If you mean Rail Box Corporation, the answer is here:
http://en.wikipedia.org/wiki/Railbox
I see a lot of these that are still in use on the Union Pacific Sunset Route through Arizona.
Cacole:
Yes, I mean Rail Box box car. I just move to Austin, TX and I saw a few of them passing thru the city. The last time I saw them were in N.J. in the 80's. Thanks for the information. Who's owns the rail line that's passing thru the city? I see allot of boxcar from Mexico?
Since I-10 runs through Austin, the trains you're seeing are probably the same ones that run through southern Arizona parallel to I-10 on the Sunset Route - Union Pacific. I see a lot of rolling stock from Mexican railways here, too, because the Union Pacific exchanges traffic with them at the Nogales, Mexico/Arizona border crossing point.