a cluster of three rifle pits likely commanding the lower approaches to the rear of the anti-tank defences near to a bend in the River Wey. All three rifle pits are rectangular, collectively loosely forming a T-shape, and appearing as 0.3m deep depressions with remains of cement-filled sacks and angle irons.

The southernmost rifle pit is located at TQ00295084 and was probably intended to cover the rear of the roadblock on the Guildford and Godalming Bypass. It is rectangular in shape with outer dimensions of 3.1m by 1.9m and appearing as 0.2m deep depression with remains of cement-filled sacks.

EXCLUSIONS: post-Second World War gates, fencing, and the timber-edging to the footpaths are excluded from the scheduling, although the ground beneath them is included.

Sources

Books and journals
Foot, W, Beaches, Fields, Streets and Hills: the anti-invasion landscape of England 1940 (2006),
Collyer, G, Rose, D, Guildford: The War Years, 1939-45 (1999),
Geddes, G W, The Guildford Home Guard (1944),

Websites
Through the dragon’s teeth: a remarkable set of Second World War defences in Guildford, accessed 05/09/2025 from https://www.exploringsurreyspast.org.uk/through-the-dragons-teeth-a-remarkable-set-of-second-world-war-defences-in-guildford/
Online viewer for the Extended Defence of Britain Database, accessed 05/09/2025 from https://edob.mattaldred.com/

Other
A map dated 1942-1943 depicting the Stoke Park Home Guard defences (Surrey History Centre ref. 1293)
The War Office (1940), Field Engineering (All Arms) Military Training Pamphlet No.30 Part III: Obstacles (provisional)
The War Office (1944), Infantry Training Part VIII - Fieldcraft, Battle Drill, Section and Platoon Tactics
Shepheard, C and Crocker, A (2004) Second World War defences in Surrey
War diary for 578 Army Field Company of the Royal Engineers for January to June 1942 (National Archives reference WO 166/8236)

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