Ring Rail Line to Helsinki-Vantaa Airport will be delayed by at least six months
Glycol leaks are being plugged up at the construction site of the tunnel under the Helsinki-Vantaa Airport area
It is an ill wind that blows nobody any good. Taxi entrepreneurs in Vantaa will probably be somewhat relieved, but arriving and departing air passengers not so much.
News has come that the construction work on the new Ring Rail Line to Helsinki-Vantaa Airport is likely to be delayed by at least six months. Initially, the rail link was scheduled to open in 2014, but now passenger traffic is estimated to begin in the summer of 2015 at the earliest.
The reason for the delay is the fact that in connection with the excavation work in the Ring Rail Line tunnel, water containing glycol and its breakdown products was seeping into the soil underneath the airport area (see earlier stories). Glycol is used to de-ice airplanes.
The breakdown products of glycol shorten the operating life of concrete and steel structures, which has led to unusually sturdy construction solutions being required.
The leaks were discovered in connection with the excavation work of the tunnel already some two years ago. Since then attempts have been made to resolve the problem in many ways.
In order to reinforce the airport station tunnel, an airtight twin tunnel sheath is being built inside the bedrock tunnel. The twin tunnel will be about one kilometre long.
Similar insulation structures will also have to be used in the station premises, vertical shafts, and pedestrian tunnels. The odour caused by the breakdown products will be removed by underpressuring the space between the bedrock and the insulation structure.
Elsewhere the construction work of the Ring Rail Line has proceeded on schedule. The construction work on the above-ground rail line between the Outer Ring Road and the motorway to Hämeenlinna and Tampere will be completed in August 2013. The next work to be completed will be the Vantaakoski Station.
In addition to the planned five stations, there will be reservations for three additional stops to be added later. Options for tunnel stations will be put in place at Ruskeasanta and Viinikkala, while a reservation for a later above-ground station will be built at Petas.
The Ring Rail Line will be an 18-km extension to existing commuter tracks, connecting the final stop of the Vantaankoski commuter train line with the airport, from where it continues on to connect with the main north-south railway route of Helsinki-Tampere-Oulu (see map).
At the moment, the project is employing approximately 630 people.
The estimated cost of the venture is EUR 655 million, which will be shared between the Finnish Transport Agency, who are building the tunnel, the City of Vantaa, and the aviation authority Finavia, who are in charge of the running of the airport. Something of an unseemly row broke out over who was to foot the bill for the additional cost caused by the glycol problem.
The Ring Rail Line will be a 18-kilometre circular rail route, of which some eight kilometres will run through tunnels under the airport area.
In the first phase there will be five new stations at Kivistö, Aviapolis, Helsinki-Vantaa International Airport, Leinelä, and Vehkala.
The Ring Rail Line will use new Sm5 low-floor commuter trains known as FLIRT (Fast Light Innovative Regional Trains).
Trains will run at 10-minute intervals in both directions. The top speed on the line will be 120 km/h.
Previously in HS International Edition:
New glycol leaks discovered at Helsinki-Vantaa tunnel construction site (10.5.2012)
Going up: Latest estimate for glycol damage bill for airport rail tunnel now stands at EUR 45 million (16.3.2012)
New Ring Rail Line to connect Helsinki-Vantaa Airport to centre of Helsinki (15.2.2008)
Hefty row brewing over increased construction costs of rail tunnel under Helsinki-Vantaa Airport (13.12.2011)
Microbe population in tunnel brings construction of new Ring Rail Line to a juddering halt (1.10.2010)
Ring Rail Line (Wikipedia)
Finnish Transport Agency: Ring Rail Line