President Barack Obama on Saturday intervened in a commuter rail strike in the nation’s sixth-largest metropolitan area, granting Pennsylvania Gov. Tom Corbett’s request to create a presidential emergency board to mediate the contract dispute between the Southeast Pennsylvania Transportation Authority and its engineers and electricians unions.

Obama ordered the establishment of the three-member board effective at 12:01 a.m. today. He called for “a swift and smooth resolution” of the dispute.

Corbett said the president’s action will force workers to return to work and both parties to continue negotiations.

More than 400 workers went on strike at midnight, and no talks were scheduled over the weekend.

Obama is giving the board 30 days to deliver a report recommending how the dispute should be resolved.

“The people of Philadelphia and the surrounding region expect and deserve a safe and efficient rail system to get them to work, medical appointments, school and recreation,” the Republican governor said in a statement. “I call on both parties to work together, find common ground and place the riders at the forefront of mind in their discussions.”

The unions said they would comply with the law, but said the strike is designed to force SEPTA to agree to their demands or accept binding arbitration. Workers are seeking raises of at least 14.5 percent over five years — or about 3 percentage points more than SEPTA has offered.

“Yes, the strike is worth it. It’s our intention to encourage SEPTA to make a reasonable settlement,” Stephen Bruno, vice president of the Brotherhood of Locomotive Engineers and Trainmen, said at an afternoon news conference.

The move shut down 13 train lines that carry commuters from Philadelphia to the suburbs, Philadelphia International Airport and New Jersey. SEPTA said it would take eight to 10 hours to restore service. The agency’s subways, trolleys and buses continue to run.

“My head’s going to hurt by the end of this day,” said volunteer Rusty Schwendeman of the Traveler’s Aid Society, who had helped reroute about two dozen rail travelers Saturday morning at 30th Street Station.

They often involved several connections, longer routes or a significantly higher fare on Amtrak.

Carolyn Tola, of Hamilton Square, N.J., and three friends paid $40 apiece to take Amtrak from central New Jersey to Philadelphia to see the Pennsylvania Ballet instead of $9 on Septa.

“We’re here,” Tola said, noting that the ballet tickets were nonrefundable. “We’re going to relax and enjoy it.”

The strike began after negotiations between the transit agency and two unions failed to reach a new contract deal Friday. The last regional rail strike, in 1983, lasted more than three months.