Ekaterina Nozhova is a co-author of a new international study on Shukhov's work, and the author of a dissertation devoted, to a large extent, to the history of the construction of the tower on Shabolovka (the dissertation was written at the Federal Institute of Technology Zurich). Ekaterina is a member of several European societies of construction historians, whose heads recently signed an open letter to the President of the Russian Federation with a request to prevent the loss of the Shabolovskaya Tower and an offer of "professional support of the scientific and engineering communities."
Ekaterina told us about the design features of the tower, attempts to examine it, and also shared her opinion on the possibility of reconstruction of the monument without the construction of expensive forests (the declared value of which, as follows from the explanatory note to the draft government decree on dismantling the tower, actually made the idea of dismantling a priority a monument of world significance).
Archi.ru:
How did the international project on the study of the work of Vladimir Shukhov come about?
Ekaterina Nozhova:
- The joint research project of Germany, Switzerland and Austria was initiated by three major institutions - the Technical University of Munich, the University of Innsbruck, the Federal Institute of Technology Zurich (ETH), of which I am a representative, and personally by Rainer Grefe, the author of the first detailed book on Shukhov's activities, which was released in 1990. Rainer Grefe turned to his colleagues with a request to help him in the release of the next edition about Shukhov, supplemented with the latest materials and projects. In total, we have devoted more than three years to this work, starting the study in 2010. The final report on the results of the work done is currently being prepared. I am convinced that the information obtained within the framework of this project can be useful in carrying out restoration work.
Who initiated the open appeal to the President of the Russian Federation?
- For a long time we followed the fate of the Shukhov Tower. In connection with the information that arose about its dismantling, it was decided to send an open letter to Vladimir Putin, signed by representatives of the National Societies of America, Germany, France, Spain, Italy, Switzerland, Great Britain and Belgium. In our appeal, we offer assistance not only in matters of consultation, we are ready to actively participate in the restoration, provide our own specialists. The first version of the letter outlined even more specific steps : holding a congress, discussing all materials and samples that can be provided to us, analysis, expertise, and the first measures for the conservation of the tower.
– In your opinion, what hinders the tower conservation today? Why was the decision to dismantle it made?
– The problem is that the tower has an owner who just doesn't know what to do with such a complex 150-meter structure. Indeed, this project requires a delicate and comprehensive approach. The work on it cannot be entrusted to one separate bureau. Here you will need very diverse specialists: measurement engineers, structural analysis specialists, specialists in metals and their corrosion. It is possible that such a team can be assembled in Russia as well. We are ready to provide our specialists right now.
Another major problem is the lack of detailed documentation. Only a few drawings have survived, and they are rather schematic. In one of the drawings, the joints of the sections do not coincide with those that can be seen on the constructed tower. There is reason to believe that this drawing was made as part of the descriptive documentation and does not date from 1919, but from the early 1940s. This version is also supported by the fact that an organization that appeared only in 1932 is indicated in the cap of the drawing signature. Another document available only gives an idea of the proportions of the structure. The surviving sketch of the foundation is very different from the foundation of the constructed tower, and the drawing of the joint between the two sections has come down to us in a very poor condition, which does not allow us to get a complete picture of the details of the structure.
When collecting all the source materials, we also turned to TsNIIPSK im. Melnikov, created on the basis of the firm of Alexander Bari, in which Shukhov worked. The institute has preserved several surveys from 1947 and 1971. Galina Shelyapina, a leading engineer of the institute, showed me these drawings. But when I personally climbed the tower, it became obvious that they also have a significant discrepancy with reality. It is not enough to know just the proportions, you need complete information about the joints, inclined posts, which were assembled from several profiles, which was directly related to the installation method without scaffolding. Unfortunately, we do not have this information.
Therefore, before talking about conservation and restoration, it is necessary to carry out thorough measurements, surveys and draw up a map of the object with all its damages. The next step is to create a tower documentation with the exact dimensions of all profiles and an assessment of their condition.
– The fact that the tower is in dire need of renovation has been debated for a very long time. What has prevented you from carrying out the survey you are talking about so far?
– The object is very large and complex. It should be understood that even a large team of climbers is not able to manually measure the tower in a short time.
A year and a half ago, together with the Russian Academy of Sciences and the State Institute of Aviation Systems, we tried to conduct a survey using a small aircraft - an octocopter. It took us and the director of the institute Sergei Zheltov a year and a half just to get permission to fly around the tower. When this permission was obtained, it turned out that a huge number of cellular sensors were installed on the tower, which create a powerful magnetic field. This field did not allow to fully control the octocopter, and, therefore, to fulfill the plan. However, other companies have tried to implement similar projects besides us. Sergey Zheltov continued the measurement project with ZALA AERO. They managed to get pictures taken using a photogrammetric survey. These photographs reproduce a fairly accurate model, but the details cannot be reproduced from them. We faced the same problem when studying materials prepared by the Academy of Sciences two years ago in the course of laser scanning of the tower. This work was carried out under the guidance of Andrey Leonov from the Institute of History, Natural Science and Technology. They managed to make the most accurate model of all existing ones. But it also gives only the geometry of the structure, without recreating the nodes and joints.
