The Bukovo Tunnel

Initially there were no plans for a tunnel at Bukovo. It was built because the slope that the railroad line needed to cross was unstable and thus unsuitable for construction. However, ground conditions were also unfavorable for tunneling. Strong earth pressure repeatedly caused the ceiling of the excavated shaft to collapse and work was constantly interrupted. In October 1905, just before the planned opening of the railroad line, a large part of the excavated shaft collapsed again; engineers considered completely abandoning the tunnel and finding a new and more favorable route. Nonetheless, they persevered and in June 1906 the first steam engine was able to travel through this section of the line as well.

However, this was not the end of the problems. Poor ventilation made the Bukovo Tunnel a nightmare for all train personnel on this route. The steep slope required up to three steam engines for heavy freight trains, and train staff often fainted from lack of oxygen. In 1914, a ventilation system was built on the tunnel's northern side. Air was supplied to the tunnel through a large concrete tube, increasing the tunnel's length to 937 meters.