[{"command":"openDialog","selector":"#drupal-modal","settings":null,"data":"\u003Cdiv id=\u0022republish_modal_form\u0022\u003E\u003Cform class=\u0022modal-form-example-modal-form ecl-form\u0022 data-drupal-selector=\u0022modal-form-example-modal-form\u0022 action=\u0022\/en\/article\/modal\/7061\u0022 method=\u0022post\u0022 id=\u0022modal-form-example-modal-form\u0022 accept-charset=\u0022UTF-8\u0022\u003E\u003Cp\u003EHorizon articles can be republished for free under the Creative Commons Attribution 4.0 International (CC BY 4.0) licence.\u003C\/p\u003E\n \u003Cp\u003EYou must give appropriate credit. We ask you to do this by:\u003Cbr \/\u003E\n 1) Using the original journalist\u0027s byline\u003Cbr \/\u003E\n 2) Linking back to our original story\u003Cbr \/\u003E\n 3) Using the following text in the footer: This article was originally published in \u003Ca href=\u0027#\u0027\u003EHorizon, the EU Research and Innovation magazine\u003C\/a\u003E\u003C\/p\u003E\n \u003Cp\u003ESee our full republication guidelines \u003Ca href=\u0027\/horizon-magazine\/republish-our-stories\u0027\u003Ehere\u003C\/a\u003E\u003C\/p\u003E\n \u003Cp\u003EHTML for this article, including the attribution and page view counter, is below:\u003C\/p\u003E\u003Cdiv class=\u0022js-form-item form-item js-form-type-textarea form-item-body-content js-form-item-body-content ecl-form-group ecl-form-group--text-area form-no-label ecl-u-mv-m\u0022\u003E\n \n\u003Cdiv\u003E\n \u003Ctextarea data-drupal-selector=\u0022edit-body-content\u0022 aria-describedby=\u0022edit-body-content--description\u0022 id=\u0022edit-body-content\u0022 name=\u0022body_content\u0022 rows=\u00225\u0022 cols=\u002260\u0022 class=\u0022form-textarea ecl-text-area\u0022\u003E\u003Ch2\u003ENotre Dame: Medieval stonemasons built vaulted ceilings to protect against fires\u003C\/h2\u003E\u003Cp\u003E\u003Cstrong\u003EThe challenge of restoring Notre Dame after the fire in April presents an opportunity to unravel the techniques of the time, says Professor David Wendland, chair of construction history at Brandenburg University of Technology Cottbus-Senftenberg in Germany, who recently deduced how intricate, late Gothic vaults were constructed.\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EWhat is special about vaulted ceilings?\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u2018A vault is a self-supporting ceiling built of masonry which is stable due to its form - which is curved or double curved. A vaulted ceiling is a beautiful architectural feature but its main role is that the inside of the church is protected when the roof burns down.\u2019\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EGothic cathedral vaulting seems an extraordinary achievement.\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u2018If a vault has the wrong shape, you can build it as solid as you wish but it will fall down. We have the impression that they (medieval stonemasons) knew very well what they were doing. It happens very often that I just stand there with an open mouth and think: \u201cGosh, they were good.\u201d\u2019\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EYou investigated the design principles of late Gothic vaults through a project called \u003Ca href=\u0022https:\/\/cordis.europa.eu\/project\/rcn\/101156\/factsheet\/en\u0022 target=\u0022_blank\u0022 rel=\u0022noopener noreferrer\u0022\u003EREGOTHICVAULTDESIGN\u003C\/a\u003E. How were the vaults originally built?\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u2018We can suppose they were guessing, but that would have been very dangerous. In historical sources, we do find some collapses but there are very few. Somehow they did it right and what is interesting for us historically is to understand what their idea of mechanics was.\u003C\/p\u003E\u003Cp\u003E\u2018These structures are extremely complex in their shape because they need this curvature to be stable. The problem we were working on is: how could the master builder tell the stonemasons exactly what they had to do? They had to (transmit the necessary geometric information to) enable every stonemason to produce the piece exactly according to the project, and to make them fit together.