Battery Heerenduin is situated at the estuary of the North Sea Canal which runs towards the port of Amsterdam and its industry. To defend the canal the Dutch build this defensive position in 1939 and equipped it with 7,5 centimetre guns. When Hitler’s armies invaded and conquered the Netherlands during Fall Gelb they immediately started to control key objectives. The port of Amsterdam was included. The Dutch already build defences near the canal estuary and on the island in the North Sea Canal which the Germans refer to as Kernwerk – Central building. They build a huge defensive position with inland defences, island defences, coastal batteries and flak batteries and called it Festung IJmuiden. Fortification IJmuiden was divided into three parts, Kampfgruppe Nord, Mitte and Süd. The heavy coastal battery Heerenduin lies in Kampfgruppe Süd (battle group south). The Battery was controlled by the Kriegsmarine. The coastal battery was designated as M.K.B. 81 or ‘Marine Kusten Batterie 81’. It is also refferd to as Widerstandsneste 81 Heerenduin, W.N. 81 Heerenduin.
Change of Name
After two years of service the Kriegsmarine decided to expand the battery and upgrade it to the Atlantic Wall standards. The upgrade started end 1941 and continued in 1942, it involved some name changes for the coastal Battery. It started out as the Süd Battery, south battery. In 1942 the name was changed into Batterie Prien, named after the famous Günther Prien a very successful Uboat ace. He sank 31 ships during World War Two and was a nightmare to every British sailor. With his U-47 he sank the HMS Royal Oak at Scapa Flow which gave him the nickname “The bull of Scapa Flow”. On 7 March in 1941 fate decided otherwise for Günther Prien, Günther and his crew were sunk by the HMS Wolverine west of Ireland. Günter Prien was the U-boat commander first who received the Knight’s Cross of the Iron Cross with Oak leaves, he was the highest decorated U-boat commander of his time.
During this period four 17 centimetre ship guns were placed in opens gun positions. Later it was named ‘Seeziel Batterie Südmole’, Seeziel means ‘Sea Targetting Battery’. During 1943 the name was changed to Batterie Heerenduin, which it kept during the length of the war.
Seeziel Batterie Heerenduin
The Seeziel Batterie Heerenduin was equipped with four 17 centimetre ship guns which fired 62 kilogram shells and had a reach of 20 kilometres. The guns were placed in closed gun emplacements named Regelbau, standard bunkers construction of the M272 type. In between was a fire control bunker of the Regelbau M178 type with flanking machine gun bunkers type 681 together with a flanking gun position 681. The gun position on the beach housed a 7,5 centimetre gun with a reach of 11 kilometre. Four open gun emplacements were added to the Battery. Three ammunition bunkers, two smaller types 134 and a bigger Fl246 type were constructed a bit to the back behind the gun positions. On the northern and southern tip of Battery Heerenduin were anti aircraft position called Flakstand. The personnel bunkers completed the battery with Regelbau 451a and 451b. The Batterie was protected with minefields, barb wire defenses and infantry. it was part of the K.V.A. Amsterdam, M.A.A. 4/201, or the fourth battery of the Kriegsmarine in section 201. To the south FLAK Batterie Olmen protected Heerenduin.
Festung IJmuiden was divided into multiple sections. In the middle of the canal, leading towards Amsterdam and the industry with blast furnaces, there is an island and further upstream is a ship lock. The Dutch build a fortress on the island and after the takeover by the German army it was upgraded to the new German standards. Festung is the German word for Fortress. The north of the canal was under control of Kampfgruppe Nord, battle group north. The centre, the canal, industry and harbours deeper inland were part of Kampfgruppe Mitte, and Kampfgruppe Süd, battle group South controlled the area south of the canal. All three sections were split into smaller Widerstandsneste, more than 75 different defensive positions of various sizes were constructed. The Kriegsmarine was in control of Festung IJmuiden but sections of the Luftwaffe and the Wehrmacht had their detachments inside the battle groups.
In the three sections were coastal batteries, FLAK batteries, radar posts, anti tank positions, search light posts, MG nests and flamethrower positions. All were protected by anti tank walls and ditches, mine fields, barb wire defences, concrete dragon teeth barricades and so forth. Inland they sealed off the Festung with Anti tank walls complete with a movable concrete door named a Walzkörpersperre. Stationed on the inland defences were the little remote controlled Goliath tanks to be sent from a pillbox towards an advancing enemy tank, they were detonated while driving under it.
To house these thousands of men who occupied the Fortress whole bunker villages were build. The entrance towards the canal was partly sealed off by the Dutch passengers ship ‘J.P. Coen’ which the Germans sank in the Canal, making it almost impossible for bigger ships to enter the canal. Beside the gun and personnel positions the Kriegsmarine ordered two Schnellboot bunkers in the harbour. These could hold about 30 boats and had a dock for repairs. One was damaged by Allied air raids and the other was never finished. The fast attack boats were heavily armed and could reach a speed of almost 90 kilometres per hour (48 knots), they carried torpedo’s and were used in small groups for lightning fast attacks. The Schnellboot was also known as E-boat or S-boat.
To get a clear line of fire for the batteries and fire control the German army demolished over 3150 houses and 150 other buildings, schools and churches. The inhabitants were evacuated. The Festung IJmuiden had a area of 20 square kilometres and included three different towns, IJmuiden, Driehuis and Wijk aan Zee. The latter was evacuated in 1944. All inhabitant were forced to leave their homes due to the radar post the Germans build here. Radars built near Wijk aan Zee are the Mammut FuMO 52 with a reach of 300km, two Würzburg Riese radars reach 60km, a Freya FuMO 1 reach 20km, Renner 1 FuMO 11 reach 70km.German radars were used for defence and offense, from plane and ship detection to anti aircraft gun and coastal gun aiming aid and some types could navigate bomb runs to their target. (FuMO – Funkmeßortungsstellung – Radio position detection and measurement device). Together there were about 1300 bunkers inside Festung IJmuiden.
Today the battery can be freely visited. There is a museum next to it but the gun emplacements and Fire control bunker are left open in the dunes. From the gun emplacements you can see the huge Schnelboot bunker in the harbor.