Posted on July 29, 2026
Manson Construction delivered its new hopper dredge Frederick Paup into service in January 2026, making it the largest self-propelled trailing suction hopper dredge ever built in the United States.
Shipbuilder Seatrium AmFELS, Brownsville, Texas, completed the vessel and handed it over to Manson Construction Co., Seattle.
The Frederick Paup measures 420 feet long and 81 feet wide and carries a hopper capacity of 15,150 cubic yards.
It represents Manson’s largest single investment since the company’s founding in 1905.
A machine built for the toughest US waterways
The Frederick Paup is the largest-capacity hopper dredge in the United States, with size limited by the dimensions of the harbors and channels in which it must maneuver.
A trailing suction hopper dredge works by dragging metal arms, called dragarms, along the seafloor.
The arms suck up sediment and water through large pumps and deposit the mixture into the vessel’s central hold, called the hopper, while the ship keeps moving.
Discharge is through five pairs of bottom dump doors or by pumpout via a bow coupling.
Propulsion is handled by three azimuthing stern drives and two bow thrusters.
Two hull-mounted 34-inch dredge pumps run two hull-mounted dragarms.
Continuous dredging at this scale means the Frederick Paup can clear a navigation channel far faster than smaller vessels cycling in and out of port to offload material.
Power and propulsion figures
The vessel runs approximately 25,000 hp, powered by three Tier 4 Wabtec 16V250MDC main engines and two 12V250MDC gensets, also from Wabtec.
The engines generate electricity that drives electric motors turning the propellers, giving operators precise control over speed and torque.
Technical systems include those for dynamic positioning, power management and integrated dredging control.
Dynamic positioning uses GPS and thruster feedback to hold the ship on a precise course without a fixed anchor, which is critical when working inside a narrow shipping channel.
The vessel has a draught of 28.5 feet and a gross tonnage of 12,141.
It also meets EPA Tier 4 emissions standards throughout its propulsion and generating plant.
Design choices that set the Frederick Paup apart
Design work was handled by Manson in collaboration with naval architecture firm Hockema Whalen Myers Associates of Seattle.
Manson said the effort ensured that major dredging components, including the davits, trunnion system, weirs, pumps, dual drag arms and thrusters, were optimized for safety and efficiency.
One notable feature is a new sliding trunnion carriage fitted to the dragarms.
The sliding mount lets crews adjust the angle and reach of the dragarms to match channel depth without stopping the pump cycle.
The Frederick Paup’s hopper capacity surpasses its predecessors by volume, the Ellis Island and the Glenn Edwards.
The dredger includes accommodation for up to 31 personnel, and all interior spaces are served by an HVAC system for year-round operations.
Where the vessel is working and why it matters
The Frederick Paup departed Brownsville on January 27, 2026, bound for Mobile, Alabama, where it began maintenance dredging on US Army Corps of Engineers navigation projects.
The work keeps access open for deep-draft vessels entering the port.
The Frederick Paup will also be used for beach nourishment and coastal restoration, pumping dredged sand onto eroding shorelines to protect communities during storm seasons.
The US Army Corps of Engineers has set goals for increased beneficial reuse of dredged material, and the new dredger’s capacity supports that mission.
As a Jones Act vessel, it must be US-built and US-flagged, a legal requirement that applies to all dredges working American harbors.
Projects like this reflect broader trends in American heavy equipment logistics, similar to when a dragline moved across Texas in 27 loads to reach a new mine site.
Timeline delays and what comes next
Ordered in 2020, the Frederick Paup was originally scheduled for delivery in 2023 but faced significant construction delays.
The three-year slip is a familiar story in US commercial shipbuilding, where labor shortages and supply chain disruptions hit several large vessel programs in the early 2020s.
The delivery also marks Seatrium’s last from the Brownsville shipyard, which was sold to Karpowership, Istanbul, in September 2025.
That sale means future large dredge construction will need a different American yard, a capacity question the industry has not yet fully answered.
The US Army Corps of Engineers is also building a new medium-class hopper dredge, the Donnelly, at Eastern Shipbuilding Group in Panama City, Florida, with delivery expected in late 2027 to replace the 57-year-old McFarland.
According to Dredging Today, the Frederick Paup was formally christened on the banks of the Mississippi River in New Orleans on March 21, 2026.
The vessel also adds to a pattern of record equipment deployments, comparable to how Big Carl lifted reactor rings into place at Britain’s Hinkley Point C nuclear plant.
For now, the Frederick Paup is the most capable dredging machine flying an American flag, and the channels it keeps open carry billions of dollars in cargo every year.
