Brütten Tunnel Zürich–Winterthur: groundbreaking planned for July 2026

The roughly 9 km, twin-bore Brütten Tunnel (two tubes of 10 m diameter, 20 cross-passages) is the centerpiece of the four-track expansion between Zurich and Winterthur, intended to raise line capacity from 670 to 900 trains per day. Switzerland's Federal Administrative Court discontinued the remaining appeal proceedings in January 2026, groundbreaking is planned for July 2026, and actual tunnel boring with TBMs is scheduled to start in 2029. Total costs are estimated at CHF 3.27 billion, with full commissioning expected by the end of 2037 according to the source (differing from the 2035 date given in the original list). Update (2 Jul 2026): With the official groundbreaking in Bassersdorf on 2 July 2026 (Federal Councillor Rösti, Zurich cantonal councillor Neukom, SBB CEO Ducrot), construction of the Zurich–Winterthur four-track expansion has begun; SBB puts the cost at about CHF 3.3 billion (accuracy ±10 per cent), financed through the Rail Infrastructure Fund. The sub-projects enter service in stages (delays are possible): Winterthur Töss at the end of 2028, Bassersdorf in summer 2030, Dietlikon in summer 2032, Wallisellen at the end of 2032 and the 9-kilometre Brütten tunnel (boring from 2029) in 2037 according to current planning. Capacity between Zurich and Winterthur is to rise by 30 per cent to about 900 trains a day; SBB expects a construction period of around ten years. (LOK Report, 2 Jul 2026)