Kruunusillat bridge competition winner announced

The winner has been announced in Helsinki's Kruunusillat light rail bridge design contest: WSP Finland / Knight Architects. There's a video of the winning design on YouTube.

Second prizes have been awarded to entries from Arup  / Amanda Levete Architects, and Pontek Consulting Engineers.

The minutes of the Jury make interesting reading, and readers may also want to look back at my three-part review of the competition entries: 1, 2, 3.

When I get a few spare moments, I'll post some more detailed comments.

Kruunusillat bridge design competition: the entries (Part 3)

This is the last of three parts, concluding the entries to the Kruunusillat bridge design competition ... You can find more details on all the entries online, and there's a set of all the videos on YouTube.

Gemma Regalis

Most of the entries seem to have taken the view that the bridge should not compete visually with the relatively low-lying Helsinki skyline. This is the only one to buck the trend, with a single tall cable-stayed mast at its centre. The secondary spans are prestressed concrete on Y-shaped supports. The walkway is on one side of the bridge only, which I think is the best choice.

Recreatio Maritimus

This bridge is a sequence of very different experiences, with different structural forms to suit. At one end, there's a garden walk, with a tree-lined promenade carried on an arch bridge, and at the other the tramway and walkway are separated by a single central truss, supporting canopies on either side. This separation of tramway and walkway seems sensible, but it's far from clear why users would only want shelter at one end of the crossing and be exposed to the elements along the remainder. This design would also presumably require a substantial box girder below deck level to provide torsional stiffness, which detracts from the otherwise slender lines a truss can offer. On some of the shorter spans, an undulating spine girder provides the same separating function.

Oculus

From an engineering perspective, I find this last entry by far the least convincing. The obvious question is why they went for a suspension bridge, one with twin 550m spans - there seems nothing about the site to suggest that multiple foundations in the water will be an issue for navigation or construction. The resulting design attempts to be slender, but requires additional stay cables and a massive under-deck truss to provide the necessary stiffness. Design of light rail bridges is governed by stiffness, and a suspension bridge is fundamentally ill-suited to satisfying this criterion. The concept reduces the number of bridge bearings and joints to a minimum, but at what cost?

Kruunusillat bridge design competition: the entries (Part 2)

Okay, here's the second of three parts, continuing a quick run through the entries to this Finnish bridge design competition ... You can find more details on all the entries online, and there's a set of all the videos on YouTube. The first part is here.

Filum Lucis

I can see this design being unpopular with many of the people who tend to comment on architecture blogs and websites, but I like it. The bridge is a simple post-tensioned concrete box girder, cast in-situ, and intended to offer the most minimal line possible across the site, something which seems highly admirable when set against more attention-grabbing schemes.

Unda Arctica

This is one of my favourite designs, with a very elegant series of "undulating" arches, the arches above the bridge deck separated by reverse arches below the deck. Although that's visually attractive, it isn't structurally rational, with the reverse arches subjected to much higher bending loads than is desirable. Pedestrians and light rail are each allocated to once side of the deck, avoiding the separation of pedestrians into two streams that some of the other designs require.

Occursus

In the previous post, I featured one design where the pedestrians and light rail vehicles were both tucked away inside a sheltering truss structure; and one where the light rail was sheltered inside the truss but the pedestrians exposed to the weather on an upper deck. Occursus offers a hybrid of these solutions, with the light rail on the steel truss's top deck, but pedestrians free to use either level, possibly according to the weather. I can't help thinking that most of these designs pay too much attention to the pedestrian users: this is a bridge over 2km long, which to me seems an excessively long, narrow corridor for walkers, although it's very suitable for cyclists. Won't most bridge users simply take the tram?

Septem Fratres

At first sight, this entry is very similar to Nexu, which I covered in the previous post. This one has seven central cable-stayed towers with 130m spans, while Nexu had six towers and 160m spans. The text for Septem Fratres describes it as an "extradosed" rather than "cable-stayed" bridge, which just means that the towers are of lower height and the cables at a shallower angle - it's a halfway house between cable-stayed and post-tensioned box girder bridge. The lower profile is one attraction, but I also prefer that on this option the main pedestrian route is all on one side of the bridge.

Kruunusillat bridge design competition: the entries (Part 1)

I thought I'd do a fairly quick run-through of the 11 entries to Helsinki's bridge design competition. You can find them all online, with more images than I'll show here, and there's a set of all the videos on YouTube.

