Gimrinski highway tunnel
Gimrinski tunnel is the longest highway tunnel in the Russian Federation and countries of the former Soviet Union. Its length is 4,303 metres and it is surrounded by limestone at a depth of 850 metres; its diameter is 9 metres and the width of its carriageway is 7 metres.
The tunnel connects the town of Bujnaksk and village of Gimry. It also provides the shortest transportation link between 9 areas of mountainous Dagestan, the railway and the centre of the republic and it is not affected by weather conditions.
Construction has been conducted by SMU-55 in the harshest climate and geological conditions due to features of soil and the high pressure of underground water. SMU-55 had to use unorthodox construction technology and transportation methods for the materials since the traditional approach was impossible due to the higher than usual humidity and the extreme temperature conditions.
SMU-55 used some technological innovations that had been specifically devised by the construction bureau of the company for this object.