In early times ramparts and moats was very much the same. Shaped as the blade of a saw with its teeth pointing towards the enemy. (In french Trassé creamillet) This made it possible to fire in an angle of maximum 90 degrees, and prevented blind angles.
The overall purspose was to to be able to fire at the enemy from maximun range, moving the fire at he moved forward, even if he started to climb the ramparts.
Sommerfeldt also placed artillery in batteries along til defence line, that was able to fire directly at the enemy in long range “the old fashion way.”
The guns were placed in batteries (4-12 pcs:) along the 14 kilometres of enceinte.
The main ide was based on, that the enemy efter having forced the open terrain in front of the defence line under fire from heavy 9, 12 and 15 cm artillery, machuineguns and infantry-rifles should pass the waterline, ramparts and the caponieres.
The most critical point for the enemy would be, when he passing the about 6 feet deep moat, was taken under fire from a 7,5 cm rapid firing canon and two 8 mm machineguns (2 barrel mitralleuse) – from bunkers (caponiers) in the flank. These was supported from the ramparts by infantry and machineguns. This fire from the flank caponieres was directed towards the back og the next caponiere in
the line, so no blind angles would appear.
Known blind angles and crossings in the chanal, was covered cy little bunkers with machineguns in the rampage.
There was about 350 feet between the caponieres.