The maintenance and storage depot for the metro system is at Roihupelto, between the stations of Siilitie and Itäkeskus.
The depot is connected to the metro line from both the east and western directions, with a third platform at Itäkeskus used for alighting passengers before returning to the depot.
Both heated and unheated undercover storage areas are provided so that trains are ready for use without a lengthy heating period.

Behind the Roihupelto depot is the metro test track, allowing testing at speeds of up to 100 km/h; the far end of this test-track was connected via a non-electrified 5 km long railway route to the VR main line at Oulunkylä railway station.
Both the metro and mainline share a 1,524 mm (5 ft) track gauge.
The old access line was mostly along the first half of the old Herttoniemi Harbour railway.
Through the area of Viikki, this single line had street running.
The Jokeri bus-line makes use of the depot line's railway bridges to cross Vantaa river and Finnish national road 4.

In 2012 the old depot link was closed and partially removed when a new 2 km metro link line was built from the then present end at Vuosaari metro station, to the VR harbour railway in the new Vuosaari harbour.
The old link line will be rebuilt for the light rail-based Jokeri line upgrade, scheduled for 2016 onwards.
The maintenance and storage depot for the metro system is at Roihupelto, between the stations of Siilitie and Itäkeskus. The depot is connected to the metro line from both the east and western directions, with a third platform at Itäkeskus used for alighting passengers before returning to the depot. Both heated and unheated undercover storage areas are provided so that trains are ready for use without a lengthy heating period.
Behind the Roihupelto depot is the metro test track, allowing testing at speeds of up to 100 km/h; the far end of this test-track was connected via a non-electrified 5 km long railway route to the VR main line at Oulunkylä railway station. Both the metro and mainline share a 1,524 mm (5 ft) track gauge. The old access line was mostly along the first half of the old Herttoniemi Harbour railway. Through the area of Viikki, this single line had street running. The Jokeri bus-line makes use of the depot line's railway bridges to cross Vantaa river and Finnish national road 4.
In 2012 the old depot link was closed and partially removed when a new 2 km metro link line was built from the then present end at Vuosaari metro station, to the VR harbour railway in the new Vuosaari harbour. The old link line will be rebuilt for the light rail-based Jokeri line upgrade, scheduled for 2016 onwards.
Helsinki Metro