county Regelbau 51a near Oberleuken (at least 2 units) Regelbau 501 in Sinz (2 units) Regelbau 502 near Oberleuken Regelbau 506 in Besseringen Regelbau 509c...

round protection. All accommodation bunkers produced using the standard Regelbau system were protected against gas attack with air tight doors, ventilation...

coordinates were given to the casemates by the fire control post located in a regelbau S100 bunker along the shoreline at Cran-aux-Oeufs, 1,200 m (3,900 ft) north...