Rumors say that whispers of forgotten soldiers echo within these walls. Welcome to Zwischenwerk IXa a relic from a bygone era. This is part of Cologne’s former outer ring of forts. It stands on the eastern bank of the Rhine. This small infantry structure was built in the late 1880s.
Zwischenwerk IXa never had a central entrance. Instead, it featured three separate entrances. These led directly to the casemates. A dry moat once encircled Zwischenwerk IXa. Today, no trace of it remains. Due to its size, the fort lacked some features. It had no Kehlgrabenstreiche or Grabenstreichen.
Much of Zwischenwerk IXa was lost during demolition in 1922. Guardhouses and protective structures disappeared. Concrete reinforcements also vanished. From March 13 to September 26 in 1922, the defense installation was leveled. The guard towers and observation points were destroyed. The concrete roof reinforcement was removed. The rampart and ditch system were also flattened.
The city of Cologne has sealed all openings for safety. Interior visits are no longer possible. Once, this site was part of the Wehrmacht’s training grounds. Later, it belonged to the Belgian forces until 1995. In 2002, Cologne acquired the area. The Westhovener Aue now serves as a retention area during Rhine floods. Since 2005, the area is open to the public. It fills a gap in Cologne’s green belt.
Zwischenwerk IXa differed from other forts. It lacked a central entrance. It had six small entrances instead. Three of them were sealed later. The infantry area had no projection for defense. The usual shoulder ditch defenses were also missing. Two guard rooms with observation snails faced the enemy. Another unique feature was the walkway. It was unusually located near the entrance. Usually, it is in the more protected rear area.
During World War II, bombed-out citizens found shelter here. They used Zwischenwerk IXa as an air raid shelter. But without concrete roof reinforcement, protection was questionable.
Zwischenwerk IXa was designed only for infantry use. The guard room ceilings were made of reinforced concrete. The fort housed about 50 men. It measured roughly 100 by 140 meters. Wall thicknesses varied. The guard room walls were up to two meters thick. Infantry room walls were one meter of brickwork. There was one meter of sand and another meter of brickwork. Standard ceiling thickness included brickwork, sand, concrete, and earth. The ditch was up to three meters deep. It featured a pointed ditch with a surrounding barrier grid.
Today, Zwischenwerk IXa stands in an open area. Access is restricted for safety. The city of Cologne has permanently closed the fort with a barred gate. Official interior tours are no longer possible. Although closed, Zwischenwerk IXa remains a monument. It reminds us of Cologne’s complex past.