Crowley Maritime’s newest Tier IV assist tug, Artemis, is expected to begin serving the Los Angeles and Long Beach seaports later this year. The company announced July 31 that it has entered into its fourth long-term charter with Brusco Tug & Barge regarding the new 77-foot Tier IV ship assist tug. The tug, constructed by Portland-based Diversified Marine, would feature 7,000 horsepower with a bollard pull of 96 tons powered by a pair of Caterpillar Marine 3516 Tier IV-compliant engines that meet EPA air emission standards. “We are proud of our Hercules Class tugs and pleased to continue our partnership…