hydraulic dredger造句

• It produced ironclad warships and other materials for the Royal Navy to exponential profits during the Napoleonic Wars and completed several large contracts for the East India Company It also built paddle steamers and hydraulic dredgers.
• A hydraulic dredger, unlike the old-fashioned old clamshell machines that were used in traditional dredging work, is essentially a giant box that would be placed at the river's bottom over the contaminated area, with gaskets that then seal that area from the rest of the river.