The following is our proposal for the Domus’ “Project Heracles” competition, an international call for ideas for an imaginary infrastructure connecting Africa and Europe. The deadline was june, 8 2011. All submissions had to be in postcard format. The image side was to contain visualisations or diagrams of the proposal; a short description, message or motivation of the entry intentions could be included on the back.
Here is a a short preface.
The injection of initiative, strength of soul and human resources from Africa will be for Europe and for the rest of the Western world an increasingly key resource. We cannot escape the future. It will be (indeed, it is) essential to build a real and functional, but also symbolic and (anti-)monumental connection between the two continents, each of which will increasingly need the other.
The original correspondence between the two philosophers Lieven De Cauter and Dieter Lesage, published in Domus few weeks ago and which formed the occasion for this competition, was in 2002. In the meantime – in fact, in recent months – a lot has happened, much to make that correspondance appear as a pleasant discussion on Two Chief World Systems. No one would have expected that decades of stagnant situation would be resolved by the same North African populations in an almost autonomous way. And that exercise of thinking intelligently started by two brilliant philosophers becomes today relevant and concrete.
So, as an Eurafrican bridge finally starts to make real sense, we tried to make a special effort to avoid Pindaric flights: the topic is much more serious than it appears, and we tried to address it seriously.
There are two ways to deal with a call like this: on the one hand, most zealous designers will produce one of the countless feasibility sketches, but we are sure that this wan’t the purpose of the competition. On the other hand some, best, will produce an idea, a provocative concept, an evocative diagram in the form of an architectural proposal, well theoretically supported.
In attempt to do something really memorable, we tried to be both conceptually impeccable and technically flawless. We hope we made it in a worthy manner…
Plus Ultra: a smart archipelago for the Gibraltar Strait.
2011. North Africa is burning. African populations have shown greater political maturity and greater connectivity than the rich West had ever imagined. Africa has taught us a lot, we advanced West. We old West. We hope that wisdom sooner or later will replace (especially in Europe) expediency and short-sighted view of the future. We believe that sharing and exchange between cultures can bring more benefits than fear and seclusion.
So. Let’s be optimistic. Let us assume that the future will be better than the present, that humanity tends to improve. Let’s take for granted that Europe and Africa in the near future will be able to establish an equal relationship, a fair exchange of knowledge and resources, each one with its own specificity, each in enhancement and respect for the other.
In this perspective, it makes sense to think about an effective and functional link between Europe and Africa. An Eurafrican Bridge crossing the Gibraltar Strait, the so-called Heracles Pillars, considered by the ancient inhabitants of the Mediterranean as the limit of their known world. But it would be reductive to think of this mythical bridge only as a place of transit for people and goods. This unique opportunity should be seized to create a space, a real place for encounter and exchange.
It must be a special monument, but as far from being a demonstration of an assumed Western technical superiority.
Heracles gets smarter
Today it is economically unsustainable and practically impossible to build a long span bridge between Europe and Africa, a 15km-span bridge with seabed reaching 800 meters in depth. And it will be impossible in the next 100 years, if materials will evolve at the current rate. Beyond pure mental speculation (or engineering companies world marketing), if we really want to build a bridge between these two continents, and if we want to build it with affordable costs and in a reasonable time, we should not do it with old mental categories.
Next centuries will no longer be marked by brute force. We think that the bridge should not be a desperate show of power, but a sustainable example of intelligence.
We look to the tribal people of Lake Tanganyika: to overcome waterways and transport their stuff from one coast to another does not carry any load on their shoulders, walking on the muddy/insidious bottom (like traditional bridge structure does), but they put them on their canoes exploiting forces that nature offers. Even the ancient Romans, almost 2000 years ago, thought of a smart connection between Calabria and Sicily across the Strait of Messina by a bridge made of boats.
In fact it will be more logical to take advantage of what nature makes available to us: physical laws that were begun to be studied thousand years ago right here in the Mediterranean, with Archimedes. Ineluctable physical forces at zero costs, like buoyancy.
Say Hello to Tension Leg Bridge
So we haven’t thought of an expensive, suspended straight line, but of a cluster of islands anchored to the seabed and functionally linked one to each other, able to take advantage of the buoyant force, winds, sun and the natural W-E currents of the Gibraltar Strait to generate energy on site at no cost.
A scalable, modular system can be implemented, or partially grown/replaced over the years, with significant advantages in terms of maintenance and investment potential.
To support our cluster of islands we implemented a system already proven in the field of advanced offshore oil platforms, known as “TLP”.
A Tension-Leg Platform is a vertically moored floating structure used last two decades for the offshore production of oil or gas, and is particularly suited for water depths greater than 300 metres (about 1000 ft) and less than 1500 meters (about 4900 ft): exactly the depths that make our case.
TLP + small bridges = TLB (“tension leg bridge”), a system with a cost-per-mile of 1/20 if compared to a long span bridge built with current technology. The system is completely independent of the depth of the seabed (or rather: the greater depth means greater stability, amplifying the pendulum stability effect of the floating system).In offshore oil industry it’s experimentally proven that even under a tsunami such systems have maximum transverse oscillations of 3 feet, which can be further reduced by special dampers.
So we think of a TLB archipelago designed according to an exagonal grid (the triangular module is form resistant and structurally very efficient) and anchored to the seabed between the coast of Africa and Europe, connected each other by “small” (750m) and affordable thick bridges, including highways, railroads, parkways, farms, buildings, a 9holes golf course (!) high enough above the sea level to permit the passage of ULCC supertankers and large cruise ships below.
These thematic islands could accommodate residential, office and leisure functions so to create a kind of offshore-city instead of a simple bridge, a new “capital of the Mediterranean”: a sort of roman viaduct reaching the height of 110m halfway, remastered with a new mixité of functions, which would become for the Mediterranean what Ponte Vecchio is to Florence, or Rialto to Venice, able to generate brand new property value and so getting paid almost for itself.
Decorative patterns distinguishing the volumes over the offshore platforms gradually change as you travel from coast to coast: from Hispanic and Portuguese motifs on the European side fading to Berber, North African and “tribal” textures on the African side.
Pillars of Hercules of our times go soberly multiethnic, far away from being frozen monuments and from the tackyness of hypertrophic Dubai ashtrays. From being the limit of the known world finally they become the meeting point of two entire worlds increasingly linked toghether.
©Spacelab Architects, june 2011
Luca Silenzi, Zoè Chantall Monterubbiano