I think they may have covered the ties with gravel or rock. I know they ran a skid steer all over it they actually used that to carry and drop the ties.
Never felt comfortable stopping and asking questions and more so now cuz then He'll know I'm nosey but wouldn't you take a second look?
Ah hah! I think I've got it: LD didn't say if the railroad ties were vertical or horizontal. My guess is these are redneck Caissons. Depending on the color of the barn of course. If they look this good 40 years under a train track, they'll be in place long after your neighbor has departed.
I did a project down at Barbours Cut where we did concrete encased rail on wood ties. The wood ties were completely encased in concrete.
If the barn builder was trying to save a buck, the savings in displaced concrete doesn't equal the cost of buying, transporting and handling the used ties.