Answer:

flatcar

AnswerCrossword Clue
FLATCARSideless carrier
FLATCARIt has no sides or roof
FLATCARFreight train component
FLATCARPart of a train
FLATCARFreight-train unit
FLATCARA caboose preceder
FLATCARPart of a freight train
FLATCARRolling freight transporter
FLATCARFreight carrier
FLATCARFreight train unit
FLATCARRoller without sides
FLATCARPart of many a freight train
FLATCARIt might be filled with felled timber
FLATCARFreight bearer
FLATCARPiggybacking spot