General Background
In April 1940, Germany invaded Denmark and Norway. Following the
withdrawal of the British Expeditionary Force from continental
Europe with the evacuation from Dunkirk and the fall of France at
the end of May 1940, Britain was effectively surrounded by occupied
territory. The Nazi-Soviet Pact which partitioned Poland meant that
Germany could concentrate forces in the west. The threat of an
invasion of the British Isles was high.
We now know that the German plan for invasion (Operation
Seelowe – “Sea Lion”) involved the short sea crossing at the
eastern end of the Channel. But at the time, it was believed that
the threat of invasion by air or sea could materialise almost
anywhere. Certainly the possibility of forces crossing from Norway
and Denmark could not be discounted; and eastern Scotland was
fortified against this eventuality.
Defences took two main forms. Around the shore the so-called
“Coastal Crust” was formed. Using fixed defences such as
pill-boxes, trench-lines, concertina wire, minefields and anti-tank
blocks, the areas of the coast judged vulnerable to invasion were
hardened. Areas where glider-borne forces could land were also
interdicted using networks of large upright poles. These fixed
defences tell only part of the story. Until recently it was not
generally known that the British authorities were also committed to
using chemical weapons to defend against invasion. Airfields near
coastal areas held stores of mustard gas and air units based there
were secretly tasked with delivering the gas in aerosol form over
the beaches if the invasion threat materialised. One of the
airfields and units so charged was No 614 Squadron at
RAF Macmerry
Inland, lines of fixed defences, usually arranged along natural
obstacles such as rivers or canals, were set up as “Stop Lines” to
hold and slow invading forces once ashore. East Lothian had no
designated Stop Lines. However, McKryton has set up a series of
caches in Fife to mark elements of the Fife Stop Line which gives
an excellent picture of how defences would be managed to slow and
destroy invading forces. A Bookmark list of these caches is
here.
There are two related websites which deal with the Second World
War in East Lothian. One is run by the
East Lothian Museums Service. The other relates to a two-volume
book “East Lothian at
War” (Volume One is now out of print.)
This article in Wikipaedia gives a helpful summary of British
anti-invasion defences.
Hedderwick Glider Poles
Park around N 56°00.009 W 2°33.651 in the large parking
area for the John Muir Country Park. You will already have noticed
that you can combine this cache with several others in the
area!
This cache is best visited at low tide when you can see the
extent of the network of glider poles in the sands of the Tyne
Estuary. The cache itself is accessible at all stages of the tide.
Tide tables can be consulted
here.
When the tide goes out, an extensive area of flat sand is
exposed at the mouth of the Tyne. It could have formed a natural
landing ground for glider-borne invasion. So a network of poles was
erected across the whole area. You can still see the poles
(although most are now heavily eroded) and the concrete bases which
supported them. Some anti-glider poles were timber. Many of the
poles in the Tyne Estuary are square sectioned reinforced concrete.
Close to the cache site is a fallen pole which should be visible at
most stages of the tide and which gives a good idea of the
construction of these obstacles.