The Crown Bridges Light Rail project includes the construction of a 10km tram line that will connect the Laajasalo, Korkeasaari, and Kalasatama districts to Hakaniemi in Helsinki, Finland.
Also known as Kruunusillat light rail, the project will offer a secure and fast public transportation route to Helsinki’s city centre in addition to creating a seaside route for cyclists and pedestrians.
The general plan for the project was announced in 2002 and the specifications for the development as a light rail connection were added in 2008. Helsinki City Council decided to implement the project in August 2016.
The project is being developed in two phases, with phase one investment estimated at €326m ($383m). Construction on phase one of the project commenced in 2021 and is scheduled to be completed in 2027.
The tramway is expected to be used by approximately 37,000 passengers a day by 2040.
Crown Bridges Light Rail project details
The Crown Bridges Light Rail project includes the construction of a set of three bridges specifically for the tram, including the Merihaansilta bridge, the Finkensilta bridge, and the Kruunuvuorensilta bridge.
The main Kruunuvuorensilta bridge, spanning 1.2km, will be developed between Korkeasaari and Kruunuvuorenranta in Laajasalo. It is set to be the longest bridge in Finland and have a lifespan of 200 years.
The Merihaansilta bridge between Hakaniemi and Kalasatama will be a 412m-long pier-like bridge, featuring a lifting steel structure while the Finkensilta bridge between Kalasatama and Korkeasaari will be a 293m-long prestressed concrete girder bridge.
In addition, the project includes the construction of two bridges in Hakaniemi. The Hakaniemensilta bridge, which was originally built in the 1960s, is in poor condition and will be replaced with a new 230m-long composite girder bridge.
The Nakinsilta bridge, which is mainly used by pedestrians and cyclists, will also be rebuilt with a new 176m-long concrete bridge to accommodate the traffic changes in the area.
Kruunuvuorensilta bridge details
The Kruunuvuorensilta bridge will be a cable-stayed composite structure with a concrete deck. It will feature a diamond-shaped 135m-high central pylon, representing the former crown control of the bay region.
The bridge will have two abutments and 11 intermediate supports. It will have a clearance height of 20m, which enables the largest sailing boats to cross under the bridge, and a free span width of 30m.
The bridge will have a rail corridor and a cycling lane for use by cyclists, pedestrians, and public transportation. The bridge deck will be 15m-19m wide with a 9m-wide rail lane, a 3m-wide bicycle lane, and a 2m-6m wide pedestrian pavement.
Vehicle access to the bridge will be available for emergency services.
Crown Bridges Light Rail project construction
The first phase of the project will focus on the construction of a tramway connection between Laajasalontie and Hakaniemi. It also includes the construction of the Nakinsilta, Finkensilta, and Kruunuvuorensilta bridges.
The second phase will include the construction of the tramway line between Hakaniemi and Helsinki’s central railway station, which will commence after 2026.
Construction on the project began in 2021 in Hakaniemi and Kruunuvuorenranta, along Koirasaarentie. Track installation works on the tramway commenced in May 2022.
Work on the Kruunuvuorensilta bridge began in April 2022 and the main approach spans were completed by June 2023.
The Merihaansilta bridge is scheduled to be completed in 2023, followed by the Hakaniemensilta bridge in 2024, and the Kruunuvuorensilta bridge in 2025.
The Crown Bridges alliance consortium comprising the City of Helsinki, Helsinki City Transport, NRC Group Finland, Ramboll, YIT, and Sitowise is responsible for the development of the project.
NRC Group Finland is a rail infrastructure company while Ramboll is an engineering and architecture consultant, YIT is a builder, and Sitowise is an engineering services provider.
The Kruunusillat joint venture (JV) comprising YIT and Kreate, a general contracting services provider, was awarded a €123m contract to build the bridges of the project. The JV will also undertake earthworks, roadway construction, and municipal engineering works.
The Kruunuvuorensilta bridge was designed by Knight Architects and WSP, who continue to serve as technical advisors to the project.
Engineering and architecture consultancy Sweco is providing engineering services for the project.
Mincon, an engineering company, was awarded a contract to provide drilling expertise using its patented Spiral Flush technology and M-Wall solution.
Blare Technologies, a software solutions provider, and Sitowise developed a digital twin model of Helsinki to provide an online presentation of the Crown Bridges Light Rail project.
Finally, information manager M-Files’ metadata-driven document management platform is being used to enable secure access to information and documents for project stakeholders.
The Crown Bridges Light Rail project is part of the City of Helsinki’s aim to increase sustainable passenger traffic by designing routes for pedestrians, bicycles, and public transportation.
The project will reduce the distance between Kruunuvuorenranta and the city centre from 11km to 5km. It will ensure smooth traffic flow, reduce congestion, and improve transit options to and from Korkeasaari.
In addition, it is expected to increase the number of tram users by seven to nine million a year. It will also create a cycling route/walkway along the light rail line, allowing access to the Kalasatama, Korkeasaari, Mustikkamaa, and Laajasalo regions by bicycle or foot.
The bridge will run close to the Korkeasaari island, where the Korkeasaari Zoo is located. It will provide easy access to the zoo and emergency vehicles.