▁of ▁the ▁Regional ▁Fast ▁Rail ▁project . ▁The ▁sub urban ▁network ▁and ▁bus ier ▁regional ▁lines ▁use ▁variants ▁of ▁Autom atic ▁Block ▁Sign alling , ▁while ▁qui eter ▁lines ▁use ▁the ▁Train ▁Staff ▁and ▁T icket ▁or ▁Train ▁Order ▁systems ▁of ▁saf ew ork ing . ▁Train ▁protection ▁has ▁also ▁progress ed , ▁with ▁the ▁Train ▁Prote ction ▁& ▁Warning ▁System ▁also ▁introduced ▁on ▁major ▁passenger ▁lines ▁as ▁part ▁of ▁the ▁Regional ▁Fast ▁Rail ▁project . ▁ ▁Rol ling stock ▁Rol ling stock ▁in ▁Victoria ▁has ▁used ▁air ▁bra king ▁since ▁tests ▁of ▁continuous ▁train ▁bra kes ▁were ▁carried ▁out ▁in ▁ 1 8 8 4 . ▁Initial ly ▁sc rew ▁cou pl ings ▁were ▁used ▁to ▁connect ▁w ag ons , ▁but ▁from ▁ 1 9 2 4 ▁automatic ▁kn uck le ▁cou pl ers ▁were ▁introduced , ▁with ▁buff ers ▁removed ▁from ▁fre ight ▁w ag ons ▁by ▁ 1 9 6 0 . ▁ ▁Lo comot ives ▁ ▁In ▁Victoria ▁groups ▁of ▁locomot ives ▁of ▁the ▁same ▁design ▁are ▁class ed ▁together ▁by ▁letter , ▁in ▁a ▁system ▁introduced ▁in ▁ 1 8 8 6 . ▁Initial ly ▁low ▁letters ▁were ▁given ▁to ▁passenger ▁classes , ▁and ▁high ▁letters ▁for ▁goods ▁classes , ▁but ▁from ▁about ▁ 1 9 1 6 ▁this ▁pattern ▁was ▁disc arded . ▁Within ▁classes ▁locomot ives ▁are ▁individually ▁number ed , ▁in ▁a ▁continuous ▁number ▁block ▁which ▁is ▁unique ▁to ▁the ▁class . ▁In ▁some ▁cases ▁locomot ives ▁have ▁been ▁ren umber ed ▁to ▁keep