\u003C\/p\u003E\u003Cp\u003E\u2018And the other problem is, how did they think that vaults work mechanically? Today we have tools in order to understand what makes a shape stable with a given setting of loads. We do not know how they understood when a vault was stable or not.\u2019\u003C\/p\u003E\u003Cp\u003E\u003Cfigure role=\u0022group\u0022 class=\u0022@alignleft@\u0022\u003E\n\u003Cimg alt=\u0022Craftsmen and technicians from the Strasbourg Cathedral restoration workshop replicated the medieval process behind making vaults at St. Anne\u0027s Church in Annaberg, Germany. Image credit - Mar\u00eda Jos\u00e9 Ventas\u0022 height=\u00221337\u0022 src=\u0022\/research-and-innovation\/sites\/default\/files\/hm\/IMCEUpload\/annaberg.JPG\u0022 title=\u0022Craftsmen and technicians from the Strasbourg Cathedral restoration workshop replicated the medieval process behind making vaults at St. Anne\u0027s Church in Annaberg, Germany. Image credit - Mar\u00eda Jos\u00e9 Ventas\u0022 width=\u00222008\u0022\u003E\n\u003Cfigcaption class=\u0022tw-italic tw-mb-4\u0022\u003ECraftsmen and technicians from the Strasbourg Cathedral restoration workshop replicated the medieval process behind making vaults at St. Anne\u0027s Church in Annaberg, Germany. Image credit - Mar\u00eda Jos\u00e9 Ventas\u003C\/figcaption\u003E\n\u003C\/figure\u003E\n\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EHow did you work out the methods behind the complex late Gothic vault at St Anne\u0027s Church in Annaberg-Buchholz, Germany?\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u2018It took scientists and really good craftsmen and technicians from the Strasbourg Cathedral restoration workshop to replicate the medieval process.\u003C\/p\u003E\u003Cp\u003E\u2018The design of the vault starts from the curves. You can draw them, and if they are spatial curves, you can develop them to the (two-dimensional) plane.\u2019\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ESo the key was to represent a three-dimensional set of curves in a two-dimensional plane?\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u2018The process is to understand how I can create a system which I can draw in the plane. And we were able to do that. We made a lot of 3D measurements on the vaults. We analysed these data on a computer and we reconstructed the geometry from there. That was the hypothesis on the (structural) design. Then we had to work out how that was done.\u003C\/p\u003E\u003Cp\u003E\u2018We tried to understand what design procedures for geometry they used. And, on the basis of what we know about the applied geometry of the time, we figured out what could have been the way, but we had to try it out.\u2019\u003C\/p\u003E\u003Cp\u003E\u003Cblockquote class=\u0022tw-text-center tw-text-blue tw-font-bold tw-text-2xl lg:tw-w-1\/2 tw-border-2 tw-border-blue tw-p-12 tw-my-8 lg:tw-m-12 lg:tw--ml-16 tw-float-left\u0022\u003E\n \u003Cspan class=\u0022tw-text-5xl tw-rotate-180\u0022\u003E\u201c\u003C\/span\u003E\n \u003Cp class=\u0022tw-font-serif tw-italic\u0022\u003E\u2018A vaulted ceiling is a beautiful architectural feature, but its main role is that the inside of the church is protected when the roof burns down.\u2019\u003C\/p\u003E\n \u003Cfooter\u003E\n \u003Ccite class=\u0022tw-not-italic tw-font-normal tw-text-sm tw-text-black\u0022\u003EHistorian Prof. David Wendland, Brandenburg University of Technology Cottbus-Senftenberg, Germany\u003C\/cite\u003E\n \u003C\/footer\u003E\n\u003C\/blockquote\u003E\n\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EHow did you achieve that?\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u2018We had to draw the (entire) vault in full scale, in the same size which (it) is supposed to be built. We did that on a plaster surface (of 180m\u003Csup\u003E2\u003C\/sup\u003E) where you can draw with a needle.