I finally changed my mind about pre-dredging after a job in Mobile

I used to think pre-dredging was just a waste of time and fuel, figured you could just adjust on the fly if things got thick. Then last month we had a contract in Mobile, Alabama, and the sediment was a nightmare mix of clay and old shell fragments. The older operator on site, Mike, showed me a data sheet from the Army Corps that said pre-dredging with a smaller cutterhead can cut total project time by 18 percent. I actually saw it play out when we tried it on a test section and the main cut went way smoother. He also pulled up a sediment analysis from 2019 that showed how clay compacts if you don't break it up first. Now I'm sold on the idea, but I'm wondering if there's a depth where pre-dredging stops being worth it. Anyone have a rule of thumb for when to skip it?

2 comments

2 Comments

hugo_ellis10d ago

Sure thing, just ask me to pre-dredge my brain for a smart thought and you'll be waiting forever.

claire_ramirez2210d ago

Hugo brings the kind of helpful advice you expect from someone whose primary tool is a keyboard. That said, the depth question has been gnawing at me since Mobile. The older operator I was with had a rough cutoff - anything under 25 feet and pre-dredging paid for itself, but once you get past 35 feet the extra time and fuel chasing the small cutterhead down there just isn't worth it. Of course, that's just one guy's rule of thumb from a few decades of digging up the Gulf Coast mud.