The entries are submitted and judged anonymously, and have all been given odd Latin names for ease of identification. There was a list of ten entrants in my previous post, I don't know why there are eleven entries on display. Here's that list again:

• WSP Finland / Knight Architects
• Arup / UNStudio
• Carlos Fernández Casado
• Pontek Oy
• Knippers Helbig / Zwarts and Jansma
• Apia XXI / Batlle and Roig
• Schüssler-Plan Ingenieurgesellschaft / Dietmar Feichtinger Architectes
• Setec TPI / RFR
• Roughan O'Donovan / Michel Virlogeux / Dumetier Design
• Arup / Amanda Levete Architects

Here are the first four designs, I'll continue with others in later posts:

Ventus

With its series of repeated cantilever / stayed steel modules, this bridge reminds me of Riccardo Morandi's Lake Maracaibo bridge. That concept belongs to a long-dead period of stayed-bridge design, overtaken by methods involving larger cable arrays which are cheaper to erect. The position of the steel stays doesn't appear structurally rational - the obvious point to connect to the deck is at the third-span points, not near the centre. Visually, it is highly distinctive, and not so tall as to be overbearing.

Nexu

The Nexu design is the more conventional version of the first proposal, with a single row of pylons in the centre of the deck and a conventional central band of cable-stays carrying the deck. Its sense of discretion appeals to me, it appears to be trying to fit into the landscape rather than distract from it. Viewing the video, you can see two cycle/footways, one on each side of the central tramway. I don't think this is ideal for such a long bridge - users travelling on foot should all be able to mingle in one walkway area.

Debet Semper Plus Esse Virium In Vectores Quam In Onere

I think this is easily the most interesting entry, a hugely elongated covered bridge intended to provide shelter to users throughout the year. Pedestrians walk on a central raised platform, with tram tracks either side. A diamond-faceted shell provides the enclosure. It's hard to decide whether the lack of visibility and exposure to the landscape is a price worth paying for the provision of shelter. I'm unclear why the shelter needs to cover the tram tracks - it would be less expensive, and easier to maintain, if only the central spine were covered, and the tramway left exposed to the elements.

Hyperborea

Over much of its length, this design separates the tramway from pedestrians by locating the walkway on the roof of the main truss girders. This may have advantages in terms of providing views, but as with the previous design, it leads to a very deep structure overall. Unlike the previous design, the trams are sheltered and the pedestrians are not, which may seem perverse in poor weather. The truss girders are not steel, but in ultra-high performance concrete, prestressed to give it the necessary tensile strength (it is otherwise a material very similar to cast iron in performance). This is innovative, but high-risk - I don't believe UHPC has been used in this manner or scale before, and while the concrete will be durable, there are a large number of very short prestressed members, which is not efficient to assemble, and construction may be expensive, as some forms of UHPC require steam-curing to achieve their best properties.

Kruunusillat bridge design contest entries revealed

The eleven entries to Helsinki's Kruunusillat light-rail bridge design competition have been made public. They are being exhibited locally, and can also be found on the internet.

If I get time in the next few days, I'll post some of my own thoughts, but feel free to comment here.

Kruunusillat contest to restart

After a delay of a year, Helsinki's Kruunusillat bridge design competition is finally to move forward.

Following submission and evaluation of prequalifications, the contest ground to a halt last year when one entrant, Leonhardt, Andrä und Partner, decided to challenge the evaluations in court. Now, the Finnish commercial court has rejected that challenge, and the scheme can again move ahead. No date has yet been set for the restart, nor have the chosen ten competitors been officially announced.

However, I've seen the prequalification evaluation report, and here are the ten teams I expect to be taking part in this competition:

• WSP Finland / Knight Architects
• Arup / UNStudio
• Carlos Fernández Casado
• Pontek Oy
• Knippers Helbig / Zwarts and Jansma
• Apia XXI / Batlle and Roig
• Schüssler-Plan Ingenieurgesellschaft / Dietmar Feichtinger Architectes
• Setec TPI / RFR
• Roughan O'Donovan / Michel Virlogeux / Dumetier Design
• Arup / Amanda Levete Architects

There are some well-known names in there, as well as several that were previously unknown to me. I would say they are all quite capable of producing a fine design for a 1km long light rail viaduct, which is the central substance of the design competition.

However, there were a number of very big names who failed in prequalifying. As well as Leonhardt, these include the likes of Zaha Hadid Architects, Gehry Partners, Studio Daniel Libeskind, Ramboll, Rosales & Partners, Marc Mimram, Aecom, Flint and Neill, Schlaich Bergermann und Partner, Ney & Partners, Buro Happold, and many more. Several of these are clearly as competent as the firms which did prequalify, if not considerably more so in some cases. It's also clear that this was a very attractive project for some major designers, no doubt helped by the payments available to competitors, which are generous by comparison with many other bridge design competitions.

The evaluation process was based almost entirely on participants' prior experience of projects similar to the Kruunusillat scheme. That would seem to offer little scope for the ambitious and talented, but if a client judges that a safe pair of hands is what's important, then that is their choice.

What was notably more peculiar was their insistence that the projects submitted to demonstrate experience had to be on the personal CV of the lead structural and architectural designers. I find that quite bizarre given the way that most designers operate as teams. Will the success or failure of Kruunusillat's chosen design really depend on the prior experience of figureheads? I find that absurd.

