Tried running the cutterhead at lower RPM to save fuel, almost lost the entire swing

I'm on a job up near the Port of Cleveland, pulling sand and silt out of a turning basin. Fuel costs have been eating me alive so I dropped the cutterhead from 28 RPM down to about 18. Figured I'd still get good production, just slower. First two passes felt fine. Third pass I hit what I thought was a soft spot but the suction started pulsing. Before I could react the whole ladder started vibrating bad. By the time I cut power I had a foot of swing cable slack. That vibration nearly twisted the spud. Took me two hours to get everything stabilized. Lesson learned - that lower RPM changes the cut pattern completely. Has anyone else found a sweet spot for RPM that balances fuel and safety, or am I just running a machine that needs to stay at factory specs?

2 comments

2 Comments

faith_price79d ago

Did you check your swing tension before you started, or did you just rely on how it felt on the last pass? Because I've seen machines where the brake loses hold after a few hours and the whole thing walks off if you aren't paying attention. That pulsing suction is usually a sign the cutter isn't digging evenly anymore, and you might be better off stepping up the RPM just enough to keep the bite consistent.

oscar3908d ago

Yeah I used to just go by feel on the last pass and figured that was good enough. But after reading this I think I was just being lazy with the tension check. I had a machine walk on me once and I blamed it on the ground being wet, but now I'm wondering if the brake just let go like you said. That pulsing suction thing makes a lot more sense too, I always thought it was just a quirk of the machine. I'm gonna start bumping the RPM up a little like you suggested and see if that evens things out.