Closure decision
Statistically, the barrier will be closed once every 2.5 years on average. The closure decision is taken by an integral computer system, known as the Decision and Support System (BOS), which also decides on the closure of the New Waterway Storm Surge Barrier. If the barrier needs to be closed, shipping can use the Hartel Lock, which has been modified to make this possible.The movement of the gates is checked every 14 days by sliding them up and down a few centimetres. This does not interfere with shipping in any way.