Update: A guy on a barge in Mobile Bay said he runs his cutter head slower in heavy clay

I was grabbing coffee near the docks last week and overheard a crew chief talking about their suction dredge. He said they cut their head speed from the usual 12 rpm down to about 8 when they hit a thick clay layer. He claimed it stopped the pump from bogging down and saved them a ton of time on a clogged screen. I tried it yesterday on a muck job near the river bend and it actually worked way better than just ramming through. The spoil was way more consistent and we didn't have to stop once to clear the ladder. Has anyone else tried tweaking the cutter speed like that for different bottom types?

3 comments

3 Comments

lily3943mo agoTop Commenter

That's interesting, but honestly we've had the opposite experience on my crew. Running slower in our stiff clay just lets it pack and glaze the cutter head, then we're stuck doing a full stop to chip it out. We keep the rpm up and use more water at the jets to break it up before it hits the basket.

mila_craig43mo ago

Maybe it depends on your pump size, because a bigger unit can handle that slower feed.

jade88527d ago

Hold up, @mila_craig4 said what now? Ngl, that thought literally makes my skin crawl a little because we tried bigger pumps on a job with heavy sand once and it just made the mess worse, not better. The slower feed let all that grit settle right onto the cutterhead and it locked up the whole rig before we even got halfway down the trench. I'd rather pull the pump halfway through a pour than stand there chipping out crusted clay for an hour, that's nightmare fuel.