▁cars ▁are ▁identified ▁extern ally ▁by ▁tw in ▁square ▁windows ▁at ▁the ▁center ▁of ▁the ▁cars , ▁where ▁the ▁air ▁int ake ▁du ct work ▁( to ▁the ▁ro o ft op ) ▁for ▁the ▁generator ▁was ▁located . ▁ ▁Sh or el iner ▁III ▁ ▁Sh or el iner ▁II Is ▁date ▁from ▁ 1 9 9 1 ; ▁ 4 9 ▁cars ▁were ▁built . ▁This ▁series ▁is ▁based ▁on ▁New ▁Jersey ▁Trans it ' s ▁Com et ▁III . ▁The ▁main ▁differences ▁between ▁this ▁series ▁and ▁previous ▁ones ▁are ▁an ▁added ▁center ▁door ▁and ▁the ▁rest room ▁is ▁located ▁at ▁the ▁center ▁of ▁the ▁cars ▁that ▁are ▁so ▁equ ipped ▁instead ▁of ▁the ▁end . ▁ ▁Sh or el iner ▁IV ▁ ▁The ▁Sh or el iner ▁IV ▁is ▁much ▁like ▁the ▁Sh or el iner ▁III ▁but ▁the ▁engine ers ▁side ▁door ▁has ▁been ▁removed ▁as ▁a ▁safety ▁measure . ▁Based ▁on ▁the ▁N J ▁Trans it ▁Com et ▁IV , ▁they ▁were ▁built ▁in ▁two ▁distinct ▁groups ▁between ▁ 1 9 9 6 ▁and ▁ 1 9 9 8 . ▁The ▁first ▁order , ▁from ▁ 1 9 9 6 – 9 7 , ▁consisted ▁of ▁ 5 0 ▁cars . ▁The ▁second ▁set , ▁built ▁for ▁Connecticut ▁D OT ▁in ▁ 1 9 9 8 , ▁consisted ▁of ▁ 1 0 ▁cars . ▁This ▁gives ▁a ▁total ▁count ▁for ▁the ▁order ▁of ▁ 6 0 ▁cars . ▁ ▁Car ▁names ▁ ▁Many ▁of ▁Sh or el iner