Suomenlinna Tunnel7.05.2008 at 15:49 | Posted in Architecture, History, Industrial, NotBeen but WannaGo, Strange | 7 Comments
Tags: helsinki, suomenlinna, tunnel
Although it is by no means a secret not everyone knows there’s a tunnel connection from the Suomenlinna island to mainland Helsinki. The 1300 metre long tunnel starts in northern Länsi-Mustasaari island and comes out in south-eastern Kaivopuisto by the Läntinen Puistotie street. Apart from providing the islands with hot water the tunnel serves as an emergency route for ambulances, fire brigade and police. The tunnel is nested 63 metres below sea level half of which is rock and half water. About 500 cubic metres of seawater seep into the tunnel every day and have to be constantly pumped out.
The Suomenlinna tunnel is only one of very many underground passages drilled in the rock underneath Helsinki. There are public transport tunnels like the metro tunnel from Sörnäinen to Ruoholahti, there are numerous sewage tunnels and there is also a system of tunnels connecting Helsinki’s central hospitals that can be used to transport soldiers and medical equipment. The water in Helsinki is brought from the Päijänne lake by means of a 120km long tunnel dug 10-100m deep in the rock.