To be in a borderline:
"... in the hot sun (they feed on the sun), in the shade (they feed on the shade), or in the borderline between sun and shade" - H. Michaux
El "B" is this long construction, a body, that feeds on the heritage -the continuity- of a site's treatment: THE Cartagena harbour, which is nothing but a harbour in Cartagena, borderline of the city from the sea. Everything here belongs to it, belongs to the port, any port we should say: the immaculate straightness of the pier edge (straight), the invariably calm sea (flat), the artificially horizontal plane of the dock (flat), the sky as the variable background for this plane (plane on a plane?), all based on an artifice to represent the simplest -and by virtue of its simplicity, the most natural, the most immensely artificial- plane that equates to the most natural.
The Alfonso XII dock is 1,000 metres long, exactly a kilometre, where we can assume that we are at the end. A 20 metre wide strip runs the full length, parallel to the edge, which is respected by the buildings. A very pleasant walk can be designed for the city along this strip, a daily procession following the immutable edge. In fact, this promenade is what we encourage; it is what we insert in the building, in a dimensional continuum that seems to dig out an artificial beach, but is actually a continuity of history, because the old El Batel beach was right here, on this very spot. The harbour is artificial, not the beach.
This reclaimed beach-ramp gradually submerges us below the waterline, with the pier's horizontal line as a constant reference. At this point we cease to belong to the outside world and start to belong to ourselves, ourselves in movement, ourselves strolling, working on the 210 metre scale reserved site for ourselves. We have worked on the contrast with the outer facade produced by the cut at ground level, and we continue to make use of the dictatorship of the dock, but precisely in opposition to it.
We refuse include the harbour's beautiful orthogonal monotony; we exclude the hardness of the port from the interior, and instead, we seek something that is completely the opposite: translucent, delicate, light, aquatic; something that has to do with what Luigi Nono defined as "a space for water music". Each component and detail of this project is another project in itself, but, as each project, acting in obedience to its surroundings, all belong to both a whole, not sought, but deduced, which is what shapes the character of El "B".
All the material, both aluminium and plastic, is manufactured from a single extruded section, varied in placement and colour to give the appearance of multiple pieces. These pieces are all set parallel to the pier edge to underscore the idea of horizontality and achieve an even longer rectangle than it already is, in this case extruded like a “churro” (wrinkled doughnut), only on its immediate scale: overall, it seems to be the result of an accumulation of different components, stacked neatly on the pier. The memory of a former use.
Outwardly and also inwardly, this is an extremely false complex, one set as the antagonist of the other, like people who seem to be very quiet but are actually paralyzed by the continuous movement of their central nervous system. Their antagonism is clearly evident in the coexistence of the upper and the lower floors, a perfect example of anacoluthon: there is no agreement between them. Their only connection is that both thrive on the harbour, because, we insist, the entire project thrives on the idea and the memory of a harbour; what happens here now and what used to happen here.
Cartagena has opened the El Batel Auditorium and Convention Centre, which also serves as a theatre and concert hall. The building, an ethereal structure composed of straight lines, conveys the harmony and serenity of a calm sea. Its form is reminiscent of the freight containers found in the port where the building is located. Thanks to the innovative materials used and the absence of columns, the interior spaces are open and full of natural light.
El Batel, designed by the architectural practice SelgasCano, has two distinctive auditoriums, both incorporating 6032 Flex seats by Figueras. In each case, the Flex seats were customized in accordance with the architect’s instructions to match its setting.
The interior design of the1401-seat capacity Hall A is based on an ocean theme. The seats, in blue and green tones, are arranged in asymmetrical combinations to create a sense of the sea’s movement. In contrast, Hall B evokes the warmth of the Mediterranean region: the sun, fire and the earth. The seats, in orange, red and yellow tones, blend in perfectly with their setting and contribute significantly to the overall feel of the auditorium.
