Siege of Antwerp - Fortifications

Fortifications

The "National Redoubt of Antwerp" consisted of four defensive lines:

• a principal line of resistance comprising a ring of 21 forts approximately 10 to 15 km outside the city
• a secondary line of resistance of around a dozen older forts around 5 km outside to the city
• a group of two forts and three coastal batteries defending the river Scheldt
• a small number of pre-prepared inundations

Most forts were of mid-19th century construction, but most were modernised in the years leading up to the conflict. A number of forts of the principal line of resistance were of modern reinforced concrete construction.