Railroad ties

When riding my bicycle this afternoon I saw a pile of railroad ties near the road.  They were sprayed with the word "free".   Unlike the chair I recently got, I couldn't haul these ties on my bicycle.  When I got home I drove my pickup and picked them up.   The ties were ok but nothing I would pay for.  They were old and the bottom parts that had been laying on the ground are starting to decay.  I can use them as fence posts.  But way out in a pasture where looks don't matter.  And a few of them have "free" spray painted on them in orange paint.

I don't know what the previous owner used them for, but all the ties had these very long nail screws in them at each end of the ties.  Maybe to hold them in place in the ground?   It was an effort to remove the nails.