▁of ▁one ▁tra iler ▁and ▁ren umber ed ▁as ▁ 5 0 8 / 1 . ▁The ▁individual ▁passenger ▁door ▁controls ▁were ▁pl ated ▁over ▁before ▁they ▁were ▁sent ▁north . ▁The ▁spare ▁tra iler ▁car ▁from ▁each ▁set ▁was ▁incorpor ated ▁into ▁class ▁ 4 5 5 / 7 ▁EM Us . ▁Car riage ▁number ing ▁is ▁as ▁follows : ▁ 6 4 6 4 9 - 6 4 6 9 1 ▁- ▁D MS O ▁ 7 1 4 8 3 - 7 1 5 2 5 ▁- ▁T SO ▁ 7 1 5 2 6 – 7 1 5 6 8 ▁– ▁T SO ▁( rem oved ▁before ▁transfer ▁to ▁Mer se ys ide ) ▁ 6 4 6 9 2 - 6 4 7 3 4 ▁- ▁B D MS O ▁ ▁Current ▁operations ▁ ▁Mer sey ra il ▁ ▁Mer sey ra il ▁oper ates ▁ 2 7 ▁ 5 0 8 s , ▁which ▁are ▁used ▁inter change ably ▁between ▁the ▁Northern ▁Line ▁and ▁the ▁Wir ral ▁Line . ▁They ▁commonly ▁work ▁the ▁following ▁services : ▁South port ▁- ▁Hun ts ▁Cross ▁line ▁Liverpool ▁Central ▁- ▁Or m sk irk ▁line ▁Liverpool ▁Central ▁- ▁Kirk by ▁line ▁Liverpool ▁L ime ▁Street ▁- ▁New ▁Bright on ▁line ▁Liverpool ▁L ime ▁Street ▁- ▁West ▁Kir by ▁line ▁Liverpool ▁L ime ▁Street ▁- ▁Ch ester ▁line ▁Liverpool ▁L ime ▁Street ▁- ▁Ell es m ere ▁Port ▁line ▁ ▁Mer sey ra il ' s ▁fleet ▁of ▁Class ▁ 5 0