Construction of the West Metro’s first phase started in 2009. The excavation work was completed in 2014. Fifteen vertical shafts, nine rail switching halls and 54 connecting tunnels for two tunnels were built. Fifty-two different technical systems were installed, including automatic train control, safety automation, smoke detection systems and standby generators. Some 10,000 cubic metres of concrete was cast at each station. The platforms are 90 metres long and 12–16 metres wide. Technical systems at both ends of the platforms occupy approximately equal space on multiple floors. The image shows the size of Tapiola station in relation to Helsinki Olympic Stadium. The ventilation shafts are roughly the same height as the stadium’s tower. The metro station hall covers close to half of the stadium’s field. Eight stations and a total of 28 kilometres of rail line were built.
Completed metro will be more than what was specified in the project plan
If the first phase of the West Metro had been realised only to the extent laid down in the project plan, the costs would have amounted to an estimated EUR 933 million, and the cost overrun would have been altogether less than 10 per cent in relation to the index-adjusted project plan. Considered in relation to the project plan, and taking the risk reservation into account, the costs for West Metro do not substantially deviate from the planned costs.
As the construction progressed, the extent of the work carried out during phase one of West Metro changed considerably from what was specified in the project plan. The changes improved the metro, making it better suited to the changing urban structure, but they also affected the project’s overall costs. The overall cost forecast for the Ruoholahti–Matinkylä section is EUR 1,186 million. The forecast also includes projects to be implemented in the metro station’s surrounding environment, for instance, in Matinkylä. The index-adjusted budget for the construction project, to the extent laid down in the original project plan (2008), is EUR 849 million (project plan EUR 714 million + index adjustment EUR 135 million).
The areas required for technical spaces grew by even more than 50 per cent as a result of, for example, the need for more smoke-extraction ducts, and due to raising the technical facility systems from below the platforms to a higher position as a precaution against possible water damage. One decision that resulted in an important improvement for commuters was to make all entrances wheelchair accessible. Under the original project plan, only one wheelchair-accessible entrance was planned at every station. These improvements increased the metro stations’ construction costs and were among the biggest cost changes in the entire project.
Changing and developing the urban environment near the metro stations also had an impact on the project costs. For example, the size of the above-ground building at the Koivusaari metro station grew significantly to accommodate a second-floor entrance. The change was carried out to take into account the city’s plan to build a road between the metro building and the Länsiväylä highway.
Tests conducted to ensure the metro’s safety
Prior to commissioning phase one of the metro, tests and joint test runs were conducted to ensure that the metro would run as planned. The testing phase commenced in 2016 and continued until the beginning of regulatory authority inspections in the summer of 2017. At the beginning of September 2017, the stations and track were handed over to HKL, with the permission of the rescue departments, to be used for the preparation of the metro service. On 22 September, the building inspection authorities of Espoo and Helsinki granted permission to begin metro service on the west metro section. Länsimetro Oy handed over the stations and rail line to HKL on 3 October 2017. Eight stations and the rail line, including the technical systems for these, are under the ownership of Länsimetro Oy. HKL reports to Länsimetro Oy on the use of the rail line and stations and related service and maintenance tasks as agreed. Passenger traffic to Matinkylä began on 18 November 2017.
One of the key systems tested during joint test runs is the building technology supervision system. The building technology supervision system monitors the operations of other systems such as ventilation, access control, pumps, elevators, escalators, fire detectors and smoke detectors. The system monitors all equipment and systems that safeguard the safety and smooth running of the metro. All equipment was tested individually and its smooth operation was verified before it was tested jointly. The technical systems of the West Metro sections now form part of the current metro’s systems.
Excellent worksite safety
Special attention was paid to worksite safety during all construction stages of phase one of the West Metro. Considering the size and duration of the project, worksite safety was at an excellent level. A total of 34 rescue drills were organised in collaboration with the rescue departments. The drills included rescue operations in worksite conditions during building and excavation work.