Preliminary work on the tunnel started in 1975, with tunneling commencing on 28 May 1977. The tunnel was built through very difficult rock with four major faults and a great deal of underground water, some at pressure. One method used was to pump liquid nitrogen into the rock, freezing the water until the cut could be sealed. In September 1979 workers broke into a fault connected to a underground lake. This required building a drainage tunnel and delayed work for 18 months. When it became clear that the tunnel would not be completed in time for the planned official opening of the BAM in 1984, a bypass was built during the years 1982–83. This had a 4%
grade and traffic was limited to . Passenger traffic was prohibited. In 1989, a new bypass of was completed (with a 2% ruling grade) and the original bypass route was closed. The two bypasses crossed near the Pereval Station; the new bypass route has lengthy extra loops at both ends of its route to enable its construction with reduced gradient. Once the new bypass was opened, the older one (used mainly for transporting goods required for construction) was dismantled and now almost nothing remains of it. From 1989, the new route was open for passenger trains, although it required auxiliary engines to push trains up steep sections and was limited to a maximum speed of , the route taking around 2 hours to cross. This section features a large number of tight curves and viaducts, with the long curved bridge built near the tunnel's western portal being nicknamed locally the Devil's Bridge (Chortov Most ). It also includes two tunnels of its own, one of which is in length. It is expensive to maintain and is at risk from
avalanches. The main tunnel was put into operation on 5 December 2003 (signed off on 30 November), with yet another announcement of the completion of the BAM project. During the
Russo-Ukrainian War, on 30 November 2023, Ukrainian media reported that four explosive devices exploded in the tunnel during the movement of a freight train composed of 41
tank cars carrying diesel fuel plus three cars carrying aviation fuel. A fire in the tunnel was also reported by Russian media. The
Security Service of Ukraine claimed to be behind the incident. With the tunnel out of commission, Russia redirected traffic to the bypass. The next day (1 December), the Security Service of Ukraine claimed to have caused a train with fuel cars to explode while crossing the Devil's Bridge on the 1989 bypass. The tunnel was reopened on 2 December. ==Current status==