Summary
Second World War roadblock, consisting of an anti-tank wall built of orthstats, set between two 'one-way' anti-tank ditches with counterscarp banks, and a dry-stone field boundary wall, adapted by the insertion of steel rail barrier sockets and three musketry loop-holes with an infantry slit trench to the rear.
Reasons for Designation
This Second World War roadblock is scheduled for the following principal reasons:
* Period: it contributes eloquently to an understanding of the broader defence policy adopted to resist invasion during the Second World War;
* Rarity: the roadblock is a rare example of an inland obstacle designed to control the flow of local traffic and to impede the movement of attacking airborne troops;
* Survival: the roadblock survives well and is readable, both as upstanding structures and as in-filled features:
* Diversity: the roadblock is a good example to demonstrate the diversity of designs and materials used;
* Potential: the roadblock has the potential to enhance our detailed understanding of the construction, function and use of this type of anti-invasion defensive structure during the Second World War.
History
World War II anti-invasion defences were prepared for the defence of Britain in the event of German forces invading the country. The initial defence schemes were devised in May 1940 by the Home Defence Executive set up under General Sir Edmund Ironside, Commander-in-Chief of the Home Forces, specifically to deal with all matters of home defence. At that time, the country was ill-prepared to oppose an invasion, due to the substantial losses of equipment incurred during the evacuation of the British Expeditionary Force from Dunkirk; necessitating the construction of static defence lines and localities. A series of successive lines of defence or 'Stop Lines' and defended localities were constructed, starting on the coastline (concentrating on the eastern and southern coasts) with subsequent lines inland, culminating in multiple rings around London. Limited defences were also prepared around potential ‘Drop Zones’ and ‘Landing Zones’ that could be used by paratroops and glider-borne troops, and roadblocks were built to inspect and control the flow of traffic.
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 natural barriers such as rivers, woods and marshes. Where this was not possible, deep anti-tank ditches were dug, up to 7m across, supported by a variety of other defence works including trenches, roadblocks, concrete pillboxes, weapons pits etc. with considerable improvisation and variation in design occurring.
Large expanses of open ground near to the coast, and inland strategic locations and industrial centres were obstructed to prevent airborne troops from being landed from aircraft. Baildon Moor was considered to be vulnerable to such a landing and defences were prepared to contain any attack, including the construction of a roadblock that barred Glen Road. The roadblock would have consisted of a series of horizontal steel girders that spanned the width of the road, slotted into a concrete block on the western verge and into sockets set into the dry-stone wall on the eastern side. The ground between the roadblock and Shipley Glen was obstructed by an anti-tank wall set between two ‘one-way’ anti-tank ditches, and the approach from Baildon Moor was covered by an infantry slit trench behind the dry-stone wall with three wide-splay small rifle embrasures cut into it. A ‘one-way’ anti-tank ditch is one that has a gentle slope to the counter-scarp and a steep near vertical scarp slope; there being only ‘one-way’ in or out, hence the name. Any vehicle attempting to cross the ditch would be tipped nose down into the base and would not be able to climb the steeper scarp side topped with the orthostat wall. The spoil from the excavation of the ditch was usually heaped into a counter-scarp bank, which obscured the ditch from view from any approaching vehicle, it also increased the depth of the ditch into which a vehicle or tank would drive. Given the nature of the construction of the defences, it is clear they were not intended to resist armoured vehicles, but would have been suitable for the control of civilian traffic and any light vehicles used by enemy airborne troops had they been landed by aircraft on the Moor. Baildon Moor was also used as a training area for novice tank crews, with practice firing loops laid at Dobrudden Farm and accommodation at Lower Crook Camp, which was associated with the main camp at Farnley Hall, Otley. With all of this military activity, the roadblock may have also have been used to control the flow of civilian traffic across the Moor during periods of training activity.
Details
Principal elements: Second World War roadblock, consisting of an anti-tank wall built of orthstats, set between two 'one-way' anti-tank ditches with counterscarp banks, and a dry-stone field boundary wall, adapted by the insertion of sockets to receive steel barrier rails and three rifle embrasures with an infantry slit trench to the rear.
Description: the roadblock built to obstruct an unclassified road called Glen Road, is situated at Bracken Hall Green, on the south-western side of Baildon Moor. The western side of the roadblock comprises an orthstat anti-tank wall set between two anti-tank ditches, in an area of common grazing land laying between the Bracken Hall Crags of Shipley Glen and the western side of Glen Road. The anti-tank wall consists of a 20m long, 2m wide, double row of orthostats, in-filled with earth and rubble, aligned roughly east-west, and varying in height from 1-2m. It appears to have been built to resemble prehistoric walling for camouflage purposes and sits between two ‘one-way’ anti-tank ditches. The ditch on the northern side is 3m wide and 1m deep, it has a slight counterscarp bank on its northern side and slopes gently down to the near vertical scarp beneath the orthostat wall; while the ditch on the southern side of the wall is 3-4m wide and 0.5m deep and also has a counterscarp bank. It is likely that both of these ditches have suffered from some degree of slumping and in-fill due to natural processes and colonization by scrub.
The field to the east of the roadblock is enclosed by a dry-stone wall, a 50m long section of this wall standing immediately to the east of Glen Road and including the curved section at the north-west corner of the field, forming part of the roadblock. An in-filled infantry slit trench which shows as a depression is situated in the field immediately behind the curved section of wall, which has three wide-splay rifle embrasures cut just above its base. Three blocks of timber each approximately 1.5m long by 0.25m square are laid end to end forming the lintels of the embrasures, which have been blocked with dry-laid stone. When the embrasures were inserted, the wall above the lintels was reconstructed and mortar was used to strengthen the stone joints. Two sockets with flat wrought-iron sheet lintels have been let into the side of the dry-stone wall opposite the orthostat wall and ditches; the sockets were for receiving the ends of the girders that formed the road block. To accommodate the sockets, the wall was reconstructed and mortar was used to strengthen the stone joints.
Extent of scheduling: the scheduling includes the full extent of the orthostat wall, the two ditches and associated counterscarp banks, a 50m long section of the dry-stone wall and the in-filled trench to its rear. The road is not part of the scheduled area; however, there remains the possibility of concrete sockets designed to receive steel rails that may be buried beneath the road surface.
