Replacement Gerrit Krol Bridge, Groningen

Cohesion

The Lemmer–Delfzijl main waterway, of which the Van Starkenborgh Canal forms part, is undergoing major modernisation. In order to accommodate commercial shipping, such as four-layer container ships, as well as recreational traffic, the canal must be widened to 54 metres. The bridges must also be raised. This intervention created an opportunity to upgrade the landscape. The original river Hunze, now invisible within a concrete straitjacket, could once again follow its natural course and flow towards the open landscape and the Wadden Sea.

The greatest challenge in the Gerrit Krol Bridge was to fuse all the converging demands into a functional and clear design that gives coherence to everything. A lift bridge with a span of 54 metres is an enormous structure, especially if you also want to retain the function introduced in 1993 of a bridge for cyclists and pedestrians that is always accessible. The new connection between the two different areas had to be as visually strong as the old pontoon swing bridge, allow cyclists to cross at all times, and at the same time fit into its surroundings: the edge of a residential district, opening onto a green, inhabited rural landscape.

This is expressed above all in the bridge abutments and the wide underpasses on both banks. On the city side, there is a stepped landscape, with both new places to stay and reused bricks from the old bridge. On the opposite bank, the underpass is more generous, the landing more densely planted and more ruggedly detailed with gabions. This fits well with the landscape through which the Hunze once again flows freely.

Serviceable and visible technology

The old bridge was, in every respect, a machine, with a moving weight that allowed the pontoon to drift away. The new bridge also offers a visual experience through the large wheels on the towers, which are approximately 25 metres high and as open as possible so that the ascent and descent of the bright white counterweights can be seen from every angle. The fact that, despite everything, the bridge still appears slender and simple has everything to do with hidden technology. The lift bridge itself is a deck with a minimal truss that has been subtly chamfered. The machine rooms are located underground at the foot of the lift towers, and the electromechanical operating system is so well balanced that little energy is required to open the bridge. The subtle folded lines in the surfaces of the towers, the differences in colour between the various parts of the lift bridge and the cycle bridge create a calm and clear image. They also serve a useful purpose: the multiple faces of the towers break up radar waves in order to avoid radar interference in fog. The signals for shipping are integrated into the towers to make maintenance easier and safer.

A bridge for Groningen

This new bridge, highly functional and refined in its design, was made for this one specific place. It would not make sense anywhere else. The bridge embodies what this location needs in terms of function, experience and future. The connection between city and countryside, the contemporary reference to the aesthetic of the old bridge from the industrial era, and the idiosyncratic cycle bridges on either side of the lift bridge, to which the people of Groningen have been accustomed since 1993, give the Gerrit Krol Bridge a unique character. A grand gesture that nevertheless obeys the call for functionality and simplicity, and subtly adapts itself to the landscape, its users and the memories with which they pass by every day. This is not only a description of the new bridge, but also an apt characterisation of the work of that Groningen writer, Gerrit Krol.

Gallery

Client: Rijkswaterstaat
Architect: ZJA Architects & Engineers
Landscape design: BoschSlabbers landscape architects
MIRT plan elaboration: Haskoning
Year: 2020 – ongoing
Project number: 1198