pedestrian bridges arsenaaldelft

elegant and slender  

The two pedestrian bridges are made of steel and span a distance of thirteen and sixteen meters. With their beautiful arch and slender form, the bridges fit elegantly into their historic surroundings, although they do look unmistakably modern. The arch is high enough to accommodate the canal boats that travel through Delft's city centre. Delft's historic inner city was decisive for the special landing. The columns of the bridge are completely submerged seemingly making them float above the water. A thin balustrade keeps their appearance airy.

a nod to the past  

For decades, the complex housed the Army Museum. After the departure of this museum to Soesterberg, the monumental complex was sold by the national government, based on the plan by cepezed and cepezedprojects, to Driestar. The material from which the bridges are constructed wink at the long history of defence and weaponry: the light but extremely strong Thorca is also used in the construction of helicopters. Because steel can become slippery and the bridges are quite steep a granular runner covers the bridge deck. The peninsula housing the former armoury and Army Museum used to be quite isolated, the new bridges facilitate new routes through this part of town.

ingenious design  

The bridge sections were prefabricated and lifted into place from a pontoon, with four inches of clearance on either side. To protect the monumental quays, the bridges rest on a submerged construction. This submerged structure is an ingenious, stepped system of screwed-in piles. By allowing two tubular piles to rest on three tubular piles, with a steel cotter in between, the width of the bridge deck remained small. The pile sections were welded on site, screwed into the bottom of the canal, and filled with grout.

The bridges connect directly to the quays, so raised landings or other modifications to the monumental quays were unnecessary. A steel runner serves as a barrier-free transition and covers the small rift between the bridge and the quays. This gap formed due to the combination of the tapered quay and the bridge which – in view of the structural forces – is straight. The gap contributes to the idea of a 'floating' bridge created by the hidden foundations piles.

The construction is kept out of sight as much as possible, partly by bolting from below. The balustrade is attached to the bridge deck from the underside. For maintenance and inspection, two hatches were made in the underside of the bridges. The chosen construction method not only keeps the bridges slim, but also makes them demountable.