Historical clue formulations

• Freight train part — 2018-09-26
• Part of a freight train — 2011-12-05
• Six, at a 37-/40-Across — 2011-06-08
• It's in for the long haul — 2006-04-28
• Railyard sight — 2006-03-04
• Hobo's ride, perhaps — 2005-04-05
• Rail yard sight — 1999-05-06
• Freight carrier — 1994-12-29
• Train freight holder — 1994-12-06