September 2025

By: Max Majoor, Maria Marsella, Patrick Werneke, Martine Oudenhoven, Pep Freixanet

The Einstein Telescope Organisation (ETO) consists of multiple departments, one of which is the Engineering Department. Engineering plays a vital role in bringing the Einstein Telescope from concept to reality. Patrick Werneke, Head of the Department, Maria Marsella, Head of the Civil Engineering team, and mechanical engineer Max Majoor share insights into their work and daily operations, providing a deeper understanding of the department's significance.

Engineering is often seen as the backbone of large scientific projects. What is the role of ETO's Engineering Department?

Patrick: In my eyes it is important to realise that the actual design and construction of the Einstein Telescope is an engineering project. This means that engineers are essential, and must be integrated into a department that naturally aligns with the scope of ETO. The role of scientists remains crucial, while they define the scientific goals and ensure that ET meets its research objectives, the realisation of those goals depends on engineers. I often like to draw a comparison with CERN: where relatively few CERN staff do actual science and the majority of the work for the accelerator is carried out by engineers.

Maria: The Einstein Telescope is a highly complex research infrastructure. It will be constructed underground and will host advanced instrumental systems. To ensure scientific requirements are effectively translated into engineering performance and design, our expertise and efforts are essential.

Max: I like to summarise it this way: our role is to make the scientists' imagination a feasible reality.

Visualisation of a baseline design for the Einstein Telescope, one of the activities in which ETO’s engineering department plays a key role. Credits: Jonathan Bratanata and Max Majoor.

The success of a project of this magnitude relies on the expertise and dedication of a well-structured team. What does the department itself look like?

Patrick: The people in our department have different engineering backgrounds: civil engineering, mechanical engineering, and architecture.

Maria: There are approximately 14 people in the team, who have been identified by the founding agencies participating in the ET project. We are supported by certain experts who are acting as consultants and advisors.

Patrick: We have an excellent working relationship with the engineers from CERN, so the feeling is more like they are our colleagues, and they also actively participate in our internal ETO meetings.

With such a diverse and international team, communication is key. How do you manage to stay connected across different locations?

Maria: Indeed, we are very international and spread across various locations: Nikhef Amsterdam, INFN Rome and INFN Frascati, CERN Geneva, IFAE Barcelona, CNRS-IJCLab in Orsay, CNRS-LAPP in Annecy, FHNW Basel. So that's five countries in total: Switzerland, Spain, Italy, the Netherlands and France!

Patrick: And it is indeed a challenge to make sure we stay connected. We have monthly meetings with the whole department via Zoom, and different subdepartments have their own Zoom meetings. We try to meet once per month in person to discuss civil engineering, and vacuum every three months. I do miss a kind of 'physical home' for ETO and the Engineering Department, where we can easily meet and do work in between meetings. For now, CERN is providing that home in a way.

Patrick Werneke, Romano Meijer and Max Majoor visiting LIGO Hanford Observatory, posing in front of a test setup for welding suspension-wires onto optical substrates.

Looking back at the last year, the department has reached some important milestones. What have been your key achievements?

Patrick: I would say actually three main things: First, we have made real progress in our collaboration with the local teams. That gives us more control over the project when it comes to engineering. We also had a very successful workshop with the local teams of Sardinia and the Euregio Meuse-Rhine at CERN. Secondly, we have also booked nice results with the optical and detector layout, which was a lot of work, but it was very successful. And thirdly, the first version of the design report for the vacuum pipe design was published.

Max: I am happy with the increased participation in the Engineering Department — we have grown and people have become more engaged. And our department has also become more visible in ETO and in the scientific collaboration. Those are also good results.

Maria: For me it's also three things. The main accomplishment is that the first updates of the triangle and L-shaped layout in digital format were finalised. Secondly, the understanding of the expected outcomes from our activity is growing. The local teams, scientific collaboration and many others understand better what they can expect from us. And our effort is very much dedicated to guarantee that the preparatory activities at the candidate sites are conducted in a similar manner, thus allowing for a fair comparison of proposals.