Got schooled by a river in Montana on suction hose placement

I was on a job clearing a channel on the Clark Fork River near Missoula last fall. We were running a 10-inch cutterhead dredge, and I had the suction hose set up like I always do, maybe a 15-degree angle off the bottom. The foreman, this old guy named Carl who's been at it for 40 years, just shook his head and told me to watch. He had me pull it back and drop it almost straight down, just a couple degrees off vertical. The difference was crazy. We went from pulling up mostly sand and small gravel to getting full bites of the bigger cobble that was actually blocking the flow. He said, 'You're not just vacuuming the floor, you're trying to peel the riverbed.' I'd never thought of it like that. It felt counterintuitive, but the production numbers didn't lie. Anyone else have a simple tweak like that that just flipped a switch for you?

2 comments

2 Comments

uma_johnson1d ago

That Clark Fork current will teach you real fast. I had a similar thing happen on a levee repair in Louisiana, where an old hand showed me how a slight change in the swing cable tension kept the bucket from digging in too hard on the turns. It felt wrong until I saw the clean grade.

the_cameron1d ago

Man, that reminds me of a buddy who swore by tilting his concrete saw blade just a hair for a cleaner cut. Looked wrong but worked perfect.