Aside from making the usual repairs for wear and tear, the restoration aims to return Old Ironsides to an image of its 1812 self.

The USS Constitution has sailed unassisted by a tug boat only twice since 1881, in 1997 and 2012. This summer it sailed with the help of a tug, but still moved by its own power. Friday was the final unassisted sail until the ship has completed its restoration.

Old Ironsides sailed through Boston Harbor Friday for the last time until 2018, as the 216-year-old warship prepares to undergo a three-year restoration beginning early next year.

“She kind of ballooned away from how she was originally constructed,” said Peter Melkus, spokesman for the Constitution. “So one of our goals is to make her as authentic as possible to what we consider the era of her greatest popularity, the War of 1812.”


Melkus said the iconic ship has undergone many repairs since the late 1920s — about once a decade — but many of those did not follow the ship’s original blueprints. For this set of repairs — during which the ship will have weather-worn areas strengthened and the copper plates of her hull replaced, making her more “seaworthy” — the original blueprints of the Constitution’s sister ship, the USS President, will be referenced for accuracy.

On Friday, the Constitution sailed for Castle Island at 10 a.m. and fired a 21-gun salute. The ship set three topsails on its way back from the island and returned to the pier about 1 p.m.

Setting the topsails takes about 150 to 200 people, Melkus said, but the ship’s crew only consists of about 75 sailors. As a result, about 150 Navy chief petty officer selects were trained over the past week to set the sails as part of USS Constitution US Petty Officer Heritage Week.


Those 150 officers are set to be promoted to chief in September. The selects sleep aboard the ship for the week and undergo historical training. Taking the ship out on Friday was the culmination of their training, Melkus said.

Though Friday was the last time the Constitution will sail until 2018, it will enter the harbor one last time without sails on Oct. 17 to celebrate its 217th birthday, Melkus said, which is on Oct. 21.

The ship is expected to be moved to a dry dock for repairs in early 2015.

Kiera Blessing can be reached at kiera.blessing@globe.com.