Man, I had the same reaction when I saw a dredge setup on a job site a few years back. They were pumping sand and water almost a mile and a half through a pipeline across fields and roads, and I couldn't believe it just kept going without clogging. The noise was a low hum you could feel in your chest from way far off, but the neighbors got used to it after a few days. Have you seen the massive impellers they use inside the pump?