The superstructures contract for the rails of the Matinkylä–Kivenlahti section of the West Metro project has begun. The contract covers the laying of ballast, and the installation of cable ducts, sleepers, rails and the conductor rail. Once this work is completed, test runs of the metro train will be conducted on the new section in summer 2021. The first rails have already arrived at Matinkylä and are awaiting installation.
2020 will be an intense year of construction for the Matinkylä–Kivenlahti metro section. The focus of construction shifted in the spring from structural work to surfaces and interiors, HVAC and electricity and automation installations. All five metro stations as well as the rail line have several contracts under way and an increasing number of operators working on them. The Sammalvuori depot has already progressed to the testing phase. The depot will be completed this year. Overall, the project is proceeding in line with the project plan’s schedule and budget.
“The superstructures contract for the rail tunnels will begin with the laying of sub-ballast. The total length of the rail tunnel is 17.5 kilometres. The ballast will be brought into the tunnel in dump trucks: one load of ballast will cover approximately five metres of track. Noise insulation will be installed underneath the layer of ballast in both tunnels to ensure that structure-borne noise does not carry to the buildings above,” says Juha-Matti Pakka, supervisor of the rail engineering contracts on the West Metro project.
The next stage will see the switches installed in the tunnel; these will be measured and adjusted multiple times during the contract. Retaining wall elements, the top of which serves as an emergency exit route and the inside of which contains the technology required for a modern metro system, have already been installed in the tunnels as part of an earlier contract. The retaining wall’s cable ducts will be installed in conjunction with the levelling of the ballast.
The next step will be to install the sleepers in the tunnel. The section will have a total of 27,400 sleepers, supplied by Parma’s Forssa factory. The rails to be installed on the sleepers will arrive from Spain and will be welded into 120-metre lengths at Vossloh’s Kaipiainen factory. The rails will be delivered during the night via the Vuosaari harbour, through the current metro line to Matinkylä, and from there to the new section. The rails for the work track are already at Matinkylä, awaiting installation west of Matinkylä.
After the rails are installed, the track ballast will be laid using a ballast spreader that was specially made for the contract. Track ballast is laid in between the sleepers.
“After the track ballast is levelled out, the rail line will be supported and welded into a continuous track. Continuous track welding requires close monitoring and documentation of the rail’s temperature. This will ensure the smoothest and most consistent metro ride for future commuters,” says Pakka.
After the rail installation, a conductor rail will be affixed to the supports on every ninth sleeper. The conductor rail will be switched live in summer 2021, and thereafter test runs can begin.
The target schedule is to hand over the stations and rail line and their technical systems to the metro operator HKL in 2023. Länsimetro Oy will remain the owner and developer of the metro section.
Photos of phase II of the Matinkylä–Kivenlahti section of the track before the start of the superstructures contract.
The metro tunnel before the ballast, sleepers and rails: https://www.flickr.com/photos/lansimetro/47836508652/in/album-72157691717380110/
A connecting tunnel linking two parallel tunnels: https://www.flickr.com/photos/lansimetro/47836507962/
A map of the West Metro line Ruoholahti–Matinkylä and Matinkylä–Kivenlahti: https://www.flickr.com/photos/lansimetro/47675267201/
Photos of the stages of phase I of the Ruoholahti–Matinkylä superstructures contract:
Keilaniemi before the installation of the rails: https://www.flickr.com/photos/lansimetro/17054319838/in/album-72157665101958082/
Installation of the rails in phase I: https://www.flickr.com/photos/lansimetro/16568966245/in/album-72157665101958082/
The track from Ruoholahti westward, before the installation of the rails: https://www.flickr.com/photos/lansimetro/15029531393/in/album-72157648603263418