Baikal-Amur Mainline

The Baikal-Amur Mainline (Russian Байкало-Амурская магистраль (БАМ), Baikalo-Amurskaya magistral’, BAM) is a 1,520 mm (4 ft 11 5⁄₆ in) broad gauge railway line in Russia. Traversing Eastern Siberia and the Russian Far East, the 4,324 km (2,687 mi) long BAM runs about 610 to 770 km (380 to 480 miles) north of and parallel to the Trans-Siberian railway.

The BAM was built as a strategic alternative route to the Trans-Siberian Railway, especially along the vulnerable sections close to the border with China. The BAM's costs were estimated at $14 billion, and it was built with special, durable tracks since much of it was built over permafrost. Due to the severe terrain, weather, length and cost Soviet premier Leonid Brezhnev described BAM as "the construction project of the century."