Knowledge sharing Naarden Fortress

We often get questions about how we manage and maintain the fortifications of Naarden. Our building historian and expert in the field of fortifications, Jeroen van der Werf, explains how we share knowledge with parties and people from the heritage sector. This happens in many areas and in many places: from Finland and South Korea to the fortress itself.

“Knowledge is good to have, but even better to share. Knowledge only comes to life when others have access to it. That goes both ways. For us, it is also important and interesting to learn from others. The perspective of another ensures that you remain critical of your own work and vision. So always ensure an open and unbiased exchange of knowledge and ideas. In addition, it is simply great fun to exchange ideas with other experts and enthusiasts.”

Historical building materials

One of the areas in which this knowledge sharing takes place is in the field of historical building materials. For example, Jeroen recently conducted research into the 12 concrete shelters that were built on the covered road in Naarden between 1895 and 1906. In 2022, we restored one of these shelters (building W1). Prior to this, an archive study was conducted by Jeroen and Federica Marulo, our former trainee.

They processed the results of this research in an article about the composition and use of this historical concrete. A striking result of their research was that, after looking at the specifications from the National Archives, they discovered that each shelter had a different concrete recipe. What was the reason for this? The explanation is in the article.

Jeroen and Federica were allowed to present their results at 8ICCH , an international conference for building history in Zurich. Jeroen also presented the results during the meeting 'Fortifications then and now' of the Cultural Heritage Agency of the Netherlands in Amersfoort on June 21, 2024.

The challenges of restoration practice

Fortifications all over the world face similar challenges. That is why an initiative was set up by Suomenlinna, a large Finnish fortification complex in the bay of Helsinki. This complex is a UNESCO World Heritage Site, just like the fortifications of Naarden. They have issues about the increase in tourists and the consequences of climate change. These new challenges require a different approach to maintenance and restoration. That is why we were looking for partners with similar issues to brainstorm about and exchange experiences. We were asked to think along.

In September, this trajectory will start with a symposium on restoration issues and climate change in Finland. Jeroen will talk about our approach to the fortifications in Naarden. Next year, a visit will take place to the other partners, in Mont Dauphin and Antibes, and the group will visit the Naarden fortress. At the end of the trajectory, the findings will be summarized to arrive at guidelines that offer other fort owners and fortified cities tools for dealing with this special heritage.

Students and study days

Closer to home, we are also active in sharing knowledge about fortifications. Jeroen regularly gives lectures on various subjects related to the history of fortifications or to the daily restoration practice in Naarden. For example, he gives a lecture every two years on the development of fortification construction in the Netherlands for the Building History course at the Hogeschool Utrecht. This year, the lecture on forts and fortifications will take place on 9 October in the Gele Loods in Naarden.

Another example is the lecture for the study day of the WTA Netherlands-Flanders, which will be held in Mechelen in November. This year the theme of the study day is 'Heritage in the water'. Jeroen will talk about the role of water in the restoration practice, in particular about the approach to the waterline and the large water load that acts on the masonry from the earthworks behind the walls.

Research and publications

Publishing and making research results available is an important aspect of knowledge sharing. That is why a large part of all of Jeroen's publications and research is collected on our publication page.

There has also been a book published about the fortifications of Naarden, written by Jeroen. This was published last year in English, and now also in Korean! This Korean version of the book contains the same chapters as in the English and Dutch versions, but also an additional chapter about the use of brick in the Netherlands and South Korea, with similarities and differences. This comparative research was done following a knowledge exchange about Korean and European fortifications in 2022 and 2023.