Penmanshiel Tunnel
...that during engineering work in 1979, the collapse of the Penmanshiel Tunnel severed the main railway line between London and Edinburgh for five months?
...that during engineering work in 1979, the collapse of the <b id="mwCR8"><a href="./Penmanshiel_Tunnel" id="mwCSA" rel="mw:WikiLink" title="Penmanshiel Tunnel">Penmanshiel Tunnel</a></b> severed the <a href="./East_Coast_Main_Line" id="mwCSE" rel="mw:WikiLink" title="East Coast Main Line">main railway line</a> between <a href="./London" id="mwCSI" rel="mw:WikiLink" title="London">London</a> and <a href="./Edinburgh" id="mwCSM" rel="mw:WikiLink" title="Edinburgh">Edinburgh</a> for five months?