vneerland wrote:Geweldig.
Jan, would you care to tell us how a lock (sluis) works! That is a concept, totally foreign to many over here.
Sure Judith, I will try.
Some of you may have travelled to The Netherlands and did so by airplane, landing on Schiphol/Amsterdam Airport. But I think none of you have even considered the idea that by doing so you would find yourselves 4 meters below sealavel after landing. And yet this is the exact situation, as it is for large parts of our country (more or less than those 4 mtrs.) We are being protected from the sea by sand dunes ans sea dykes. These maps might give you an idea of how the situation would be whitout them:
And a part of a sea dyke and the protected land behind it:
As you can see most of our country wouldn't exist. In fact the areas that are protected from the sealevel are the most inhabeted ones with millions of peolpe living there and having the major part of our industry is located right there.
But there are also differences in waterlevel throughout the country and a lot of waterways such as rivers and (manmade) canals. To make sure ships can travel from one part of the country to another we need an ingenious system of waterways abnd waterworks such as locks. How they function is in fact both simple as brilliant:
you make two dams in a canal which are in fact two doors that can open and close to enable ships to go in. Than you pump the water in or out depending on the waterlevel at the diretion the ship is traveling. in the early times there where relatively small doors in the lock doors themselves which could be opened by hand to let the water inside the lock in or out.
An old lock:

And a more recent one (the ship inside belonged to my dad btw):

Our coast line has changed a lot over the centuries and the part we live in the first dykes where being made by monks in the twelved and thirteenth century.
The land behind these old dykes that could be reached with low tide was very fertile and therefore being used for agricultar which ment the people who lived behind these dykes had to be able to close the road through the dyke when the tide came in. They used wooden beams to do so which where kept on top of the dykes. Some of them can still be seen as shown in this photo close to our town:
