The Norfolk and Western Quad Hopper Car No. 6446-25 was produced from 1955 until 1957, and again in 1963. The car shows the number "644625" and "NEW 6-54" on the sides and came with hatch covers. The early production would have bar-end trucks that came both with, and without tabs, while the last edition came with AAR trucks equipped with disc couplers. There are five variations:

Variation A: BLACK painted car with WHITE lettering without center brace holes on the car sides. Came in a box that was lettered "6446 CEMENT CAR / 25 LIONEL 25" on the end.
Variation B: Same as Variation A, except with center brace holes and center brace.
Variation C: GRAY body with BLACK lettering and no center brace holes on the sides.
Variation D: Same as Variation C, except with center brace holes and center brace.
Variation E: GRAY unpainted plastic body with BLACK lettering. This variation has the center brace holes, but no brace. It has AAR trucks with disc couplers, and came in a box marked "6446 CEMENT CAR" on the ends that was included with set No. 13098 in 1963. This is the most difficult version to find especially with the box.