A secret weapon: the water defence line

The idea to protect Holland with water is quite old: in the uprising against Spain in the late sixteenth century, the Dutch soldiers purposely destroyed some dikes to turn the land into swamp and hinder the opponent.

In later times the system was refined and fortified. This sytem was used only once: in 1672 when the French armies invaded.

 

In more modern times the system was taken to a further stage: a completely new line was designed. The new line was situated further to the west, so it would include the city of Utrecht in its protection. The building started in 1816 on command of the first king, William I.

 

The water line was desigend as a barrier which would prevent the enemy from crossing into the heart of the country. Through a system of locks, dams and pumps, the engeneers could inundate (put under water) the lowlands in about 40 cms of water. This was enough to make it near impossible to prevent crossing by foot or vehicle but was too little to allow easy access by boat.  Big forts were built to protect the weak parts in the line, like rivers.

 

In 1870 the line was mobilised for the first time, because of the German-French war. Many problems in the system were discovered and consecuently solved. The resulting line was 85 kms long and 3-5 kms wide and is protected by over sixty fortresses and other defensive works.

 

In its history, the line was mobilised twice more: in WW I, in which the Netherlands stayed neutral, and in WW II, when the Germans invaded. In 1940, a part of the line was inundated to stop the advance of Germany, but to no avail: planes flew right over it and bombed Rotterdam, modern warfare making the line forever useless.

 

Map of the Water line: big red blobs are towns and cities, small red dots are frots or other defences (not all are on the map), and the light blue is land which can be inundated.

Map of Fort Vechten, one of the biggest of the forts. All forts were unique and individual, no two are alike.

 

Fortress Asperen, 'bombfree tower'.

 

Fortress Honswijk, the only one to have these airbridges.

 

Aereal pic of Fort Blauwkapel. (patially demolished since 1960)

 

Hey. like your english is better.

Are you interested in discussing any of these matters in this (or the early modern) forum?

 

I find the art of war from the 1580s to about 1650 of great interest.

 

 

With a strategy like that, you would better bomb the pumps. But still, there is not much use: the areas menat for inundation were not valuable land: little inhabitation and no crops, just grassland.

 

But keep in mind that the line is no longer used. It became superfluous when planes were invented, for obvious reasons.

It remains a facinating defence idea still.