Breakdowns, delays and cancellations plagued the Steamship Authority fleet over the holiday travel week after two freight boats in a row were taken out of commission.

On the evening of Dec. 23, the freight boat Katama lost steering power in Vineyard Sound, near Nobska Light, on its 5:20 p.m. run to Woods Hole with 78 passengers, seven crew and 29 vehicles aboard.

Guided back by two tugboats, the Katama returned to Vineyard Haven, docking at 8:15 p.m. Woods Hole-bound passengers and vehicles were loaded off the disabled freight boat and onto the Martha’s Vineyard, which got them to Woods Hole around 9:15 p.m. — nearly four hours after their original departure.

The Katama’s 5:30 a.m. trip from Woods Hole the next day was canceled, with the freight boat Gay Head taking over its subsequent sailings. Katama was transferred to the boat line’s maintenance facility in Fairhaven, where it remains.

Also last Tuesday, the SSA canceled two trips by the Martha’s Vineyard after it failed a routine test of its backup generator. After missing its 9:30 a.m. and 10:45 a.m sailings, the vessel returned to service for a delayed noon passage.

Next, it was the freight vessel Gay Head’s turn to go down. On the night of Dec. 28, berthing in Vineyard Haven, the Gay Head’s crew noticed irregularities in the vessel’s throttle controls, according to a statement from boat line general manager Robert Davis provided Monday by the public relations firm Regan Communications of Boston and Cape Cod.

“Upon inspection by maintenance and engineering overnight, the cause was identified as an air pressure leakage at the throttle control,” according to the statement.

With Coast Guard permission, the Gay Head returned to Woods Hole Sunday morning without passengers so that its throttle control could be replaced. The ferry’s first three round trips that day were canceled.

“Efforts were made to contact customers with reservations on the impacted trips and the lift decks on the M/V Island Home were placed into service,” the statement continued.

Following repairs and a sea trial, Gay Head returned to service and departed Vineyard Haven shortly after 12:30 p.m. Sunday, according to the SSA statement.