Loading…
17
A chat with an old timer on the Columbia River changed how I set my ladder.
I was working a gravel job near Portland, and I always set my ladder at a steep angle for more bite. An older operator named Ray saw me and said, 'Son, you're fighting the current, not the bottom.' He showed me how a shallower angle, maybe 20 degrees, lets the flow work with you. We tried it on a test cut and the pump stayed full without bogging down once. Anyone else find a small change like that made a big difference on a sandy bottom?
3 comments
Log in to join the discussion
Log In3 Comments
robert_roberts5mo ago
That shallow angle trick you mentioned about letting material roll in instead of fighting it. Has anyone tried running a slightly longer suction line with that flatter ladder to help the pump breathe even more?
6
laura9927mo ago
We were dredging in a sandy stretch of the Missouri and kept losing suction. My foreman told me to flatten the ladder out until it was almost dragging. I thought we'd plug the pump for sure, but it ran cleaner than ever. That shallow angle just lets the material roll in instead of fighting the sand.
2
elizabeth_bailey267mo ago
Yeah, that shallow angle trick @laura992 mentioned is key for sand. It's all about the entry speed. A steep cut digs in too fast and just packs the sand into a solid wall right at the intake. Letting it roll in slow keeps it fluid. We saw the same thing on a river job last fall, fighting that same dense pack. Floated that ladder nearly flat and the pump just hummed.
4