The new Danube bridge of Budapest

For decades, there has been a demand to create a new ringroad, bypassing the city center from the south and connecting Csepel Island with the rest of the city. The integration of this bypass into the existing road network is also highly important. The route was largely designated, the junctions of the road network were defined taking into account the expected traffic. On this route there is a few hundred meter long section over the Danube, which is well defined in terms of traffic, but the type of bridge has not yet been decided. To put it differently we have the cart and we are looking for the horse.

On behalf of the Government, KKBK (Centre of Key Government Investments Nonprofit Private Limited Company), as the tendering authority, announced an invited, pre-qualified, international bridge design competition in the summer of 2017 (https://newdanubebridge.com/en#/timeline ). There has been no example of such an event for the last hundred years, with the last one being held in 1894, when a joint tender for the Eskü and Fővám square bridges (now Elisabeth Bridge and Liberty Bridge) was announced. At that time, out of the 74 valid applications only 15 were Hungarian. For the current design competition, the tendering authority expected 17 applicants, 11 of which were foreign and 6 Hungarian. The authority wanted to see an iconic and unique bridge by international standards. The authority was wise enough not to impose any specific restrictions concerning the bridge structure. However, there were a number of criteria that had to be taken into account. Among other things, such condition was that the Budafoki út junction must be two-leveled. Stipulations like this were firmly established and were preceded by professional design work.

The jury had 21 members from all walks of life including for example opera singer, politicians and engineers (https://newdanubebridge.com/en#/jury ). Their work was also assisted by a committee of experts. The announcement of the results took place in March 2018. The winning entry was a cable-stayed bridge with two pylons built by the world-renowned architectural firm UNStudio and the also famous engineering company Buro Happold (https://www.unstudio.com/en/page/11740/new-budapest-bridge, https://www.burohappold.com/projects/new-danube-bridge/). The vast majority of the jurors could judge the entry solely on the basis of aesthetic considerations, while the task of the expert committee would have been to weed out traffic, structural and static errors. They may have tried to do so; however, they obviously failed.

The result was surprising to me both technically and aesthetically. Of the 17 applicants, two had planned a one-level junction on Budafoki út. That is, they clearly ignored one of the “criteria that had to be taken into account”. The significantly larger space requirements of the one-level junction necessitate the demolition of the surrounding buildings and result in an oversized junction, but the most serious consequence is that the adjacent transport junctions also need to be redesigned. However, the new junctions will not be able to serve the changed traffic conditions with the same efficiency. We put the cart before the horse. And the new “cart” is a wee bit undersized.

A render of the winning entry (https://ujdunahid.hu/galeria/).

Another professional mistake was that despite the skewed alignment of the crossing relative to the river, the riverbed piers were perpendicular to the longitudinal axis of the bridge and not parallel with the current line of the river. There was only one applicant that made this huge mistake. As it happens, this is the applicant who was finally awarded the contract. Their design is a weak reminiscence of one of the most beautiful bridges in the world, the Erasmus Bridge in the city of Rotterdam, which was also designed by UNStudio in collaboration with the Gemeentwerken Rotterdam. Perhaps they forgot about the flow of water because the water level is constant in Rotterdam, so there is no strong drift, nor 7-8 m water level fluctuations, as in Budapest. I think, - apart from a couple of practicing bridge designers who are also committed to bridge aesthetics - just a few people see the consequences of tilting the river piers into current. Everyone seems to have been mesmerized by the image they saw in the original visuals and they don’t realize how unacceptable the new, distorted pylon shapes will be. The pictures recently posted on ujdunahid.hu also cover up this mistake. Too bad that this oversight will be visible to everyone walking along the river for the next 100 or so years to come. This distorted pylon is a capital aesthetic blunder.

The new, distorted pylon shape (https://ujdunahid.hu/galeria/).

But let’s get back to the original bridge. Ben van Berkel's Erasmus Bridge, inaugurated in 1996, is an iconic symbol of Rotterdam. The design of the backstayed asymmetric cable-stayed bridge with a backward-leaning inclined pylon is really special. The cranked pylon creates tension in the viewer, but it also reflects the serenity and elegance of symmetrical bridges. Uniquely, the thicker pylon stems continue in horizontal edge beams of similar thickness in the backspan. In front view, the two pylon stems rest on each other, forming an inverted Y shape. The bridge has two tramways and a 2x2 traffic lanes. The bridge deck is hung by relatively densely arranged cables, so the structural depth of the deck can remain thin, creating a pleasant contrast between the slender bridge deck and the cranked pylon. Make no mistake, cranked pylons are statically unfavorable, so due to the huge bending moment that arises at the point where the upper sections of the pylons turn upward, it is necessary to reinforce the pylon. Not surprisingly, 99% of pylons are straight, but at least without cranked parts.

