The Crown Bridges alliance utilises Sweco’s railway design expertise
The Crown Bridges alliance utilises the best railway design expertise in Finland. A new light rail line will be built in the alliance, but on a practical level it is a larger urban development project. Sweco’s special strength lies in its wide range of services ranging from railway and railway electrical design to landscape and street design as well as project management.
Crown Bridges promotes Helsinki’s low-emission traffic
Crown Bridges is one of Finland’s largest public transport projects and at the same time a way to promote Helsinki’s lower-emission urban transport. Hakaniemi, Laajasalo, Korkeasaari Zoo and Kalasatama will be connected by three new bridges and light rail with pedestrian and cycling routes. Sweco has been involved in all phases of the tram alliance from the very beginning.
“The tramway alliance is more of an urban development project, even though it mainly involves the construction of a tramway,” says Mikko Rislakki, Sweco’s Business Development Director, who is a member of the alliance’s management team. The areas built around the tramway and directly related to it have a positive impact on both Helsinki’s cityscape and urban development.
An alliance works like a company where everyone has the same mindset. Design tasks are distributed between different planning parties on the basis of the “best for the project” principle. The plans are also developed and, if necessary, changed during construction according to the client’s or end user’s goals.
“Working closely together with design partners, the client and contractors gives Crown Bridges its own great flavour,” Rislakki says.
Project management expertise is emphasised in the tram alliance
The alliance utilises the expertise of the entire Sweco Group, but the most important areas of strength are, for example, street and municipal engineering design and railway design.
“We have also provided design managers for all subprojects, with the exception of bridge and water construction,” says Heikki Putkonen, Project Manager at Sweco. According to him, the strength of the alliance model can be seen in its ability to adapt and react when schedules or boundary conditions change. A good example is the water permit for Hakaniemenranta, which was waited for two years. “We were able to do other work instead of shore construction because the alliance enables changes in work phases and schedules.”
In an alliance that overlaps with many other projects, project management expertise is important. At the same time, for example, the Laajasalontie separate project and the Kruunuvuori bridge are being built in the area, which will form the basis for the tramway connection.
“Systematic project management practices are needed in both scheduling and partitioning of work,” says Sweco’s Project Manager Jussi Utti. He is responsible for leading the design of the Railway Electricity and Technical Systems subproject with experience gained from Länsimetro. “We also try to identify problem areas on the construction site proactively already on the drawing board.”
A responsible public transport project benefits from the circular economy
As a public transport project, Crown Bridges is already responsible in its basic idea. “In the long run, the tramway is the greenest way to move people,” Rislakki sums up.
BREEAM environmental certification is applied for Crown Bridges, and responsibility goals are reflected in all decision-making. For example, efforts are made to recycle soil and building materials, such as curbs. The aim is also to keep the water cycle unchanged despite the construction. The permeability of the soil is taken care of, for example, by using green stones.
“The green tram structure of the route for rescue vehicles utilises new types of Ruimukivi green stones,” Putkonen says. In the holes of the stones grows lawn. “With the project, we have developed the substructure of the greenstones to ensure that it can withstand the future traffic load.”
Railway technology takes weather conditions and climate risks into account
The design of a new tramway line requires the cooperation of many types of technology. The most challenging places for railway and railway electrical engineering can be found on the 1200-metre-long Kruunuvuori Bridge.
“The design of rail exercise equipment prepares for the large thermal expansion of the structures of Finland’s longest bridge,” Utti says. The suspension structures of contact wires, on the other hand, emphasise marine wind loads. “We use sturdy poles and swing perches, as well as a large number of rope portals. They keep the contact wires in place even in storm winds.”
The operation of electricity supply stations has also been ensured as the climate changes. The basements have pumping stations for stormwater flooding, and sea floods have been taken into account in the street construction of the tracks. New types of solutions are also used to prepare for winter conditions.
“Ice can accumulate on tram overhead contact lines and the trams do not receive electricity, so this is the first time that trams in Helsinki are testing heated contact wires,” Utti says. However, he thinks there is one thing above all others in a functional whole. “Highly automated gear control is the nerve centre of the tramway system. It keeps both old trams and new light rail on the right routes.”
The Crown Bridges alliance consists of the design offices Sweco Finland Oy, Ramboll Finland Oy and Sitowise Oy, and YIT Suomi Oy and NRC Group Finland Oy are responsible for the implementation.
Photo: Crown Bridges tramway