"抓斗式挖泥船" can be translated into English as "clamshell dredger" or "clamshell bucket dredger".
"Clamshell" refers to the clamshell-shaped bucket used on this type of dredger.
"Dredger" (or "dredge" in some contexts) is the general term for a vessel or machine used for dredging, which is the process of excavating and removing sediment from the bottom of water bodies.
Both terms are commonly used in the maritime and dredging industries to describe this specific type of dredging equipment.