Afterward, "Wallowa" was returned to Foss, which rebuilt and modernized the tug from its main deck up at company headquarters in Tacoma in 1934. The primary component of the rebuild was installation of a state-of-the-art, six cylinder, four-stroke, Washington Iron Works direct-drive diesel engine, which made the tug the most powerful on the West Coast. At re-launch, Foss renamed the tug "Arthur Foss" in honor of the company president and eldest son of company founder Thea Foss. Following successful trials, "Arthur Foss" went into commercial service as the Foss company flagship. However, steering troubles were presumably encountered, for a pneumatic power-steering assist system was installed in 1937. This was likely needed because increased right-hand torque from the propeller due to the more powerful engine made manual steering difficult for a single person.