The expanding of the Tömmerup Stronghold across the island of Amager was initiated in 1915.
It streched 7 kilometres and was, until the building of the Sydamager stronghold in
1916, the main battle line.
If the stronghold was overrun or destroyed, the Christianshavns Ramparts should be the safety position.
The Tömmerup Stronghold was divided into both a melee line and a distance line. The main line consisted of 6 batteries and the remote combat line consisted of 4 batteries.
The position consisted of a large number of trenches and field fortified positions, surrounded by barbed wire belts.
After the establishment of the Sydamager stromnghold as a new main battle line in 1916, the Tømmerup position
lost its primary significance and it became now safety position for the Sydamager stronghold.
The stronghold was abolished together with the Sydamager position in 1919.