– It is clear from your story that the analysis of such a large and complex object as the Shukhov Tower is quite difficult from a technical point of view. However, in your appeal to the President of the Russian Federation, you insist on an examination. Do you have any algorithm of actions?
– If you combine all the methods I have described above, try once again to work with an octocopter or a camera on a mobile platform, apply photogrammetric analysis, laser scanning, photographs and manual examination in the most inaccessible places, then it is quite possible to get a fairly accurate idea of the current state of the tower. This does not require the construction of expensive scaffolding.
– Are you against scaffolding?
– The fact is that there is a project developed by the Quality and Reliability company, which received the right to design based on the results of the RTRS tender. However, this draft has not been published anywhere. It was only in November 2012 that it was presented at a press conference at MGSU-MISS, which was open, but did not attract a lot of public, which is why this event did not receive wide publicity. I was personally there and even then I had a lot of questions. In particular, the cost of scaffolding, according to the company's calculations, was three times higher than the entire budget allocated by the state for the reconstruction of the monument. Based on these calculations, it was concluded that the restoration of the tower in place is too expensive an undertaking, it is much easier to demolish it. This raises the question: is scaffolding really necessary? The properties of Shukhov structures are such that even if several elements are damaged, the structure remains very stable, since the loads are evenly distributed over the entire structural mesh. For example, when we started the reconstruction of the 128-meter Shukhovskaya tower on Oka NiGRES, vandals sawed off 16 of its 40 supporting legs, but it resisted, withstood the colossal load and is now restored.
It is also surprising that today all information about that November conference has disappeared from the public domain, including videos posted on YouTube. No one today knows how detailed this project was. Whether measurements were made, how well it was done, etc.
– If the proposal for the conservation of the tower is approved, what other problems will be faced during the subsequent restoration?
– A serious problem is the quality of the metal used in the construction of the Shabolovskaya tower. It was built from what at that time could be obtained from warehouses. And this, as a rule, was a low quality metal with a high content of phosphorus and other impurities. It must be said that the upper sections rusted much stronger than the base, which was apparently made of another alloy, which turned out to be less vulnerable. At the time of the tower's construction, at least five types of steel production were in use in Russia. According to statistics, only 12% of the metal met the then accepted standards, everything else had no quality guarantees. Of course, the steel used for the construction of the Shukhov Tower is very different from modern alloys. Therefore, the most serious analysis is necessary here in order to avoid a conflict between different alloys, which will inevitably lead to even more corrosion. Similar mistakes have already been made during the previous repair work on the structure.
– Is it possible to reassemble the tower unchanged if it is dismantled?
– This will be extremely difficult to do. And most importantly, I see no reason why it needs to be disassembled. The first signs of corrosion appeared in 1991. If measures were taken immediately, then conventional metal processing could be dispensed with. Now everything is much more complicated. But to speak about the threat of destruction, it seems to me, is premature. If, nevertheless, a decision is made to dismantle it, the damage to the monument will be colossal. On the profiles, traces from the installation have been preserved, which, most likely, no one will pay attention to when disassembling the tower. And this is a very important detail that cannot be restored later. During the construction, all the elements were mounted on the ground and lifted up on special wooden structures using winches. As a result, holes with a diameter of about 2 cm remained on the profiles, along which the entire installation process can be recreated today. When the tower is disassembled, all this layer of information will simply disappear.
One more thing - the tower is assembled with rivets, which the climbers lifted up in leather bags specially sewn for this. In a suspended state, they heated and fastened these rivets. That is, it was absolutely incredible, handicraft efforts that can now be completely lost. Indeed, during disassembly, rivets will simply be cut off, and new ones are not produced anywhere today. For example, in one of the restoration projects in Switzerland, the rivets had to be ordered from a blacksmith. And this is only a small fraction of the irreparable damage to the monument.
The geometry of the tower is very complex. It is easier to recreate a flat structure, whereas a hyperbolic one has twisted profiles slightly rotated around its axis. Here we are dealing with 3D and very complex nodes. Each intersection has its own angle. The difference in values often does not even reach 1 mm, but even such a tiny difference is very important for subsequent installation. I do not know of other designs that have been cut to the required millimeter precision.
But our main message is an urgent examination. Until it is carried out, it is impossible to assess the condition of the structures. And as a result of this, no steps at all can be taken, especially since the building cannot be dismantled. If the analysis is started without examination, then the initiators of the dismantling will have the opportunity to completely abandon its further restoration, citing the terrible state of the parts. I am personally convinced that the Shukhov Tower can be restored on the spot.