\u003C\/p\u003E\u003Cp\u003E\u2018From this drawing, you have to produce templates (two-dimensional cut-outs that can be used to trace the cutting instructions onto the stone) and you have to understand how these templates work in order to make curved stone. So we made it all the way from what we would call today the executing drawing to the production of the stone member.\u003C\/p\u003E\u003Cp\u003E\u2018We now understand how the geometric design and the instructions for carving were made in the period of late Middle Ages and Early Modern (from around 1250 to late 16\u003Csup\u003Eth\u003C\/sup\u003E century).\u003C\/p\u003E\u003Cp\u003E\u2018Until now, only the modern procedures \u2013 from 19\u003Csup\u003Eth\u003C\/sup\u003E century onwards \u2013 were well-known.\u2019\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EWhy is it so important for restoration to understand how medieval vaulting was built?\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u2018The process you use for designing and planning also determines the shape. So if you use a modern process you will get a difference \u2013 maybe slight, but clearly visible \u2013 from the shape of the original.\u2019\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EWhat damage did Notre Dame\u2019s vaulting sustain?\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u2018The spire and the vaulting directly beneath it were (built in the) 19\u003Csup\u003Eth\u003C\/sup\u003E century. During the fire, the spire fell roughly in the direction of the main fa\u00e7ade and the greatest damage is there in the nave vaulting (12\u003Csup\u003Eth\u003C\/sup\u003E century). And there is one part of the 12\u003Csup\u003Eth\u003C\/sup\u003E century webbing (infill between the ribs), also in the transversal area, which has collapsed.\u0027\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EIs\u003C\/strong\u003E \u003Cstrong\u003Ethis earlier vaulting in Notre Dame simpler than the 19\u003Csup\u003Eth\u003C\/sup\u003E century structures?\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u2018In the vaults we studied (the late Gothic vaults in central Europe), the ribs are more complicated because they \u2026 have intersections on different levels. With Notre Dame, they are straightforward plain arches.\u003C\/p\u003E\u003Cp\u003E\u2018But in Notre Dame the webbings are of cut stone and in the period we studied they are made of bricks.\u003C\/p\u003E\u003Cp\u003E\u2018You can chop a piece away to make a brick fit in place. But with stones you cannot just stand on the scaffolding and chop them to the right size - you have to prepare them beforehand. There is no book where you can read (how they did) that.\u2019\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EHow should the Notre Dame restoration be done?\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u2018From the conservation point of view, you should reproduce the 19\u003Csup\u003Eth\u003C\/sup\u003E century vault (according to 19\u003Csup\u003Eth\u003C\/sup\u003E century methods). But we should definitely reconstruct the medieval vaults as they were in the Middle Ages and we still have to understand how this was done.\u003C\/p\u003E\u003Cp\u003E\u2018I think we should use this very sad moment to learn how this was done, to restore it in a way that also makes us understand very well what is there and to have this knowledge again in our culture.