Hoek von Holland 挡潮闸
The BMK Barrier consists of two hollow semi-circular gates attached by means of steel arms to a pivotal point on both banks. One of the advantages of the BMK design in relation to the other designs is that of ease of maintenance, as the doors are positioned dry in and at the abutements during normal conditions.
详情参见http://www.keringhuis.nl/engels/home_noflash.html
