After eating lunch at the Edgewater Grille to catch Tow 3 coming downstream, I decided to tour Newburgh rather than chase this tow. It was another generic materials tow. I view waiting for yet another materials tow about like I view waiting for yet another commuter train---it is not worth it. But after touring the town, I came back to check the action on the river. Still no upstream activity, but I caught Tow 3 down at the bend.
And when I turned around to look upstream, I noticed that this tow had made it through the locks.
Since I have never seen barges ride that low in the water, I waited to get better pictures. The low riding means a big (12-foot?) draft. They are taking full advantage of the higher river level. It turns out this materials tow was not mundane after all. This is my third writing of the post. I found mistakes in the other two versions. I hope the third time is a charm.
First of all, these barges are designed for denser material than the typical barge that carries coal or grain. Those barges have a superstructure of, judging from the deckhands on the empty barges below, about four feet so that material can easily be loaded significantly above the water line.
The light grey walls set inside the brownish walls are the superstructure that is added to increase the volume of material that the barge can carry. The covers for the middle barge are for a particularly light material because it allows the cargo to be piled even higher.
I have concluded that the inner wall is more than a superstructure. The wall must be a cargo wall that goes all the way to the bottom so that the barge is double hulled and there is air between the inner and outer walls. I need to figure out how to get a picture of an empty barge with the covers open from above instead of from the side to support this conclusion. (Update)
A closer overview confirms that the row next to the towboat has only two barges. So this tow has 11 barges.
Now I can see that about half the height I saw from a distance is the superstructure so these barges are running closer to their water-level design limit than I had imagined. The combination of riding low in the river and the low superstructure is why these are some of the highest piles I have seen piled up on barges.
I've been trying to guess what the cargo types are. The white and grey stuff would not be salt or cement because they would be affected by water and need to be in covered barges. So is it crushed limestone, or gravel, or...? Is gypsum white or grey? My guess is that the brown cargo is sand. I created a list of densities for reference. But I'm going to leave the analysis for another day.