VESSEL REVIEW | Cowlitz – Compact tender to support river and port channel dredging in Oregon

The Port of Portland in Oregon recently placed a new workboat into service.

Cowlitz was designed by naval architecture firm Glosten and built by Nichols Brothers Boat Builders of Freeland, Washington. She will primarily serve as a tug for towing and pushing pipeline strings and barges as well as a tender that will support dredging activities at the Port of Portland and in the navigation channels of the nearby Columbia and Willamette Rivers.

The Columbia River system in particular experiences frequent deposition of sediments, resulting in lower water levels that could affect navigation through tits he channels. With dredgers and dredge tenders readily available, the removal of sediment can be carried out more efficiently, minimising the impact on deeper-draught vessels.

Electrically driven deck machinery for more precise control

The new dredge tender is named after the Cowlitz River in Washington State. She will replace W.L. Williams, the port’s current workboat that had been used to support inland waterway dredging operations in the same area.

Cowlitz is a 69-foot (21-metre), 190GT twin screw workboat with a double-chined hull, a pram bow, and push knees, as well as a full suite of electric deck winches from Markey to provide the crew with full operational functionality. Electrically driven deck equipment ensures more precise control compared to conventional machinery, which will in turn facilitate more accurate positioning when operating amid currents.

The workboat was designed to meet US Coast Guard Subchapter M requirements. Glosten subsidiary Noise Control Engineering performed habitability noise predictions to enhance crew comfort and meet the port safety department’s noise requirements.

The tender utilises a standard pusher tug design with a noticeably elevated wheelhouse. This arrangement provides the bridge crew with improved forward visibility from the helm station, allowing the tender to safely push stationary vessels such as barges and the Port of Portland's own cutter suction dredger Oregon.

Configured for lower-emission operations

Power for the workboat is provided by two Caterpillar C18 US EPA Tier III engines. These drive propellers to enable her to position the dredger Oregon as well as support equipment where needed. These also provide the manoeuvrability necessary for navigating in busy port and channel waters.

According to the Port of Portland, the engines can generate up to 70 per cent fewer emissions compared to those on the earlier W.L. Williams.

Cowlitz was launched in October 2025 and was handed over to the Port of Portland in December, placing her in service just before the start of the 2026 Columbia River dredging season.