If this were not bad enough, the actual prequalification evaluation process looks quite comical when seen from outside. One of the failed entrants, a structural designer respected worldwide for their landmark bridge expertise, was judged as follows (scoring a miserly 65 marks out of a possible 200 for structural engineering):

"Structural designer who has solved the problems conventionally. The overall structural engineering impression of the references is ordinary. However, the references lack broad projects with overall responsibility for planning."

Two very well-known, very large international consulting engineers, both with an excellent track record in bridge design, secured only 20 marks out of 200 in the same category.

Another entrant, a world-famous architect, scored 80 out of a possible 100 for bridge aesthetics, despite securing these comments:

"Very few bridges or infrastructure projects presented. It is hard to judge if the applicant would have anything to offer in the bridge design even if the building projects are interesting with highly expressive forms. This kind of design approach would probably not suit at all to bridge design where special care has to be given to integrate the structures to the aesthetic design. Moreover the applicant's contrasting attitude to the surroundings in the very valuable competition area probably wouldn't lead up to good results. Why did not the applicant join forces with somebody else having the required bridge references?"

I could easily offer many similar examples here, but you get the point. The evaluation was, at best, highly subjective, and at worst, crassly incompetent. I am sure those taking part will provide some excellent designs, but there is more than one consultant who should feel aggrieved at how the scheme's design procurement has been handled so far.

Leonhardt's submission to the Finnish court raised much the same issues. They contended that the numerical marking and verbal assessment were inconsistent; that the marking for other contestants was so inconsistent as to indicate a lack of objectivity; and that the criterion eventually used for scoring had not been properly set out in advance in the City of Helsinki's invitation to prequalify. The court's decision can be found online.

Kruunusillat contest suspended

I see from the BD&E website that the Kruunusillat Bridge Design Competition, for a new light rail link in Finland, has ground to a halt. Apparently, an appeal by one of the teams has resulted in Finland's Market Court suspending the contest. A delay of two to twelve months is now forecast. I previously discussed the competition here.

52 teams had submitted prequalification entries. Seven of those had been disqualified for various reasons, and the remaining teams had been notified of how their entry had been scored, with the expectation that a shortlist of ten competitors would be announced at the end of September to move forward to the next stage.

Having seen the detailed judging panel comments and scoring for all the entrants, I was all set to post some comments here on who had been selected, and who had been left out. There were some surprising scores, to say the least, with some very experienced and capable entrants ranked well below less well-known teams. Some teams made multiple entries, and I'm aware of one engineering firm who were rated with a score of 200 for their engineering capability in one entry, but only 20 in another.

Many of the comments from the judges seemed poorly matched to the scores actually given - one very well known architect received a high score for their aesthetic capability despite being criticised for their insensitivity to bridge structures in the accompanying text.

The way the entries were judged seemed to favour the capabilities of individuals with a well-stacked CV over the capabilities of a broader team. That was always a bizarre approach to take.

I don't know who has scuppered the whole process but would have thought that some of the disqualified entrants would have been very surprised to find themselves in that position.

It will be very interesting to see what further news emerges. I imagine there are many disgruntled contestants beyond the one firm which went to the court. Would any of my readers care to click the comment button to provide further feedback?

Helsinki Kruunusillat bridge design competition announced

An international competition has been announced to design new pedestrian, cyclist and tram bridges in Helsinki, connecting a new residential area to the city centre. The bridges, termed Kruunusillat ("crown bridges") fall within a designated heritage area, and are being partly promoted under the auspices of Helsinki's role as World Design Capital for 2012.

The budget for construction is €86m, and these are not small structures, but crossing major waterways. The longest bridge will be over 1km long, rising to 20m above water level.

Prequalification submissions are requested from teams of bridge engineers, architects and supporting specialists by 3rd August. Full details of the programme, jury and how to apply are available on the competition website. More information can be found at the Official Journal of the European Union.

Between 5 and 10 design teams will be shortlisted, and each one is to be paid €50,000 for their efforts (plus expenses towards producing a scale model, and some limited travel expenses). If the contest moves into a second phase, a further €25,000 becomes payable, and there is the prospect of a design contract for the winner. This is pretty generous, certainly when compared to UK standards, although the competition submission requirements are very detailed, including production of numerous drawings, photo visualisations, reports and animations as well as the scale model.

I expect they will attract some very high-powered entrants, although the nature of the site is that designs will tend towards the elegant rather than the spectacular.

Bridges news roundup

Time for a quick interlude before moving on to day two of the Swiss bridges tour. Just three quick links to bridge stories I've spotted recently:

10 Most Amazing Bridges

Proposal for new 900m bridge costing EUR 125m in Helsinki
Architectural competition to be held next year for bridge carrying trams and light traffic

Steven Holl wins Copenhagen gateway competition
Cable-stayed footbridges cantilever in twin-tower "handshake" (pictured below)