Architecture
Between past and future
Zollhafen’s energy center
Between past and future
Prof. Günter Zamp Kelp
Thanks to the vision and the generosity of the decision-makers at Stadtwerke Mainz AG the first building to be completed at Zollhafen, the former customs port, is dedicated to art. In its function as the entrance to the Kunsthalle, the “Leaning Tower of Mainz” represents an emblematic link between the everyday urban world outside and the world of art inside, marking as it does the transition between the two through its own independent appearance. Like all the rooms in the tower angled at 7°, the foyer is a room perceived as a three-dimensional parallelogram. It reaches a height of 7 m thus corresponding to one third of the total height of the tower, namely 21 m.
From here all the rooms intended for the public can be reached. Works of art need rooms in which they can unfold their potential. At Kunsthalle Mainz there are exhibition rooms with varying spatial qualities available. A large percentage of this exhibition space is located in the monument-protected old building. The rooms available differ in size and height offering a wide variety of possibilities for staging art.
Since these rooms manage, to a large extent, without daylight artificial light can be used to achieve every lighting situation between “white box” and “black box”. The reason behind the wide range of lighting techniques possible is a membrane ceiling divided up into large fields, backlit and dimmable, which can be supported by spotlights that can be positioned flexibly. One great challenge for the exhibiting artists will be in the old building: a former transformer room some 12 m in height in the historical cupola tower. Visitors can only look into this room from a small interior balcony. Its vertical quality stands in contrast to the warehouse-like character of the large exhibition areas in the direct vicinity.
In particular, the fact that the Kunsthalle’s identity is characterized not only by its historical building elements but also by the new building, “The Leaning Tower Mainz”, is a statement indicating that in Zollhafen, the former customs port, the signs point towards renewal.
Extract from an article in the “Hafen-Chronik”
Zollhafen's power center –
The boiler and engine house
Prof. Emil Hädler, chartered engineer, and Rudolf Coenen, chartered engineer
Without a doubt, Mainzer Zollhafen’s former “central machinery” can be considered one of the key buildings in the port area. Admittedly, originally, it was not the most important of the port buildings, but as soon as the first buildings went up it was erected as a power center. Today, it represents the only original architecture by Kreyssig on the site of the port still in existence. After the partial removal of later fittings, the boiler house and machine hall can once again be experienced in their original architectural state. The historical roofs had to be sacrificed to accommodate the new Kunsthalle building. The two halls are suitable for events and public use and, even as a shell, have a remarkable effect.
The building, or rather the ensemble of individual buildings clustered together is symbolic of the entire cultural landscape with its industrial undertones stretching from Ingelheimer Aue to Hafenstrasse. This symbolic quality was originally expressed in the architecture of a smokestack, now no longer in existence, and in the mighty rustic imitated ashlar stonework of the accumulator towers that are in stood, pars pro toto, for the "driving force" behind the energy supply in the port. Accordingly, in the discussions with the architect regarding the monument preservation the gap between the engine shed and the boiler house was accorded particular importance. The plan was for the erection of the "Leaning Tower of Mainz", a new landmark symbol for the Kunsthalle and for the Zollhafen project as a whole, repeating the earlier symbolic quality of the smokestack representing the power center. As a striking modern building section it encroaches only minimally on the existing building substance and has the pretension of being an intervention compatible with monument status.
Realized somewhat later, the engine shed for the port railway, located directly on the corner between Zollhafenstrasse and Rheinallee, does not belong to this ensemble in terms of function, but fits in perfectly with regard to facade design and structure. Here too, the historical roofs and the interior have been preserved in an unaltered state. It is well-suited to special uses connected with the remaining ensemble but requiring a certain separateness.
Aerial picture of Zollhafen Mainz in 1933
The greatest change was made to the fragment of the former warehouse building which, destroyed in the War and rebuilt incompletely, offers considerable scope for redesign. This section of the building was anyway not in keeping with the rest with its disadvantageous height which disturbed the originally planned line of the building as a low side wing of the former administration building. In this respect, the removal of the upper story at the end of the War tends to have a soothing effect. In the inside there are considerable opportunities for creating a large, continuous volume of space for multifunctional uses by removing the recent cellar ceiling and taking out various separating walls. The porter's building as a fragment, today rather isolated, of Kreyssig’s overall concept is difficult to recognize in its original function as a gate construction. The opposite section is missing and it is considerably disfigured in the inside. The careful removal of later fittings and a redesign are necessary.
In summary it can be noted that this diverse ensemble consisting of seven individual building sections manifests a surprising unity and completeness that does not in fact reflect the history of its genesis. Through permanent use, even at the time of the decline of the port, it fared reasonably well in terms of design and building construction and, with its noteworthy architectural quality, represents a benchmark. It seems an obvious step to start the future development of the port area at this point with a bold gesture, using the existing buildings, listed subsequently.
1. The engine shed. As the most recent element, today it can be experienced once again in its originality. It is not present on Kreyssig’s 1887 preliminary design drawing. In the stylistic terms it matches the architecture perfectly and could quite well have been designed in Kreyssig’s bureau. The demolition of the intermediate building in order to erect the Kunsthalle tower in 2006 lead to a surprise: opposite the boiler house’s smokestack a richly decorated facade with pilasters and diamond ashlars had been preserved, something nobody had expected at this quite invisible point.
2. The gap between the engine shed and the boiler house originally contained no buildings and was the site of the great smokestack that was dismantled in the 1950s. During excavation work for the Kunsthalle Tower the foundations were rendered visible. At this point it was possible to expose the arched foundations of the boiler house that reach deep into the soft subsoil of what used to be the Rhine sand.
3. The boiler house is largely preserved in its original form. In 2007 the original truss had to make way for the Kunsthalle’s new roof. Openings for windows were made in the east facade and closed with glass bricks. The hall was given an intermediate ceiling that was removed in 2006 as part of the gutting process. The exhaust duct of the boiler house was found in the subsoil in the course of excavation work and documented.
4. The accumulator tower was planned and executed as one of two. The second tower was completely prepared and its architecture is structured. Its butt was covered with a towed off shed roof. Intermediate ceilings put in at a later date have now been removed as part of the Kunsthalle building. The device for hanging a moving piston from a double steel girder on brackets is still in existence.
5. The machine hall with its flat sloping steel couple-close roof was given a clay conduit ceiling as a special constructional element, something that had to be removed as part of the work on the new Kunsthalle building. At subsoil level there is proof of two accessible foundations for steam engines. These allowed the machines to be serviced from below. The archers between the foundations are very impressive in spatial terms. The floor of the machine hall was fitted with a sophisticated terrazzo mosaic.
6. Various versions of the warehouse building were planned and it was finally executed with a richly decorated facade from the late historical period with two stories and a mighty roof. After it was destroyed in 1945 it was reconstructed in more modest terms with a simple nailed truss roof. One of two staircases was preserved as was the original structure of the cellar. As a “Zucker-Goebel” this section of the building saw the most alterations in the entire ensemble and as such was integrated as a torso in Kunsthalle concept.
7. The Octroi Bureau has been preserved in the shape planned by Kreyßig. It is missing its counterpart in the side wing of the former administration building, with which it formed an attractive gate setting. The gate could be monitored from a porter’s lodge. Nowadays the loge is walled up on the outside. A former office at the harbor entrance it boasted a sophisticated design with brick parapets and ashlar carefully integrated in the strip pattern of the facade.
Taken from the article in “Hafen-Chronik”