Code-named ORCA, the program was kept secret until just before the election in order to prevent hacking of the system. It was then trumpeted by Romney’s aides as an unrivaled high-tech means of communicating with more than 30,000 field workers who were stationed at polling places on Election Day. Those volunteers were supposed to track who voted and to alert Boston headquarters if turnout was lower than expected at key precincts.

But at Boston’s TD Garden, where 800 Romney workers were staffing phones and computers in coordination with the field workers to oversee the turnout, the surge in traffic was so great that the system didn’t work for 90 minutes, causing panic as staffers frantically tried to restore service. Some campaign workers also reported that they had incorrect PINS and had not been informed that they needed certification to work at polling places.

“The Garden definitely kind of buckled under the strain,” Zac Moffatt, the campaign’s digital director, confirmed in an interview. “The system wasn’t ready for the amount of information incoming.”

Despite the problems, ­Moffatt said, the campaign had reports by the end of the day from 91 percent of counties, with information about 14 million voters, and he discounted speculation from frustrated campaign volunteers who worried the problems might have cost Romney the election.

“I definitely understand the frustration of people,” he said, while adding that the problems were not “election determinative.”

Romney himself trumpeted the program shortly before Election Day in a video message to volunteers. Titled, “Thank you for your help with Project ORCA,” the video showed ­Romney saying he was “encouraged to hear how well it is coming along. As part of this task force, you’ll be the key link in providing critical, real-time ­information to me and to the staff so that we can ensure that every last supporter makes it to the polls. With state-of-the-art technology, and an extremely dedicated group of volunteers, our campaign will have an unprecedented advantage on Election Day.”

But the technology did not live up to Romney’s billing, at least during the crash. The campaign did not respond to a question about whether a particular contractor was primarily responsible for the program but said it was overseen by staff.

While campaign workers in Boston struggled on their end to get the system back online, volunteers across the country reported a variety of problems, some of them unrelated to the issues at the Garden.

John Ekdahl Jr., a 34-year-old Romney campaign worker and Web developer from Jacksonville, Fla., said in a telephone interview Friday that he was sent a 60-page document by the campaign Monday that included instructions on how to use the program and a list of voters at his polling place. That sent him on a frantic run to find a store to print out the documentation. Still, as a web developer, he felt comfortable with the ORCA program, which is actually a webpage and not a typical smartphone app.

Ekdahl’s instructions were to go to his polling place with the list of voters, use the secure campaign web page, and push a virtual “slider” on his phone to alert Boston that an individual had voted. In theory, this was a 21st century equivalent of the traditional “strike list,” in which campaign workers check off names of voters on reams of paper so that headquarters can know who cast ballots. The idea was to make everything happen instantaneously, with the names sent via the ORCA application to headquarters, where workers would try to track down likely supporters who had not turned out.

But when Edkahl went to his polling place with the document and his smartphone, he was told that he needed a certificate to allow him to work there. Checking his document, he found that he was not told about the certification. He spent several hours trying to tell the campaign about the problem but got nowhere. He gave up at 2 p.m., depriving the campaign of data at his station. He said he heard from a number of other volunteers across the country who had the same problem.