n
11

My foreman in Galveston insisted on running the cutter head at 12 RPM for silt, I thought he was nuts

I was on a channel maintenance job and wanted to crank it up to 18 to move more material. He said at that speed we'd just make a cloud and lose suction. Ran it his way for a shift and we cleared 30% more yardage without clogging the pump once. Anyone have a good RPM chart for different bottom types they'd share?
3 comments

Log in to join the discussion

Log In
3 Comments
graym49
graym4924d ago
harper_wright mentioned clay with a 6-inch pump, but for clay you actually want to run the cutter head slower, not faster than silt. Clay is sticky and heavy, so if you spin too fast it just balls up and clogs everything. I ran a 10-inch pump on a clay job in the Mississippi and we had to keep it at like 8-10 RPM max or we'd lose prime every 15 minutes. Silt is way more forgiving since it breaks up easier, so you can push it a little more. david739 is right about keeping phone notes though, I do the same thing for each job now.
9
david739
david7391mo ago
Man, your foreman was spot on. I learned that the hard way on a sand bar job. Pushed my cutter to 20 RPM thinking faster is better, and we just churned up a huge mess that killed our pump efficiency all afternoon. Slowed it down to match the material and it was like night and day. I don't have a chart, but I keep notes on my phone now for sand, silt, and clay. What pump setup were you running with that?
4
harper_wright
Yeah, I had to learn that lesson with a 6-inch pump on clay.
2