Hopes for construction of a Bering Strait Crossing in tunnel between north east Russia and North America are set to get a further boost from a conference to be hosted in October in the US state of Alaska, T&TI has been told.
The latest efforts to promote the major transport link between the continents took its first step in April, at a conference backed by an array of Russian federal industrial enterprises. At the event, president Putin chaired a workshop on rail development to 2030, a key project of which would be a 3500km link through Siberia to the Bering Strait.
Advocates of a tunnel across the Strait saw the strategic development plan for rail as giving new life to their dream. Under the auspices of a ‘TKM-World Link’ tag, they had organised the conference, the first ‘Megaprojects of the Russian Far East’ event. Having also drawn some US interest, the event is about to take its campaign for the tunnel link – which cost at least US$15bn, it admits – to Anchorage in Alaska, though the advocates also concede a great deal of site investigation and further feasibility designs are still needed, and little new was disclosed in terms of engineering.
The envisaged tunnel would be 113km long and pass under the Diomede Islands (Ratmanov and Krusenstern), on which shafts would be sunk for TBM drives of the tubes, anticipated to be two 9.5m diameter (excavated) running tunnels with a 5.5m diameter (excavated) service bore. Concept studies have also considered a twin-track, 11.8m diameter single bore for the running tunnel. The running and service tunnels would be spaced typically 23m-24m between centres.
Three caverns are planned in the scheme to act as safety complexes that can accommodate passenger train platforms and descending chambers for emergency isolation. Other key excavations include four shafts – two on the islands, 9km apart, and one each at the Russian and US coast which would be 37km and 44km, respectively, from the islands.
Geology along the proposed alignment is forecast to offer three-quarters of the tunnel length in good to favourable, whereas a quarter is satisfactory to poor, such as having fracture and partially unstable zones. At this stage, TKM-World Link describes the entire Siberia-Alaska rail connection as 6000km long, which could cost about US$65bn in total.
