▁employed ▁third - ra il ▁elect r ification . ▁So ▁that ▁the ▁C & SL ▁became , ▁in ▁addition , ▁the ▁first ▁major ▁railway ▁in ▁the ▁world ▁to ▁use ▁electric ▁tra ction . ▁ ▁Foot ▁tunnel ▁ ▁The ▁rail car ▁and ▁steam ▁engines ▁were ▁removed , ▁gas light s ▁installed ▁and ▁the ▁passenger ▁lif ts ▁replaced ▁with ▁spir al ▁st air cases . ▁The ▁tunnel ▁opened ▁to ▁ped est ri ans ▁at ▁a ▁to ll ▁of ▁d ▁and ▁became ▁a ▁popular ▁way ▁to ▁cross ▁the ▁river , ▁aver aging ▁ 2 0 , 0 0 0 ▁people ▁a ▁week ▁( one ▁million ▁a ▁year ). ▁Its ▁main ▁users ▁were ▁described ▁as ▁" the ▁working ▁classes ▁who ▁were ▁formerly ▁entirely ▁dependent ▁on ▁the ▁fer ries ". ▁In ▁September ▁ 1 8 8 8 ▁the ▁sub way ▁briefly ▁achieved ▁not or iety ▁after ▁a ▁man ▁with ▁a ▁kn ife ▁was ▁seen ▁in ▁the ▁tunnel ▁at ▁the ▁time ▁when ▁Jack ▁the ▁Ri pper ▁was ▁comm itting ▁mur ders ▁in ▁nearby ▁White ch ap el . ▁ ▁In ▁his ▁Dictionary ▁of ▁London , ▁Charles ▁Dick ens ▁Jr ▁commented ▁on ▁the ▁small ness ▁of ▁the ▁tunnel : ▁" there ▁is ▁not ▁much ▁head - room ▁left , ▁and ▁it ▁is ▁not ▁advis able ▁for ▁any ▁but ▁the ▁very ▁brief est ▁of ▁Her ▁Majesty ' s ▁lie ges ▁to ▁attempt ▁the ▁passage ▁in ▁high - he e led ▁bo ots , ▁or ▁with ▁a ▁hat ▁to ▁which ▁he ▁attach es ▁any ▁particular ▁value ." ▁ ▁The ▁Italian ▁writer ▁Ed