The Bay-class tugboat is a class of 140feet icebreaking tugboats of the United States Coast Guard, with hull numbers WTGB-101 through to WTGB-109.
They can proceed through fresh water ice up to 20inches thick, and break ice up to 3feet thick, through ramming. They can also ram pressure ridges of up to eight feet in thickness. These vessels are equipped with a system to lubricate their progress through the ice, by bubbling air through the hull.
A SLEP is a major overhaul intended to extend a vessel's service life; it is typically scheduled as the vessel approaches the end of its originally planned service life. The Bay-class tugboat SLEP project includes significant system upgrades and improvements to the propulsion plant; to the heating, ventilation, and air conditioning systems; installation of an engine-room fire-suppression system; boat launching davit replacement; Oily Water Separator replacement; stack exhaust configuration modifications; hull air-ice lubrication system; and crew habitability improvements to meet current standards (including removal of lead paint). When the Coast Guard described the Bay-class tugboat SLEP to the U.S. Congress in 2015, the first SLEP was scheduled to take 12 months; however, the Coast Guard anticipated that after the third SLEP the Coast Guard Yard would have enough familiarity with the process to complete two SLEPs per year, with an anticipated duration of 9 months each. The first of nine cutters (Morro Bay) entered SLEP at the Coast Guard Yard on July 1, 2014.[1] Morro Bay returned to her homeport of Cleveland in September 2015 [2]