Authors: LCDR David Kowalczyk, LCDR Anderson Ogg, LCDR Jon Potterton
Title: Operating Further than Anyone Else: Logistical and Engineering Challenges Supporting High Latitude Icebreaking
Abstract:
The US Coast Guard is the only military service in the world that sends diesel-powered heavy icebreakers to Antarctica, and also performs science missions in the Arctic. As of this writing, only one heavy icebreaker is active, the U.S. Coast Guard Cutter (USCGC) POLAR STAR (WAGB 10). POLAR STAR’s sister ship, USCGC POLAR SEA (WAGB 11), has been inactive since 2011. To meet the annual Antarctic obligations, significant planning, financial, technical, and logistical resources are directed to POLAR STAR in the 7-8 month window between deployments. To meet our nation’s annual Arctic obligations, the Coast Guard operates and maintains the medium icebreaker USCGC HEALY (WAGB 20). Both POLAR STAR and HEALY have design features that enable them to operate in extreme environments, while these features drive very different dry docking periodicities. This paper will describe and explain the unique challenges of sustaining high latitude icebreaking, and the design features, maintenance requirements, and other solutions employed to address them. Problem Statement: This paper will describe and explain the unique challenges of sustaining high latitude icebreaking, and the design features, maintenance requirements, and other solutions employed to overcome them. Key Points: • Due to the severe vibrations that the ships experience while breaking ice, almost all of the systems on an icebreaker must be examined closely, and in many cases designed differently from standard ship systems. • Polar class icebreakers are designed with a controllable pitch propeller (CPP) system which drives the expensive requirement for annual drydock maintenance. HEALY has a fixed pitch propeller system and only requires triennial dry dockings. • Both HEALY and Polar class icebreakers have unique dry-docking parameters, such as frame-by-frame loading requirements, which commercial dry docks must be certified to meet. • HEALY and Polar class icebreakers have operated in extremely cold and extremely warm environments. Installed equipment and systems must be designed and robust enough to operate proficiently in both climates. Conclusion: As the Coast Guard embarks on a once-in-a generation Heavy Icebreaker program, sustainment needs must be carefully considered and prioritized. The vessel’s equipment must be robust enough to operate in the extreme environments that are anticipated. The vessel’s dry docking requirements will be driven by design and intentionally balanced against the capabilities of the domestic ship repair industry. Lastly, the selection of propulsion equipment will have a large impact on the dry-docking periodicity, which in turn is a driver of maintenance periodicity and cost considerations of the vessel.