Construction work on the Sammalvuori depot has started – the consortium behind the excavation continues its work into the construction phase

Construction work on the Sammalvuori metro depot of the Länsimetro Matinkylä-Kivenlahti section has begun. Two underground halls are going to be built in the depot – one for the night-time storage of metro trains and the other for maintenance facilities. Technical facilities are also being built at the northern end of the maintenance hall.

There is currently only one metro depot in Finland – the Helsinki metro depot in Myllypuro. However, Länsimetro’s Sammalvuori depot differs from the solutions at the Myllypuro depot.

“The depot is being built completely inside bedrock. The depot commission includes excavation and construction work, as well as planning for the entire depot. This is an exceptional mode of operation and form of cooperation compared to Länsimetro’s previous contracts, and it requires new ways of thinking and close cooperation between all parties, which has already provided plenty of positive experiences during the excavation phase,” says Ulla Valtonen, Life Cycle and Risk Manager and Sammalvuori Depot Real Estate Development Manager from Länsimetro Oy.

The Sammalvuori excavation and construction consortium consists of Kalliorakennus-Yhtiöt Oy, EM Pekkinen Oy, Konevuori Oy and Aro-Systems Oy.

E.M. Pekkinen Oy is implementing the work carried out after the excavation, such as pipework, sewerage, bearing courses, access tunnel entrance structures and buildings constructed in the upper parts of the three shafts.

“We have previously carried out Länsimetro civil engineering works in Kivenlahti and Lauttasaari. It’s nice to be involved in projects like this one,” says Juha Tuppurainen, Construction Manager at E.M. Pekkinen Oy.

Kalliorakennus-Yhtiöt Oy is involved in the construction project in the implementation of for example, concrete structures for the depot and all fixed structures, such as station platforms, shafts, stairs and lifts.

“This is an interesting challenge and this new form of cooperation has worked well,” says Jukka Halonen, Managing Director of Kalliorakennus-Yhtiöt Oy.

Aro Systems Oy is responsible for the building services of the depot, including design and implementation of HVAC and electric systems.

“The systems that will be built, such as smoke extraction, lighting and heating, are familiar to us, but the conditions and operating environment are new. An interesting project on the whole,” says Simo Helskä, Building Services Project Manager of Aro Systems Oy.

Further information: 

Ulla Valtonen, Life Cycle and Risk Manager, Sammalvuori Depot Real Estate Development Manager: +358 (0)50 301 4761, ulla.valtonen(at)

Jukka Halonen, Managing Director, Kalliorakennus-Yhtiöt Oy: +358 (0)400 201 981, jukka.halonen(at)

Juha Tuppurainen, Construction Manager, E.M. Pekkinen Oy: +358 (0)400 448 842, juha.tuppurainen(at)

Simo Helskä, Building Services Project Manager, Aro Systems Oy: +358 (0)10 8356 229, simo.helska(at)