Semington in World War II

Semington in World War II

You will have noticed the numbers of pillboxes surrounding Semington but why are they there? To answer this question we must turn to what was happening in World War 2 at the time. The defences were built in 1940, immediately following Dunkirk. 338,000 servicemen were rescued leaving their equipment behind. Britain lost a large part of its mobile warfare capability and resorted to static defence.

Defences were built along the beaches and around cities in preparation for what was considered an inevitable invasion. However, it was appreciated that the Germans would be able to manoeuvre around these and so a series of Stop Lines were constructed. The Blue Stop Line started at Whaddon and followed the course of Semington Brook to Semington, looping around a tank ditch surrounding the village before extending to Reading along the Kennet and Avon Canal. Whaddon was at the intersection of the Green and Blue Stop lines, with the Green Stop Line following the River Avon at this point. The primary purpose of the Blue Stop Line was to delay a German advance reaching the industrial midlands to buy time for what mobile forces Britain could muster to intercept the advance and for the Royal Navy to sever German supply lines.

Stop lines were a concept developed in WW1 and many senior generals, returning from the fighting in France, believed they were outdated because a breakthrough at one point would render the stop line ineffective, and they advocated defence in depth as being the best way to defeat German manoeuvre warfare. Consequently, the anti-invasion plans were revised but Semington remained an important defensive position, categorised as a Nodal Point Category C.  Such Category C nodal defences were expected to survive at least 24 hours of combat. As defences were removed from the Blue Line to be concentrated around Reading and to reinforce beaches, Semington stood out as one of the few defensive positions between Bristol and the western end of the Kennet and Avon Canal.

But why Semington? Semington’s defences remained important from their construction until 1944 when the threat of an invasion receded. The role of the defences was to deny German forces use of the A350, they were not there to defend the village.  The A350, which ran through the High Street until the bypass was opened in 2004, was considered a major arterial route the Germans might follow. Semington Bridge was not part of the UK counter manoeuvre plan and in the event of an invasion, the bridge was scheduled for early demolition. The villagers would have potentially found themselves with the German invading force advancing from the South and a demolished canal bridge denying them vehicle access to the north. The A350 was to be further blocked at Melksham and Chippenham.

There were concerns. The canal was shallow and it was feared that demolishing the bridge would create a ford or provide the foundations for a temporary tactical bridge with suitable approaches using the road. To deter the Germans from using this to advantage the village was designated a tank killing area. As the war progressed it was decided that to avoid the premature, ill-disciplined demolitions of bridges, to the detriment to the national road infrastructure, they would be blocked, not demolished. It is not known how this order affected Semington Bridge.

The village defences comprised a machine-cut, anti-tank ditch starting in the west on the canal at the swing bridge, extending around Semington, following Semington Brook east of Manor Farm before ending back at the canal. Building it around Semington avoided housing restricting the field of fire of weapons located in pill boxes. Life had to go on and four entrances enabled the ditch to be crossed.

The main route was, as it is now, down the High Street and accounts for the heavy gun emplacement pillbox to protect it. Another was where Pound Lane meets the track leading to the swing bridge. A third was at the end of St George’s Road beyond St George’s Court. The last was East of Manor Farm. Additionally there was a road block controlling access across the bridge. 6 pillboxes reinforced the ditch and a 6-pounder gun pit was positioned just north of the bridge. Finally anti-tank obstacles protected the aqueduct where the canal crosses Semington Brook, at the swing bridge and along the canal. The swing bridge would have been removed well before the Germans threatened it and it is likely that the obstacles were to hinder using the approaches to it, should a temporary bridge be constructed.

Typical Anti-tank Ditch

Except for two, the pillboxes were designed to house 2-pounder anti-tank guns . The one guarding the west end of the anti-tank ditch and one south of Chestnut Barn (Church Street), were built to defend against dismounted attacks which may have included an anticipated parachute landing.

The pillbox on the high street, differed from the others by including a room to protect infantry soldiers presumably there to prevent dismounted German troops from capturing it. At the northern end of the bridge, a 6-pounder gun pit was built.

The 6-pounder was considered an inferior gun to the 2-pounder, particularly for attacking tanks, but could additionally fire anti-personnel ammunition. The gun was not mounted within a pill box allowing it to swivel, covering a much larger area. The defences protecting access across the anti-tank trench were vertical rail obstacles comprising a grid of concrete sockets positioned in the ground; into each a removable vertical rail could be inserted in time of danger. A vertical rail obstacle was typically used in the chicane of road blocks protecting the approach to bridges and it is reasonable to suppose a similar defence protected Semington Bridge.

      6-Pounder Gun                                                                                                                                                                               2-Pounder Gun                   

Though we know the bridge was protected by obstacles any physical evidence of these has been removed. The slots into which the vertical rail would be placed in Pound Lane largely remain and I am told that one of the rails may also be there, yet to be found. Little remains of the one East of Manor Farm. Regrettably any evidence of the one in St George’s Road was lost when the cycle path was constructed. I have found no record of Semington’s defences being supplemented by minefields though there is minor evidence of barbwire entanglements. However, it is difficult to envisage the pillboxes providing a credible defence without them. Presumably these would not be put in place until a German advance proved a threat.

Semington is located in the area that was controlled by 6th Wiltshire Battalion, a home guard battalion, however Semington defences were supplemented by a Royal Signals lodger unit based in Trowbridge Barracks. It is believed this unit trained the intercept operators who would collect German radio traffic to be analysed by Bletchley Park. It is also likely the defences were built in the anticipation of the scarce guns being made available when needed, not in the certainty that they would.

Vertical Rail Anti-tank Device

During the war, evacuees from London arrived to be lodged with local families and go to school.  Nearby Melksham camp accommodated both British and American Air Force personnel and aircraft and gliders operated from Keevil airfield.  Life went on in the hope that Semington’s defences would never be needed.