The outer London anti-tank defence line
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| A type 24 pillbox in the fields of Boltons Park Farm owned by the RVC Image by the North Mymms History Project released under Creative Commons |
One is standing in the corner of a field at Boltons Park Farm south of Hawkshead Road the other is in the grounds of Queenswood School. Both are type 24 boxes and are on private land with no nearby public access.
The North Mymms History Project has acquired images of both pillboxes thanks to the cooperation of staff at Boltons Park Farm and Queenswood School.
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| The type-24 pillbox in the grounds of Queenswood School, North Mymms Image courtesy of Dr Wendy Bird, Archivist at Queenswood School |
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| The two North Mymms pillboxes are 1.3km apart |
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| The collapsed entrance to the type 24 pillbox in the fields of Boltons Park Farm Image by the North Mymms History Project released under Creative Commons |
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| The type-24 pillbox in the grounds of Queenswood School, North Mymms Image courtesy of Dr Wendy Bird, Archivist at Queenswood School |
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| The type-24 pillbox in the grounds of Queenswood School, North Mymms Image courtesy of Dr Wendy Bird, Archivist at Queenswood School |
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| The type-24 pillbox in the grounds of Queenswood School, North Mymms Image courtesy of Dr Wendy Bird, Archivist at Queenswood School |
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| The type-24 pillbox in the grounds of Queenswood School, North Mymms Image courtesy of Dr Wendy Bird, Archivist at Queenswood School |
Fortress Hertfordshire
Former local resident, Jim Apps, built a website about the local wartime defences called Fortress Hertfordshire. He also wrote a feature for our old local history section about his site. Unfortunately, that site is no longer live, and all Jim's work and images has been lost.
This piece includes part of what Jim wrote in 2003, with new images taken on October 19, 2018, and updated information.
Jim Apps wrote that in 1940, as the German army swept across mainland Europe to the shores of France, Britain was in imminent danger of invasion. Only the English Channel stood in the enemy's way.
"As the Germans occupied France, Norway and the low countries, the length of our shoreline that had to be defended increased dramatically. The fixed lines of defences, built to prevent invasion from the sea, were known as the General Headquarters (GHQ) Lines.
"Behind the coast, the threat of airborne landings required the guarding of more than 1,500 vulnerable points, such as airfields, army establishments and centres of military production.
"By far the most vulnerable area, and the most important target for the German Army, was London. To prevent the capture of London and everything it contained, a fixed ring of anti-tank ditches and pillboxes were built as a final line of defence. This was known as the outer London stop line, or Outer London Defence Ring.
"The line passed through the southern part of Hertfordshire, from Watford to Cheshunt, and much of it still remains today."According to Jim Apps, the remains of the Outer London Defence Ring can just be made out running to the north and east of the North Mymms pillbox, visible in the image below running along the line of oaks behind the type 24 pillbox.
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What is thought to be the remains of the anti-tank ditch running along the oaks Image by the North Mymms History Project released under Creative Commons |
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| The collapsed entrance to the type 24 pillbox in the fields of Boltons Park Farm Image by the North Mymms History Project released under Creative Commons |
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| The north face of the type 24 pillbox in the fields of Boltons Park Farm
Image by the North Mymms History Project released under Creative Commons |
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The interior of the type 24 pillbox in the fields of Boltons Park Farm Image by the North Mymms History Project released under Creative Commons |
Jim Apps spent a great amount of time and effort researching and writing about this important part of our military history. His website, Fortress Hertfordshire, was, he wrote at the time, "my attempt to make some of our important historical structures available to a wider audience".
The site had 40 images of tanks traps and pillboxes in Northaw, Cuffley, Potters Bar and Watford, along with information explaining their importance to the defence of Britain. Jim wrote:
"For example, on the north side of the Ridgeway in Northaw, to the west of the Great Wood, is a pillbox. Opposite it, on the south side of the road, is a set of anti-tank blocks.
"In front of the pillbox are the remains of the anti-tank ditch. This would have formed part of a roadblock.
"Close to another pillbox in Northaw is an ammunition store used by the Home Guard to store self-igniting phosphorous anti-tank grenades or explosives.
"One of the picture on Fortress Hertfordshire shows the remains of what is thought to be a store for damp-sensitive items such as fuses. These stores are unusual in Hertfordshire.
"Also, on the east side of Great Woods is a short length of concrete roadway, believed to have been the access to an anti-aircraft emplacement.
"About 100 yards from the Ridgeway's junction with Carbone Hill there are four anti-tank blocks, two on either side.
"Between these blocks, set into the road, are five rows of sockets into which steel rails could be placed, standing upright, to prevent tank access.
"Three of these rows still contain the original metal sockets. This type of roadblock is unique in the county."
The Swanley Bar tank traps
Jim also wrote about the importance of the tank traps at the junction of Swanley Bar Lane and the Great North Road at grid reference TL 26144 03171 and What3Words reference https://w3w.co/fuel.poker.dame. The photographs of the traps, taken in September 2018, are included below.
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| One of the Swanley Bar tank traps North Mymms Image by the North Mymms History Project released under Creative Commons |
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| One of the Swanley Bar tank traps North Mymms Image by the North Mymms History Project released under Creative Commons |
Nearby pillboxes
There are two more type-24 pillboxes on Potters Bar golf course to the south-west of the North Mymms pillbox.
The first is a distance of 1,678 ft (511 m) to the north of the public footpath (Hertfordshire right-of-way Potters Bar 005) that runs across the golf course at grid reference TL 24863 02396 and What3Words reference https://w3w.co/lanes.rice.trader. See the first two images below.
The second is another 1,796 ft (547 m) further west, close to the stream running alongside the footpath to the east of the railway line at grid reference TL 24485 02345 and What3Words reference https://w3w.co/notice.beast.liner. See the third and fourth image below.
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| A pillbox on Potters Bar golf course Image by the North Mymms History Project released under Creative Commons |
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| A pillbox on Potters Bar golf course Image by the North Mymms History Project released under Creative Commons |
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| The pillbox close to the railway line Image by the North Mymms History Project released under Creative Commons |
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| The pillbox close to the railway line Image by the North Mymms History Project released under Creative Commons |
Editor's Note
You can read more about local defences in an article on this site about the North Mymms tank traps, another article about the North Mymms spigot mortar emplacements, and one about the Bell Bar Tett turret and tank traps.
There are more articles about the war years, including a feature on the North Mymms Rifle Range, a POW camp in Welham Green, and a booklet about life 'On The Home Front' in North Mymms during the war years.
There is also a feature about young evacuees from London being sent to live in Brookmans Park.
Comments and information welcome
If you have anything to add to this feature, or just want to add your comments, please use the comment box below.