USCGC Mobile Bay [WTGB-103]

1979-Present

Icebreaker Tugboat; Paired with barge CGB-12002

Sturgeon Bay, WI

USCGC Mobile Bay, breaking ice on Green Bay, 3/16/2020. Isaac Pennock

Specs

Build Information

Year Built: 1979

Builder: Tacoma Boatbuilding, Tacoma, WA

Hull #–

Registry: US –

IMO # —

Laid Down: 1978

Launch Date: November 11, 1978

Delivered: May 6, 1979

Commissioned: September 2, 1979

PAIRED BARGES:

CGB-12002

Construction

Mobile Bay was the third ship of the Bay Class USCG Icebreaking tugboats. The Bay class vessels were designed to replace the Coast Guard’s aging class of 110′ harbor tugs. The Bay Class tugs feature a strengthened icebreaking hull, and is capable of breaking 20 inches at continuous speed and 6-9 feet while backing and ramming. The Bay Class tugs are also equipped with a unique “bubbler” hull air lubrication system. The bubbler pushes air through ports on the cutters hull, allowing for an upward flow of air and water along the hull, reducing friction and increasing efficiency.

There were 9 Bay Class tugboats constructed for U.S. Coast Guard service, and 6 of them are stationed on the Great Lakes. Those are the Katmai Bay, Bristol Bay, Mobile Bay, Biscayne Bay, Neah Bay, and Morro Bay.

Modifications

Service Life Extension Program, U.S. Coast Guard Shipyard, Baltimore, MD, 2019.

General Stats

Length Overall: 140′

Breadth: 37’06”

Depth: 12′

Vessel Type: Icebreaker Tugboat

Icebreaking Capability: 20” freshwater ice at continuous speed, 6-9′ freshwater ice backing and ramming

Propellers: 1

Rudders: 1

Crew Compliment: 17 [3 Officers / 14 Enlisted]

Engineering Equipment

Original

Engine

Engine Type: Diesel Engines

Engine Manufacturer: Fairbanks Morse, Beloit, WI

Engine Model: 10-38D8-1/8

Number of Engines: 2

Motor

Motor Type: Diesel-Electric

Motor Manufacturer: Westinghouse Electric, Pittsburgh, PA

Rated HP: 2500 BHP

History

Lineage

USCGC Mobile Bay [WTGB-103] – 1979-Present

Owner: United States Coast Guard, Washington D.C.

Operator: United States Coast Guard, 9th District, Cleveland, OH

Flag: United States

Home Port: Sturgeon Bay, WI

Station History

Sturgeon Bay, WI – 1979-Present

Her Story

USCGC Mobile Bay was constructed in 1978 by Tacoma Boatbuilding of Tacoma, WA, as an icebreaking tugboat for the U.S. Coast Guard. She was launched on Veterans Day on November 11, 1978, and delivered to the U.S. Coast Guard on May 6, 1979. USCGC Mobile Bay was commissioned on September 2, 1979, and took up station at Sturgeon Bay, WI.

On May 5, 1992, Mobile Bay was mated with the specially-designed 120′ long Aids-to-Navigation (ATON) tender barge CGB-12002 to allow her to assist with buoy tending duties. She normally sails with the barge from the spring to the fall while detaching for the winter icebreaking season.

In 2019, Mobile Bay went to the U.S. Coast Guard’s shipyard in Baltimore, MD, where she underwent her Service Life Extension Program (SLEP) refit. She returned to the Great Lakes at the end of the year.

USCGC Mobile Bay remains an important asset to the Coast Guard’s Great Lakes icebreaking and buoy tending fleet, and assists in keeping marine traffic moving during the winter months.

Compiled By Brendan Falkowski

Updated on December 17, 2021.