In my recollection, there were actually a few good dragline operating videos on youtube (years ago).

I also think most of the modern dragline operations are moving gravel or sand in a water environment. A free-swinging bucket just cannot generate any significant break-out force except for a straight drag - which I believe would be the least efficient way to break out a scoop of clay.

I think the advantage of DaveS's machine would still be to muck out ponds. How far can you reach out horizontally with your bucket? Compare that to the massive HP and cost of a long-reach excavator that could reach the equivalent distance.

My dragline ponds are in the shape of a U. The two sides of the "U" are significantly higher than the dam (the bottom of the "U"). I assume the operator constructed the dam first at "design" height and then built the sides by dragging perpendicular to the long-axis of the pond. I guess theoretically my ponds could have been 60' wide and hundreds of feet long based upon that pattern.