▁tunnel ▁were ▁a ▁mix ▁of ▁elect r ified ▁and ▁non - elect r ified ; ▁the ▁B ury ▁Line , ▁from ▁Victoria , ▁used ▁a ▁unique , ▁ 1 2 0 0 ▁V ▁DC ▁third ▁rail ▁system ; ▁the ▁Bu xt on ▁line ▁was ▁une lect r ified , ▁while ▁the ▁St yal , ▁Cre we ▁and ▁Staff ord ▁lines ▁were ▁all ▁elect r ified ▁using ▁ 2 5 ▁k V ▁AC ▁from ▁overhead ▁w ires ▁( OH LE ). ▁The ▁proposal ▁would ▁have ▁seen ▁the ▁entire ▁planned ▁network ▁run ▁using ▁O H LE , ▁which ▁had ▁recently ▁been ▁fitted ▁to ▁the ▁West ▁Coast ▁Main ▁Line ▁as ▁far ▁as ▁Manchester ▁Pic c ad illy . ▁As ▁a ▁consequence ▁of ▁this , ▁new ▁rolling ▁stock ▁was ▁planned ▁to ▁operate ▁the ▁proposed ▁services . ▁ ▁P EP ▁rolling ▁stock ▁ ▁Because ▁of ▁the ▁requirements ▁of ▁operating ▁in ▁the ▁central ▁tunnel ▁section , ▁the ▁initial ▁SE L NE C ▁specification ▁for ▁new ▁trains ▁stated ▁that ▁they ▁would ▁require ▁both ▁sl iding ▁doors ▁and ▁end ▁connections , ▁which ▁did ▁not ▁feature ▁together ▁on ▁then ▁current ▁rolling ▁stock ▁operated ▁by ▁British ▁Rail . ▁The ▁initial ▁public ity ▁for ▁the ▁Pic c - V ic ▁plan , ▁which ▁was ▁described ▁as ▁" Man chester ' s ▁t ube ▁project ", ▁showed ▁an ▁artist ' s ▁impression ▁of ▁a ▁platform ▁with ▁a ▁train ▁res emb ling ▁the ▁ 1 9 6 7 ▁Stock , ▁as ▁used ▁on ▁the ▁Victoria ▁line ▁in ▁London . ▁However , ▁the ▁tw in ▁bore ▁t