▁ 1 8 5 1 ▁the ▁Ts ar ist ▁Government ▁of ▁Russia ▁made ▁a ▁decision ▁to ▁build ▁the ▁Saint ▁Petersburg ▁– ▁Wars aw ▁railway ▁line ▁with ▁a ▁length ▁of ▁approximately ▁ 1 , 2 5 0 ▁kilometres . ▁It ▁was ▁built ▁to ▁Russian ▁gauge . ▁Starting ▁from ▁ 1 8 5 8 ▁the ▁Wars aw ▁– ▁Saint ▁Petersburg ▁Railway ▁line ▁connecting ▁Saint ▁Petersburg ▁and ▁Wars aw ▁was ▁being ▁built ▁quite ▁intens ively . ▁The ▁government ▁of ▁Pr uss ia ▁addressed ▁Russia ▁asking ▁permission ▁to ▁start ▁building ▁a ▁railway ▁from ▁Vir bal is , ▁which ▁was ▁situated ▁near ▁its ▁border , ▁towards ▁L ent var is ▁through ▁Ka unas . ▁However , ▁the ▁terrain ▁around ▁Ka unas ' ▁centre ▁is ▁h illy ▁and ▁unf avor able ▁for ▁the ▁direct ▁rail ▁passage . ▁The ▁main ▁and ▁most ▁complicated ▁objects ▁were ▁the ▁tunnel ▁and ▁largest ▁in ▁Lith u ania ▁railway ▁bridge ▁over ▁the ▁Nem unas ▁river . ▁The ▁construction ▁of ▁the ▁tunnel ▁started ▁on ▁ 1 5 ▁May ▁ 1 8 5 9 , ▁whereas ▁the ▁construction ▁of ▁the ▁bridge ▁started ▁a ▁bit ▁earlier ▁– ▁at ▁the ▁end ▁of ▁April , ▁ 1 8 5 9 . ▁The ▁railway ▁from ▁Vir bal is ▁to ▁Ka unas ▁was ▁also ▁being ▁built . ▁ ▁Const ruction ▁Ka unas ▁railway ▁tunnel ▁was ▁built ▁from ▁ 1 8 5 9 ▁till ▁ 1 8 6 1 . ▁The ▁construction ▁was ▁survey ed ▁by ▁the ▁French ▁engineer ▁G . ▁F . ▁Per rot , ▁as ▁well ▁as ▁Polish - L ith