The WOTAN Retrofit: From Gulf Operations to Alaskan Ambitions
- J.Anthony Tedpahogo
- 6 days ago
- 4 min read
After more than 25 years supporting Manson’s Gulf & East Coast operations, the derrick barge (“DB”) WOTAN has returned to the West Coast for the first time since 1998. The vessel is undergoing a significant retrofit for use on the upcoming Port of Alaska Modernization Program (“PAMP”) Construction Services Terminal 1 (“T1”) Replacement project, serving the Municipality of Anchorage ("MOA").
As the second-largest-capacity derrick barge in Manson’s fleet, the WOTAN’s reintroduction to the West Coast marks a strategic shift toward expanding project opportunities for Manson, according to Gulf and East Coast Equipment Manager Mike Coakley. Her primary focus will now be to drive heavy large-diameter piling, so significant enhancements are necessary to allow that to happen.
Seeking a vessel tailored to the demands of the five-year T1 Replacement project and future endeavors, Manson selected the WOTAN because of its optimal size, lifting capacity, and current ABS classification for marine and offshore sectors. The retrofit features significant modifications to the crane boom, the construction of a new crane housing, installation of two Tier 3 main generators, addition of three new winch drums, and upgrades throughout the vessel.
To execute the retrofit, team members from Manson’s Equipment Department in Seattle, WA and Houma, LA collaborated, dividing the project into two phases: Phase 1 in Manson’s Houma marine yard, and Phase 2 in Manson’s Seattle marine yard.
Kicking Things Off in Houma
Following routine dry dock maintenance at a Louisiana shipyard, the WOTAN was moored in the Houma yard, where crews prepared for an overhaul of the 300-ft-long, 500-ton-lift-capacity barge.
Under Mike’s leadership, the Louisiana WOTAN project team—consisting of Manson equipment designers, welders, Z-Drive technicians, and port engineers—spent two months coordinating detailed plans to ensure seamless execution. Their efforts were supported by Vice President of Equipment Brad Martin and Equipment Engineering Manager Nick Maddox in Seattle.
“The team would meet frequently to discuss weekly goals and ensure everyone was aligned on tasks,” says Welder and Fitter Foreman Jimmy Marcel. “Brad and Nick made the process smooth and provided support whenever needed.”
In May, work commenced on the crane housing machinery. Utilizing the DB HAAKON and the Houma yard crane, the team removed all exterior walls and panels to expose the WOTAN’s old winch drums.
With the old structure cleared, crews removed a CAT 3508 900-kW generator and a CAT D398 800-kW generator, which will be replaced in Seattle with two new CAT C18 510-kW generators. This upgrade will boost power more efficiently and significantly compared to the previous configuration with the ability to parallel (connect) the new generators.
Simultaneously, additional crews installed new winch components, including a double-drum HBL 350 unit to support two each 2-inch auxiliary lines and a Clyde Frame 16 Main Fall winch with 1.5-inch wire. A newly fabricated 20-ft boom insert extension section, complete with an accessible walkway for crew to safely transit the boom, was fabricated and shipped from structural steel fabricator Oil States in Houma. Using the HAAKON, crews removed the 200-ft old boom tip and replaced it with the newly configured tip, extending the main fall (primary cable) to 220 ft from the WOTAN’s heel pin. This enhancement increases the capacity and speed of the WOTAN for piledriving operations.
With the generator and winch components replaced, crews assembled newly fabricated panels to construct a larger crane house—expanded by 4 ft in height and 10 ft in width—to provide more room for larger hoist and electrical components.
“The panels were designed by the Equipment Department and fabricated locally at Main Iron Works in Houma,” Mike says. “Having the fabricator nearby made it easy to quickly deliver the panels to the yard.”
After three months of meticulous execution of Phase 1, the WOTAN crew set sail for the Panama Canal in September on a planned month-long journey.
“Much of the work completed in Houma was in preparation for the remaining tasks in Seattle,” says Houma Port Engineer Jay Price. “The crew worked under tight deadlines to ensure the first half of the retrofit was ready for the West Coast team.”
Work in Seattle
The WOTAN arrived in Seattle as scheduled, where crews were ready to tackle the next five months of work.
Guided by Seattle Equipment Managers Ken Feldhacker and Daric Latham, yard personnel—including port engineers, mechanics, electricians, and welders—embarked on Phase 2. This phase encompasses rearranging the crane tub and stern house to create accommodations for crew and staff, installing the new generators, upgrading LED lighting on the boom and throughout the vessel, installing winch motors and variable frequency drives, re-working controls, hanging tire fenders, and providing hoist power to the spuds, as well as a fresh coat of red and white paint.
With the retrofit on track for completion by March 2026, the WOTAN will be ready to take on transformative projects such as the T1 Replacement in Alaska.
“The market is ever-changing, and the WOTAN’s capabilities give us a competitive edge,” Mike says. “This retrofit and relocation open up new opportunities for us to secure more projects.”
