R. B. Forbes was in service by early January 1846. She was used as a towboat in
Boston Harbor, bringing
clipper ships into the open ocean. In 1847, when
USS Jamestown began her journey to Ireland to provide relief related to the
Great Famine, the organizers of the relief mission watched from aboard
R. B. Forbes. In September 1850, she suffered about $100 () of damage in a fire.
R. B. Forbes also briefly saw service as a
lightship: from April 18 to May 22, 1851, she was stationed at
Minots Ledge while the regularly assigned lightship was en route. She towed the clipper
Great Republic from Boston to
New York City in 1853. Seven years later, the vessel towed the
schooner Spring Hill (later known as
United States) to
Nantasket Roads in preparation for
Isaac Israel Hayes's Arctic expedition. In 1860, the
Wilmington Daily Herald described her as "as sound now as when first built" and compared her favorably to the similar, but wooden, vessel
Enoch Train.
R. B. Forbes was not financially successful, and went through several owners. In 1861, the
Union Navy purchased the ship for use in the
American Civil War, at a cost of $52,500 (). The acquisition began on August 17, but was not formalized until September 20. The vessel was
commissioned in August. After being outfitted in Boston,
R. B. Forbes left on August 25 under the command of
Acting Master William G. Gregory for the
Washington Navy Yard, where she spent most of September. The Navy armed her with two 32-pounder cannons and a
rifled 30-pounder gun. She was manned by a crew of 51.
R. B. Forbes was first assigned to service in the
Chesapeake Bay area, but then was ordered to join the
South Atlantic Blockading Squadron. Having left to join the blockading squadron in late October, she arrived in time to fight in the
Battle of Port Royal on November 7; the battle ended with Union forces capturing
Fort Walker and
Fort Beauregard from the
Confederates. Under the command of
Lieutenant Henry S. Newcomb, the vessel fired 43 artillery rounds at a Confederate
artillery battery on land. Newcomb reported that some of the shells fired had issues with jamming in the cannons' barrels. After remaining in the Port Royal area until December, she was towed to New York by the steamboat
Atlantic, as she had suffered damage to her
port shaft and propeller. After arriving on December 20, she was decommissioned for repairs. After being recommissioned on February 8, 1862,
R. B. Forbes was ordered to journey to join the
Mortar Flotilla, a collection of ships armed with
mortars designed to bombard fortifications into submission, near
New Orleans, Louisiana. During the way, she was caught in a storm on February 25, off of
Nags Head, North Carolina, and driven onto the
Currituck Banks. Her propellers were broken during the wreck, and as it was deemed impossible to get her dislodged, she was burned to prevent capture. The ship's crew and salvageable equipment were taken off by . ==See also==