The elegant pylon shape of the Erasmusbrug (https://www.unstudio.com/en/page/12091/erasmus-bridge ).

During his early career, Ben van Berkel worked with Calatrava and was probably so inspired by the Alamillo Bridge in Seville (https://calatrava.com/projects/alamillo-bridge-cartuja-viaduct-seville.html ), which only existed on paper at the time, that he had already submitted plans for a very similar counter-balanced cable-stayed bridge in Rotterdam under his own name. It was a little bit longer, a little bit taller than the bridge of Calatrava, but the design was structurally and statically inadequate. Firstly, it was reduced in size, secondly the backstay anchorage was applied, thirdly the cable arrangement was modified and finally the straight reinforced concrete pylon was replaced by a cranked steel pylon. This way, another iconic bridge was created, which fortunately no longer resembles the bridge of the Spanish architect. Thanks to its unique pylon shape, the bridge was a great success.

Sideview of the pylon and the horizontal beam (https://www.unstudio.com/en/page/12091/erasmus-bridge).

Thus, the winning entry is the weak reminiscence of this bridge. The bridge has the same deck width at nearly the same span, but in this case it applies two pylons rather that a single one. As a result, the proportions are distorted. The proportions of the original bridge are perfect, both in length and thickness, but in this case the position of the bending point is shifted and the vertical upper part of the pylon becomes shorter. The pylons of the originally inverted Y shape pylon no longer touch and strange cross struts are wedged between the pylon stems. The horizontal beam will be disproportionately long relative to the height of the pylon and will be obtrusively thick. All the proportions that were exemplary on the original bridge became completely flawed here.

The proportions of the New Danube bridge and the Erasmusbrug (https://www.vighattila.hu/letoltes/he/hidak_esztetikaja_2020_2ea.pdf, page 21).

Another unsightly feature is the pier-turning, which the designer solved by leaving the upper pylon section intact while distorting the lower part. Distorted pylon shapes will make the pylons look as if they were deformed by the load. The sight of distorted pylons ruins the whole composition. This bridge will create tension in the viewer as well, but not the kind that the Erasmus bridge creates.

The original, symmetrical pylon shape and the riverbed piers that are perpendicular to the longitudinal axis of the bridge (https://www.dezeen.com/2018/05/09/unstudio-budapest-bridge-danube-architecture-news/).

The new, distorted pylon shape and the pier-turning (https://ujdunahid.hu/galeria/).

It is clear that the architect refuses to restart working on the whole design from scratch, despite the fact that the geometry has fundamentally changed. He rather tries to fix up the structure. He does this because he has no other option, really. Nor is it in the tendering authority’s interest to restart the process because it would result in a loss of time and prestige.

How could this have been avoided? Is this bridge distorted or not? How could the mistakes be corrected? Why were not the entries that did not fulfil the requirements excluded from the competition? Many questions remain. It could only have been avoided if the committee of experts had been aware of the aesthetic consequences and had not examined the structure from a statical point of view only. The truly outstanding visuals of the entry showed a very calm, clean appearance of symmetrical pylons from the sideview. And this entry won, even though the design was unfeasible in this form. Everyone fell in love with a visual. If we look at the latest visuals now, we can already feel some difference, but the problem is still not conspicuous enough for the laymen to notice. In sideview, the pylon stems always block the view of one another so no distortion is felt when one is looking at the pictures. The close-ups reveal a unique perspective typical of wide-angle lenses, which distorts everything, so the flaws are hard to spot here either. There may be three viewpoints from which no distortion can be perceived, but in reality, the bridge will be seen by citizens from significantly more points of view. The mistake cannot be set right, only complete redesign would help. And the answer to the last question was that they could have done it, but the intention was different. The process of jurying also has a special dynamic on its own, but that deserves another post ...

Ian Firth, a renowned English bridge engineer - who is just as committed to bridge aesthetics - concluded one of his lectures: “Nobody is going to remember the cost. Nobody will remember whether it overran a few months, but if it is ugly or just dull, it will always be ugly or dull.”

Bridge aesthetics is certainly a subjective topic and probably many will dispute what I write here. Maybe they think that my dissatisfaction is nothing but sour grapes, because - as one the applicants of the design contest - my design was turned down. Perhaps a few will think that as the designer of the adjacent bridge, I am trying to score some points by criticizing the design of this bridge. Quite the opposite is true; I couldn’t be happier if the new Danube bridge would be one of the most beautiful structures in the world, in every aspect.