Fortified Sector of the Escaut The Fortified Sector of the Escaut ( " Secteur Fortifié de l ' Escaut " ) , also known as the Fortified Sector of the Schelde , was the French military organization that in 1940 controlled the section of the Maginot Line between the French border with Belgium and Valenciennes , a distance of about . Named for the Escaut River ( more commonly known as the Schelde ) , the Maginot line in the Escaut sector consists of a single position , the " petit ouvrage " Eth , together with its supporting casemate Jeanlain , as well as an upgraded fort of the Séré de Rivières system , the Fort de Maulde . The remainder of the sector ' s fortifications consist of blockhouses and casemates arranged along a line of principal resistance about behind the frontier , with a second line on the edge of the Raismes Forest . The Escaut sector and the Fortified Sector of Maubeuge were the final sections of the Maginot line to be authorized , and were termed the " New Fronts . " The Escaut sector was attacked during the Battle of France in late May 1940 , resisting for a few days . Concept and organization . Initial work in the sector established a series of casemates in the Raismes Forest , between Valenciennes and the Belgian border . The casemates were built by the " Commission d ' Organisation des Régions Fortifiées " ( CORF ) , the Maginot Line ' s design and construction agency . As the fortification of the Escaut Front was commenced later than the main section of the Line to the east , funds were restricted by the impact of the Great Depression , which had reached France . The plan was also affected by political considerations , in which the fortification of the Belgian frontier was seen as a betrayal of the French plan for forward defense on Belgian territory . Most of the Escaut blockhouses built in 1936 - 37 were built under local initiatives to designs by the Army Engineering Service " Section Technique du Génie " ( STG ) . The CORF lines in the Raismes Forest were augmented by lesser positions in the principal line of resistance constructed in 1936 - 37 . In 1940 a few hasty fortifications were built to the rear of Valenciennes under the authority of the Study Commission for the Fortified Zones ( " Commission des Études des Zones Fortifiées " ( CEZF ) ) . Ouvrage Eth is the sole Maginot fortification in the sector , two blocks linked by a deep underground gallery . A third block was planned but never completed , to be equipped with a 75mm gun turret , along with expanded support facilitites and a separate entrance block . A drainage tunnel of sufficient size for human passage linked Eth to the Casemate de Jeanlain , about away to the west . The Fort de Maulde was improved under the auspices of STG , with a unique casemate for 155mm Fillioux field gun . Work was begun on an underground link between the observation post and the 75mm and 155mm casemates in 1939 , but was never completed . Command . The Escaut sector was under the overall command of the French 1st Army , under the command of General Blanchard , which was in turn part of Army Group 1 under General Gaston Billotte . The SF Escaut was commanded by General Echard , then General Béjard from May 1940 . Description . The sector included , in order from west to east , the following major fortified positions , together with the most significant casemates and infantry shelters in each sub - sector : 54th Fortress Infantry Regiment ( " 54e Régiment d ' Infanterie de Forteresse ( RIF ) " ) , Lt . Colonel Delcure Raismes Forest Line ( CORF ) ( 108th CEO ) Resistance line ( FCR / STG ) : 107th CEO 106th CEO Second line in front of Valenciennes ( FCR / STG ) Second Position ( CEZF ) ( 1940 ) History . Battle of France . Following the surrender or evacuation of the Fortified Sector of Maubeuge to the east , the German 253rd Infantry Division began to bombard the Fort de Maulde on 20 May 1940 , reaching the fort with infantry on 23 May . Ouvrage Eth was bombarded starting 22 May , and invested tby infantry and close - range artillery the next day . Pressure was increased on 26 May , when Block 2 of Eth was damaged by the German 28th Infantry Division ' s artillery and Maulde ' s peripheral casemates were captured . Captain Dobos of Eth moved his garrison by a connecting drainage tuunnel to Casemate Jeanlain , but was forced to surrender there . The Casemate Talandier followed suit . The garrison at Maulde received orders to sabotage the position and evacuate , accomplishing this the night of 26 – 27 June . A German patrol the next day found the fort empty . The remaining blockhouses and casemates played no significant role in combat on the Escaut front as the Germans efficiently targeted gun embrasures in the relatively weak blockhouses . The Germans stripped the Escaut fortifications during the Occupation , removing weapons for re - use and salvaging the massive steel cloches for scrap . Units . The 54th Fortress Infantry Regiment spent much of 1939 and 1940 completing and extending the fortifications in the sector . First contact with the Germans was made on 17 May when two mobile companies of the 54th undertook the defense of the Escaut bridges between Valenciennes and Bouchain , holding until the 26th when they fell back towards Dunkerque . The bridges at Hergnies , Renaissance and Quiévrain were destroyed . The battalions assigned to fixed positions held until 25 June , when they too fell back to Dunkerque . The unit was evacuated during the Dunkirk evacuation to Plymouth , England . The 54th RIF returned to France as part of the French 54th Infantry Regiment of the 43rd Infantry Division in the June 1944 Invasion of Normandy . Much of the unit was captured by German forces near Falaise on 17 June 1944 . Present status . Both the Ouvrage d ' Eth and the Fort de Maulde are abandoned . The Casemate du Cimitière - du - Mont - des - Bruyères has been open to visits by the public since 2009 .