Kandovan Tunnel
The Kandovan Tunnel, officially 11th Tunnel, is a major road tunnel on Chalus Road, Iran. The tunnel crosses Alborz, connecting Alborz province to Mazandaran province. It was completed in 1938 as one of the first tunnels in Iran in order to make the route from Tehran to Caspian Sea passable in harsh winter times.
History
Before the construction of the Kandovan Tunnel, travelling from Tehran to Mazandaran in this section of the Alborz Range was usually impossible in wintertime and early spring. In 1864, by the commission of Naser al-Din Shah Qajar, Austrian engineer Albert Joseph Gasteiger built a paved road from Marzanabad to Gach Sar, but the Kandovan Pass, the highest point of that road, remained difficult for travel.After the invention of automobiles, the demand for a road suitable for vehicles with rubber tires grew. In 1935, by the commission of Reza Shah, the existing road was ordered to be widened and repaved, and a new tunnel that could cross the Kandovan Pass was built. On 17 May 1938, the new tunnel was officially opened in the presence of the Pahlavi king and his young crown prince. The tunnel formed part of the Tehran-Caspian highway linking Tehran to Alborz. The construction cost was 24,853,400 Rials.
Renovation
The Kandovan Tunnel was not built to be sufficiently wide and high for the safe passage of two automobiles or tall trucks traveling at high speed. Two police officers had to stand at either end of the tunnel, guiding drivers by letting them inside in groups, and stopping traffic from the opposite side. After half a century the population of Iran had doubled and transit through the Kandovan Tunnel became a major challenge.In 1995, by the commission of the government of Akbar Hashemi Rafsanjani, addressing the problem began. The project soon became a challenge itself, since the moist and weak soil made the tunnel collapse many times during its construction. After seven years, renovation was finished.