Wikipedia
The Cointet-element, also known as a Belgian Gate or C-element, was a heavy steel fence about three metres wide and two metres high, typically mounted on concrete rollers, used as a mobile anti-tank obstacle during World War II. Each individual fence element weighed about 1,280 kg but was movable (e.g. with two horses) through the use of two fixed and one rotating roller. Its invention is attributed to a French colonel, Léon-Edmond de Cointet de Fillain (1870-1948, later to become general), who came up with the idea in 1933 during the run-up to WWII, as to be used in the Maginot Line. Besides their use as barricades to the entrances of forts, bridges and roads, the heavy fences are best known for their use in the Belgian Iron Wall of the KW-line and their re-use as beach obstacles on the Atlantikwall.
The Cointet-element formed the main barricade of the Belgian KW-line, a tank barricade that was built between September 1939 and May 1940. Following tests, the Belgian army accepted the Cointet-elements in 1936 after slightly altering the design by the addition of eight vertical beams in the front frame to avoid penetration by infantry. On 13 February 1939 and 24 July 1939 the first tenders were called for ten groups of 500 Cointets each. A total of 77,000 pieces were ordered by the Belgian Ministry of Defence and produced by 28 Belgian companies with 73,600 pieces delivered.
Thousands of Cointets were installed on the KW-line between the village Koningshooikt and city Wavre to act as the main line of defence against a possible German armoured invasion through the heartland of Belgium, forming one long iron wall. The Cointet-elements were placed next to each other in a zigzag-line and connected with steel cables. Near main roads they were fixed to heavy concrete pillars that were fixed into the ground to allow local traffic passage. In May 1940 however, due to a relocation programme, the elements didn't form a continuous line and thus were easily by-passed by 3rd Panzer Division and 4th Panzer Division.
After the German victory in Belgium on 28 May 1940, the Belgian Gates were reallocated across Europe to serve as German barricade elements on roads, bridges and beaches. The Germans gave it the name C-element. Large numbers of gates were brought to Normandy during the construction of the Atlantikwall to be used alongside the other varieties of beach obstacles. Instead of connecting them, the Germans used them singly next to other items, especially at the low tide line. They were also put on the dikes next to bunkers. Notes from 1944 cite the placement of 23,408 Cointets over 4340 km of coastline. With many more still present in Belgium after D-Day, the Allies had great difficulty passing them in the last months of the war.
The gate illustrated has been rigged with explosive "sausages" for demolition using a technique described in the article on UDT.