\u2019\u003C\/p\u003E\u003Cp\u003E\u003Cfigure role=\u0022group\u0022 class=\u0022@alignleft@\u0022\u003E\n\u003Cimg alt=\u0022According to Prof. Wendland the damaged vaults of Paris\u0027 Notre Dame should be restored according to original methods. Image credit - Thesupermat\/ Wikimedia Commons is licensed under CC BY-SA 3.0\u0022 height=\u00221468\u0022 src=\u0022\/research-and-innovation\/sites\/default\/files\/hm\/IMCEUpload\/nef-ndp.jpg\u0022 title=\u0022According to Prof. Wendland the damaged vaults of Paris\u0027 Notre Dame should be restored according to original methods. Image credit - Thesupermat\/ Wikimedia Commons is licensed under CC BY-SA 3.0\u0022 width=\u00222000\u0022\u003E\n\u003Cfigcaption class=\u0022tw-italic tw-mb-4\u0022\u003EAccording to Prof. Wendland the damaged vaults of Paris\u0027 Notre Dame should be restored according to original methods. Image credit - Thesupermat\/ Wikimedia Commons is licensed under CC BY-SA 3.0\u003C\/figcaption\u003E\n\u003C\/figure\u003E\n\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EWon\u2019t that take too long? French President Emmanuel Macron wants it restored in time for the Olympics in 2024.\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u2018We (historians and restoration experts) are all a little afraid that there is now a rush, but \u2026 I think this is feasible if we organise, concentrate and mobilise a lot of resources.\u003C\/p\u003E\u003Cp\u003E\u0027There is now an initiative of \u003Ca href=\u0022http:\/\/scientifiquesnotre-dame.strikingly.com\/\u0022\u003Escientists\u003C\/a\u003E (with already more than 170 members of many different areas) that tries to bring together all the know-how necessary for reconstructing Notre Dame in the most authentic and most respectful way. It is definitely feasible.\u2019\u003C\/p\u003E\u003Cp\u003E\u003Cem\u003E\u003Cstrong\u003EThis interview has been edited for length and clarity.\u003C\/strong\u003E\u003C\/em\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cem\u003EThe research in this article was funded by the EU\u2019s European Research Council. If you liked this article, please consider sharing it on social media.\u003C\/em\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cdiv class=\u0022moreinfoblock\u0022\u003E\n \u003Ch3\u003EThe Issue\u003C\/h3\u003E\n \u003Cp\u003EStarting in 2019, the European Commission has committed the next two years to preserving and promoting cultural heritage through \u003Ca href=\u0022http:\/\/europa.eu\/rapid\/press-release_IP-18-6661_en.htm\u0022 target=\u0022_blank\u0022 rel=\u0022noopener noreferrer\u0022\u003Efive key approaches\u003C\/a\u003E. These actions include funding more inclusive cultural experiences through pop-up exhibitions in public spaces, rewarding cities for their original approach to tourism \u2013 Helsinki and Lyon share the title of being 2019\u2019s European capital of \u2018intelligent tourism\u2019 \u2013 and protecting Europe\u2019s endangered heritage through renovation to withstand events such as earthquakes. Following the fire in April that engulfed Paris\u2019 Notre Dame cathedral, the EU is working to establish a \u003Ca href=\u0022http:\/\/europa.eu\/rapid\/press-release_MEX-19-2390_en.htm?locale=en\u0022 target=\u0022_blank\u0022 rel=\u0022noopener noreferrer\u0022\u003Ebetter mechanism\u003C\/a\u003E for pooling together funds and talent to safeguard vulnerable cultural heritage. The last two aims include supporting the mobilisation of knowledge and the development of cultural heritage skills and professions as well as boosting international cooperation by working with other countries to protect heritage.\u003C\/p\u003E\n\u003C\/div\u003E\n\u003C\/p\u003E\u003C\/textarea\u003E\n\u003C\/div\u003E\n\n \u003Cdiv id=\u0022edit-body-content--description\u0022 class=\u0022ecl-help-block description\u0022\u003E\n Please copy the above code and embed it onto your website to republish.\n \u003C\/div\u003E\n \u003C\/div\u003E\n\u003Cinput autocomplete=\u0022off\u0022 data-drupal-selector=\u0022form-3x0qzmttpdwpany2-7oyrojyj-hx8tj5zx0dfxss56o\u0022 type=\u0022hidden\u0022 name=\u0022form_build_id\u0022 value=\u0022form-3x0QzMTtPDWpany2_7oYroJyJ-hX8Tj5zx0DFxss56o\u0022 \/\u003E\n\u003Cinput data-drupal-selector=\u0022edit-modal-form-example-modal-form\u0022 type=\u0022hidden\u0022 name=\u0022form_id\u0022 value=\u0022modal_form_example_modal_form\u0022 \/\u003E\n\u003C\/form\u003E\n\u003C\/div\u003E","dialogOptions":{"width":"800","modal":true,"title":"Republish this content"}}]