Another new technique was the use of artillery in turrets on top of the forts that could be rotated 360 degrees, an idea conceived by Belgian fortifications engineer Henri Alexis Brialmont.
The northern fort had a main armament six 6 cm pieces in armoured turrets, with eight caponier cannon for close defence.
The construction of the fortress was completed by 1902, but suffered various problems such as a lack of ventilation, heat sources and power supply.
Damp damage due to water leaking in through the mountain—a consequence of blasting with dynamite as well as the bedrock type—led to the condemnation of the southern fort as unhealthy to reside in, in 1912.
The problem was not solved until 1944 by the addition of a metal roof, 17 years after the fort had been decommissioned in December 1927, though it was still in use as a storage facility.