The design provides for construction of a combined motorway and railway tunnel system crossing the Lena River, the largest river in the North-Eastern Siberia. The designers have developed a design case for a tunnel crossing between Nizhni Bestyakh and Yakutsk. The tunnel will link the capital city of the largest Russian region to the railway and highway systems of the country and will ensure steady eastbound and southbound freight and passenger traffic.
Yakutsk is connected to the outside world only by a ferry in summer and by the ice cover road in winter. The ferry cannot be used to cross the river in spring and in autumn because of ice drift and freeze-up, respectively.
The underground Lena crossing per design is a tunnel system comprised of a single-track 10-meters diameter railway tunnel and 13-meters diameter two-lane motorway tunnel. The full length of the tunnel crossing will be 8,347 meters, and the construction time is 59 months.
Designing the Lena River transportation crossing has a 30-years history, but all design cases have been built around a bridge so far. The analyses show that the tunnel case will have a lesser environmental impact compared to the bridge case; the tunnels do not impose navigation restrictions; they rule out ice blockage, reduce the construction and operation cost, and ensure higher reliability.