Habitat opportunities in harbours – Port of Rotterdam

Construction

Before the actual construction, the conceptual designs from the previous phase were further detailed. After the detailed design had been finalized, the polehulas and pontoonhulas were placed at the dedicated locations. 

Prototype design
Installation of polehulas

Detailed design and construction

The bare polehulas and pontoonhulas were placed in the Scheurhaven and the Pistoolhaven in March 2009. In the Scheurhaven, polehulas were placed around 5 wooden and 2 steel poles and in the Pistoolhaven the polehulas were placed around 3 steel poles. At the wooden pole, one polehula was placed above mean low water (MLW). Below MLW, three polehulas were added with an overlap of 10 cm. The aim of this variation is to determine the optimum position of the polehulas with respect to the water level. At the steel poles, only one polehula is placed below MLW around each pole. 
Pontoonhulas type I, with a size of 85 x 230 cm, and a varying rope density of 40, 80 and 168 ropes were used in the Pistoolhaven. In the Scheurhaven two pontoonhulas type I, with a size of 160 x 200 cm and a fixed number of ropes per pontoonhula of 208, were used. Moreover, two pontoonhulas type II were used there, with an area of 160 x 200 cm and a fixed rope density of 208 ropes per pontoonhula.