Our company PT Polimer Tecnic was involved in this project developing all plastic materials and elements in polycarbonate and polymethyl methacrylate. Our expertise are new developments with polymers and innovative applications. We are process designers and manufacturers of our own materials in acrylic, polycarbonate, PET and other polymers. This knowledge allowed us to be the key partner in some projects like Hotel Puerta América, Reyno de Navarra sports hall, FEDA building, Factoria Joven de Mérida, Aquarium of Santander, etc. Today our company has expanded his area of influence with several projects on development in different countries in the world like Qatar (covering communication towers), Chile (Internal acrylic columns in commercial center), France (translucent facades), Mallorca island (transparent swimming pools), Norway (sound barriers)
Speaking about Cartagena, we entered in this project in a very curious way, after studying the project we thought that was not very clear in the definition of the different elements and we refused to apply for it without to pay a lot of attention on it. Two years later we were requested to assist one of our customers to build the facade structure in clear transparent acrylic to avoid a classical steel one. As acrylic experts on special projects we were very interested by the challenge and we prepared an offer to support the facades on 1000 width and 100mm thick acrylic columns. After our first meeting with the architect we exchanged a lot of information and we offered our knowledge to solve some of the problems that we saw in the preliminary analysis of other parts of the project. After several conversations the clear transparent structure idea was refused due to the cost was over budget but some of our recommendations related other points were accepted by the architect and we started a very close cooperation to develop his ideas in the most performant way because we are very proud to be the most innovative and technically prepared company in this field.
Our high level knowledge of materials, the long term experience in special projects (architectural and industrial) and the capacities of project development and laboratories that we have inside of our company were very helpful to develop this project because all parts of the project were completely innovative.
We started proposing the material for the external and internal skins of the facade. According the architect requirements of a double wall, and our experience, we decide to go for a double skin in PMMA (acrylic) and PC (polycarbonate). The acrylic external skin has a long term ageing resistance that PC can not guarantee but this secondary intern skin gives the impact and fire resistance to the wall that are necessary.
The external wall of 10 meters height is made with 5200mm long and 250mm width profiles in clear PMMA resin with four fluorescent 1mm lines. The initial design was modified according the technical possibilities and the technical requirements from the architect. Two special dies were manufactured for the V shape profile production with two different angles and teeth structure on the backside to have different light refraction angle depending of the light incidence and the moment of the day. Profile was defined in 6mm thickness to pass the fire tests on the PC profiles.
Another important question was to develop the fluorescent colours that were requested by the architect. Most part of the polymer suppliers were offering masterbatch resins with a colour life resistance expectation of 3 months. Here our 50 years experience manufacturing PMMA sheets in a sister company allowed us to guarantee fluorescent pigments with long term outdoor resistance. This pigments were mixed with the PC resin to produce the 30.000 meters of 50mm special pipe profiles that were installed on the top of both facades.
The selection of the polymer resins employed in the different parts of the project was also a Polimer Tecnic decision. Quality and properties of each material were checked by our technical team in order to guarantee that all elements to manufacture has to fulfill the requested properties. The selected partners were Evonik and Sabic depending of the material. Other companies like Arla Plast were also cooperating with Polimer Tecnic to manufacture specific parts of the project. Installation was developped for the team of our long term partner Aislamientos ATA that developped a really nice work.
Fixation system was also designed by Polimer Tecnic with an innovative clip system. No screws are present in this facade, the profiles are supported by stainless steel minimalist supports that have same thickness than the metallic support structure, 30mm only. This was a big challenge in order to reduce the steel structure to a very thin vertical structure.
Inside the main auditorium we find same profiles in light blue colour with natural light entering from the top and reflected light on the bottom side due to special plastic mirrors covering the concrete walls to avoid too dark areas. When you enter in the main room the visitor feels that never before he was in a similar place and he is attracted by the light of this space.
We can find also Vitroflex-PC opal 30% translucent sheets in the kitchen and Vitroflex® PMMA cast acrylic blocks in opal translucent white 30mm in the outdoor tables in the restaurant area. These tables were specially designed with a high resistance polymer that can maintain his translucent glossy white for year and year without any discoloration. Tables are practically indestructible but if damaged by some hard element can be easily repaired in few minutes by our specialists.
Small things were also considered element by element, as example, ventilation flows also throught some perforated polycarbonate sheets distributed along the corridors. You can see it in one of the photos attached.
Stairs balustrade was also designed with a material that has much higher transparency and impact resistance than glass, long life and warm touch. The selected material that you can see in the attached stairs photo was Vitroflex® 20mm clear blocks fixed only by the bottom part of the pannels, to avoid any interference to the clear vision throught. On top only a thin steelbar was permitted to avoid fears.
I have to say that I was involved personally on this project and it was a pleasure to work toghether to Mr. José Selgas and the other technical people. Never before I saw a so innovative building with all the team working toghether in order to reach the best results and knowing that a lot of the materials were specially designed and not tested before. I’m really proud to have been there.