Tunnel between Santos and Guarujá will require a large construction site

With an investment of €7.1 billion, the construction of the Fehmarnbelt Tunnel between Denmark and Germany impressed Brazilian authorities (Maurício Martins)

While the construction of the world’s largest immersed tunnel covers an area of 1.5 million square meters (m²)—equivalent to more than 300 soccer fields—in Denmark, the future dry connection between Santos and Guarujá does not yet have a defined location for the construction site. Although on a smaller scale, the Brazilian tunnel will use the same construction methodology applied in Europe.

The Fehmarnbelt Tunnel, which will connect Denmark to Germany, began construction in 2020 and is expected to be completed in 2029. On the Danish side, work is underway on a vast site in Rødbyhavn, where 79 massive concrete elements—each weighing over 70,000 tons—are being produced and will later be submerged to form the 18-kilometer connection beneath the Baltic Sea. The operation is being led by Femern, a state-owned company created specifically to execute and manage the project.

In Brazil, the situation is different. The Santos-Guarujá tunnel, which will span 1.5 km (870 meters of which will be submerged), still lacks a designated area for the construction of its modules. According to a statement from the State Secretariat for Partnerships and Investments (SPI) to A Tribuna, “the definition of the construction site location will be the responsibility of the future concessionaire, to be selected after the auction scheduled for August 1.”

Between doubts and lessons The lack of a defined construction site has raised concerns among local authorities, who embarked on a technical trip to Europe to closely study the engineering models used in similar projects. The delegation visited the Fehmarnbelt Tunnel works and the Øresund bridge-tunnel, which connects Copenhagen to Malmö, Sweden. The goal was to observe execution challenges and the urban and operational impacts.

"Since we are going to set up the construction site in the Baixada Santista, this was precisely one of the main reasons for this trip: to examine the mouth, the entrance, the tunnel gate for urban implantation, and the entire movement of equipment", said the mayor of Santos, Rogério Santos (Republicanos), who was part of the Brazilian delegation. "All of this will be planned. Some land has already been surveyed by the state and federal governments. But it really is quite a complex situation."

Federal deputy Paulo Alexandre Barbosa (PSDB) emphasized that the project requires a large construction site: “These are the challenges of the project. The modules are manufactured out of the water and then submerged. The key for this project to happen is the cooperation of all parties involved: Federal, State, Judicial branches, and local governments.”

For Luiz Felipe Tonelli Távora, Superintendent of Infrastructure Development at the Santos Port Authority (APS), seeing the Danish project up close was crucial.

“The construction methodology is very similar to what will be used in our region. It's a very well-organized project, with consolidated phases and clearly defined modules. The project in Denmark is still in the dry phase, and the most challenging part is the wet phase, due to the logistics of transporting the heavy components. We will need to apply the same technology in Santos.”

Technical mission The trip to Europe was organized by the parliamentary fronts for the Santos-Guarujá Dry Connection and for Ports and Airports of the Chamber of Deputies, with support from the Instituto Brasileiro de Infraestrutura (IBI).

The Brazilian delegation, consisting of more than 40 leaders, also visited the Øresund bridge-tunnel, which connects Denmark to Sweden through a combination of cable-stayed bridge, artificial island, and immersed tunnel.

Commitment The trip also served to reinforce the political commitment to the advancement of the project. “We’re beginning to dream of things truly happening”, said federal deputy Paulo Alexandre Barbosa (PSDB). “We have to learn from those who are ahead of us. Our tunnel will be smaller, but it’s essential that we learn from these examples to avoid setbacks.”

Feeling confident after the visit, mayor Rogério Santos (Republicanos) believes the tunnel is becoming a reality. “It’s the first immersed tunnel in Brazil. It had to be in Santos, which sets so many examples. It’s not easy, but it’s the largest investment under the PAC and will create many jobs and improve people’s lives.”

São Paulo’s Vice-Governor Felício Ramuth (PSD) reiterated that the project is well on track: “The auction is scheduled for August 1, with contracts signed by the end of the year. In five years, the tunnel will be ready”, he said. “The state is making the right choice by selecting this tunnel technology”.

According to him, the project could involve up to 9,000 workers, including both specialized and general labor. “It involves nearly R\$ 6 billion in investment. We already have interested groups, and starting in August, we will have a precise timeline to turn this dream into reality. ”

Structure could drive regional development More than just an engineering feat, the future Santos-Guarujá tunnel could contribute to economic development, urban integration, and regional transformation. This is the perspective of experts and authorities who participated in the technical mission to the Fehmarnbelt Tunnel construction site between Denmark and Germany and the Øresund bridge-tunnel linking Denmark and Sweden.

Mário Povia, president of the Instituto Brasileiro de Infraestrutura (IBI), highlighted that Brazil will adopt the same methodology used in the European tunnel. “There it’s 18 kilometers, here it will be about one. In terms of technology, what we saw was fantastic. The layout of the construction site, the efficiency—we must draw from all of it.”

According to him, the main challenge in Brazil will be logistical. “We cannot stop the port. Changing the tire while the car is moving may be the biggest difference compared to Europe. But the visit allowed managers from all three levels of government to see how a project of this scale is conducted.”

In addition to directly impacting mobility, the tunnel has the potential to catalyze new economic vocations. Pedro Henrique Jocondo Guerra, chief of staff to Vice President Geraldo Alckmin (PSB) and president of the Fiscal Council of BNDES, stressed that projects like this drive tourism, commerce, innovation, and entrepreneurship.

“They (in Europe) are a benchmark in modal integration. Santos is pioneering this dry connection technology in Brazil. The tunnel can attract companies, serve students, encourage investment, and foster a more dynamic and connected environment”, he said.

High technology In the view of Marcelo Sammarco, IBI vice president, the impact of the project goes beyond mobility: “The tunnel is a high-tech project that has revolutionized local logistics (Germany–Denmark) and can be replicated in Brazil. The bridge between Denmark and Sweden efficiently integrates passengers and cargo. This experience can be leveraged in many projects across Brazil.”

For businessman Sávio Leal, director at Terracom, the technical visit helped understand the complexity of the project and its maintenance challenges. “It’s not just about building it, but also about monitoring it afterward. It was an opportunity to see how it works in practice.”

The tunnel will be 1.5 km long, with three lanes in each direction (one adaptable for light rail transit), a bike lane, and pedestrian access. With an expected investment of R\$ 6 billion, the 30-year concession aims to generate 9,000 jobs and replace the current ferry system, which transports over 35,000 people daily between Santos and Guarujá.

The dry connection has been awaited for decades and may mark the beginning of a new phase of sustainable and intelligent growth in the Baixada Santista.