Железнодорожный тоннель БАМа длиной 15 343 м под Северо-Муйским хребтом — самый длинный в России. Строительство, начатое в 1977 году, велось с двух порталов и через вертикальный ствол в сложных гидрогеологических условиях; сквозное движение открыто в 2003 году. Включает основной однопутный тоннель и служебную штольню.
A railway tunnel of the Baikal–Amur Mainline (BAM) measuring 15,343 m beneath the Severomuysky Range — the longest in Russia. Construction, begun in 1977, was carried out from two portals and through a vertical shaft under difficult hydrogeological conditions; through traffic opened in 2003. It comprises the main single-track tunnel and a service adit.
345 200 000 руб., в ценах 1969 г.
The TASS special project on the tunnel's construction (spec.tass.ru) explicitly states «345,2 млн рублей — сметная стоимость Северомуйского тоннеля в ценах 1969 года» — this is the official design-stage estimate at project inception. A secondary encyclopaedic source (ruxpert.ru) also states a total completion cost of approximately 16 billion rubles in 2003 prices, reflecting the full 26-year build-out including cost overruns and post-Soviet financing. Several popular sources (fb.ru, architectureguru.ru) cite ~9 billion rubles without specifying a price year. The 345.2 million figure in 1969 prices is chosen as the primary documented value because it is cited with an explicit price base by a credible news organisation (TASS).