I'm pleasantly surprised you got all the way to the appendix there, Ralph! There were a lot of interesting things that came up as a result of that trestle fill video post. I'd have liked to meet the fellow who authored that article I shared; a very thorough and resourceful man.
My guess is the fellow below in Jerry's photo is making sure those culverts get well bedded in, I've seen some interesting failures when during a period of high flow the water was able to run through the fill outside of the culvert. It gets ugly fast!
Your point about moving the fill hydraulically is also interesting. Somewhere it was mentioned the same method was used in California construction (California Western Railroad?). The gold miners using the big hydraulic guns ("giants") got very good at moving material and with those skills available the two industries of mining and railroad construction inevitably crossed over. The same men were often already working with useful equipment mining when the railroads came through. No one looked over their shoulder much and they did a lot of incredible things to solve problems with what they had. The coming of the railroad represented new things to try and new ways to get themselves and their supplies where they couldn't before.
You can try the basic principles with a hose and some dirt or sand. Instead of trying to move the material away as you normally do, try to put it somewhere.
My buddy Jack who shows up in my White Pass and Yukon thread was from Southern Oregon and actually got involved with the last of the big hydraulic mining while we were in college. I got to meet some of the old timers, one of whom was his next door neighbor Guy Critser (sp?), and we actually found one of the giants he'd left out in the woods decades earlier and forgotten. He and Jack then went back to get it and found it gone. I saw the movie "Paint Your Wagon" shortly thereafter and realized that most people think the characters are caricatures. They aren't. I could tell you many Guy Critser stories from my and Jack's own experience you would think I was making up, and we only knew him when he was an old man.
Like most of the rural Western folks Guy did a lot of things to survive; mining, logging, and working for the Southern Pacific Railroad in the southern Cascades. Jack and I in our younger days roamed all over Southern Oregon (he still is) and there were few places we'd tell him about that he would say he hadn't been, doing something. He had lots of good stories to tell about his life, too, which sent Jack and I on further interesting exploring expeditions into the backwoods. Some of his stories were even true...
Timothy