 Stations can be double-span with a single row of columns, triple-span with two rows of columns, or multi-span.The typical shallow column station in Russia is triple-span, assembled from concrete and steel, and is from 102 to 164 metres in length with a column spacing of 4-6 m. Along with the typical stations, there are also specially built stations.For example, one of the spans may be replaced with a monolithic vault (as in the Moskovskaya station of the Samara Metro or Sibirskaya of the Novosibirsk Metro).