Whatever happened to........

[nscnotp1]

Here is something I was thinking about while surfing the internet;

Whatever happened to those "pig" cars with a single wheel on each end of the car?

I haven't seen any of them lately. Anyone out there have a clue??

[Hoydie17]

You're talking about the FRONT RUNNERS

FRA banned them back in the 90's for safety reasons. 

I understand empty cars had a nasty habit of jumping the rails if they were in the middle of the train and the slack came in.   Empty cars on the end of a train did something called "Hunting" which is the flanges would move laterally on the rails and wore out very quickly resulting in derailments. 

[Hoss Cat]

Its called hunting.

[Backyard]

  ...and, they the cars, desighned in France, had a tare weight of 26,000lb!
And...so...as railroad practice, if you'll remember, they could be found anywhere in the movement.