10.08.2018, 14:57 Uhr

Structural Awards 2018: Queensferry Crossing and Tamina Canyon Crossing shortlisted

The Queensferry Crossing and the Tamina Canyon Crossing are both shortlisted in the Category “Award for Vehicle Bridges”.

Queensferry Crossing

The Queensferry Crossing is the centrepiece for the Forth Replacement Crossing Project, Scotland’s largest infrastructure project for a generation. The new bridge was delivered at a cost 65% below the original budget. It is delivering extensive benefits to users and communities, whilst safeguarding vital transport connections.

Judge’s comment:

This is an extraordinary bridge by almost any measure. The scale of the structure is in itself impressive, but what sets it apart from other major long span bridges in the opinion of the judges, is the unique way in which the engineers have dealt with the particular problem of unbalanced loads on a three-tower cable stayed bridge. The crossing stays at the centre of the two main spans is a unique feature of this design, and by this simple expedient the designers have managed to maximise the slenderness of the elements and achieve substantial savings in the costs of the foundations and the superstructure.
The judges were impressed by the elegance of the solution, which manages to achieve a degree of slenderness and lightness in spite of its huge scale. In addition, the selection of such an innovative cable stayed solution to stand alongside its historic neighbours to form a spectacular trio of iconic bridges across the Forth Estuary, each representing engineering characteristics typical of its time, is considered particularly noteworthy.
Many organisations have been involved in the conception, evolution, development and delivery of this complex project, and the judges considered it a good showcase for what is involved in the planning, design and construction of such a major long span bridge.

Photo: Transport Scotland

Tamina Canyon Crossing

The bridge crosses the Tamina canyon 200 m above the gorge. The arch and the superstructure create a continuous prestressed girder mainly forming the structural system. The 417 m long superstructure is connected monolithically to the arch by inclined columns; the total length of the structure is 473 m with abutments included.

Judge’s comment:

This is undoubtedly an outstanding engineering solution, and the judges were impressed by the elegance, clarity and economy of the design. The judges noted the efficiency of the structural system, as well as the beautiful way that the design integrates with its spectacular surroundings. This is a concrete arch design in the best traditions of Christian Menn and Robert Maillart, and the engineers have produced a world class and graceful design.
The judges liked the way that the open spandrel prop supports are inclined in a radial fan arrangement, and the high degree of transparency that has been achieved, with an attractive rhythm for the spans of the deck girder. This transparency is accentuated by the slenderness of the thin inclined props which is achieved by the use of meticulously detailed concrete hinges.
The two end props, which spring from the ends of the arch, imposing both physical and visual weight at these points to good effect, work as part of an integral framing system with the slightly deeper end spans of the girder. These spans can therefore be longer, thus avoiding the need for additional foundations at the sensitive upper slopes of the valley. So the bridge stands on just four foundations, reducing construction uncertainty and maximising the economy of the scheme.

Photo: Bastian Kratzke

The Structural Awards are the world's foremost celebration of structural engineers as innovative, creative design professionals and the guardians of public safety and showcase the world’s most cutting edge engineering achievements.
Winners will be announced on Friday 16 November at The Brewery, London.