Mystery rolling stock

[AT41B]

I live near Sasser, Georgia, USA and I noticed this new looking configuration. There are more or less 200 rail cars setting on the side-track. They have been there for over 2 months, no graffito on any of the cars. There are three cars connected together with only one truck between the 1st and 2nd and 2nd and 3rd. (see pics attached)
Question.... What do they carry?

[AT41B]

1st message only had 1 pic.

[AT41B]

Sorry about that, all 3 pics didn't go.

[Gumboots]

Those are triple articulated well cars, for carrying containers. They work the same way as the H era well cars in my boxcar pack, except that they are triple units instead of doubles. The single trucks are 125 ton rated, because they have to carry the ends of two cars (which is why it says 125 on the side). The ones at the ends of each triple unit are standard 70 ton units (because they only carry the end of one car, which then has a standard connection to the next one).





Would have to check, but at a guess the ones in your photo would be Gunderson Maxi-IV units. Those are more or less what I modelled mine on, but a triple unit is too long to work in RT3 so made them as doubles.

[AT41B]

Thanks Gumboots, I thought they may have been for continuous rail laying.