▁ ▁N AL X ▁- ▁N al co ▁Chem ical ▁Company ; ▁NASA ▁Rail road ▁ ▁N AL Z ▁- ▁Ne pt une ▁Orient ▁L ines , ▁Ltd . ▁ ▁N AM X ▁- ▁N AM X ▁Le asing ▁Company ▁ ▁N AP ▁ ▁- ▁Nar rag ans ett ▁Pier ▁Rail road ▁ ▁N AP X ▁- ▁North ▁American ▁Pl ast ics , ▁Inc . ▁ ▁N AR ▁ ▁- ▁Northern ▁Al berta ▁Railway ; ▁Canadian ▁National ▁Railway ▁ ▁N AR X ▁- ▁N OR CH EM ▁In cor por ated ▁ ▁NAS X ▁- ▁NASA ▁Rail road ▁ ▁NAT U ▁- ▁N asso ▁SA ▁ ▁NAT X ▁- ▁North ▁American ▁T ank ▁Line ; ▁North ▁American ▁Car ▁Cor p .; ▁General ▁Electric ▁Rail car ▁Services ▁Cor p .; ▁General ▁Electric ▁Rail ▁Services ▁Cor p . ▁ ▁NAT Z ▁- ▁North ▁American ▁Transport ation ▁ ▁NA UG ▁- ▁N aug at uck ▁Rail road ▁ ▁N AV E ▁- ▁N ava jo ▁Express ▁ ▁N B ▁▁ ▁- ▁North am pton ▁and ▁Bath ▁Rail road ; ▁Con ra il ▁ ▁N BC X ▁- ▁Neb r aska ▁Bo iler ▁Company ▁ ▁N B EC ▁- ▁New ▁Brun sw ick ▁East ▁Coast ▁Railway ▁ ▁N BER ▁- ▁N itt any ▁and ▁Bald ▁E agle ▁Rail road ▁ ▁N B IX ▁- ▁Bomb ard ier ▁Capital ▁Rail , ▁Inc . ▁ ▁N B NR ▁- ▁N ico let ▁Bad ger ▁Northern ▁Rail road ▁ ▁N BS R ▁- ▁New ▁Brun sw ick ▁Southern ▁Railway ▁