ROCKLAND (AP) – Officials are trying to silence passenger train whistles that disturb the slumber of residents at three closely connected crossings in the city’s South End.

The problem came to the fore Saturday when a special Maine Eastern Railroad train arriving for the North Atlantic Blues Festival sounded its whistle as it passed through the crossings at 4:30 a.m.

While city officials have praised the return of passenger train service to Rockland Station three years ago, Mayor Brian Harden said the whistle-blowing at crossings was intolerable.

“As much as I love the return of the train to Rockland, whistling at that hour is unacceptable and disruptive at a time when most residents are sleeping,” Harden wrote in an e-mail to city councilors.

Maine Eastern’s general manager, Jon Shute, said the whistle-blowing was required under Federal Railroad Administration rules.

But under an agreement reached Monday by city, state and railroad officials, there will be no whistle-blowing at the crossings before 9 a.m. or later than 8 p.m., according to Nate Moulton, manager of rail for the state Department of Transportation.

When the whistle is silenced, Maine Eastern will place a qualified “flagger” on the ground at each crossing. Federal regulations permit the use of a flagger instead of a whistle if the train is traveling at a maximum of 15 mph.

Meanwhile, the city is working on filing a federal application to establish “quiet zones,” Moulton said, but it could take months before it might be approved. Five other South End crossings are exempt from whistle-blowing under a state-approved ban.

Moulton said Rockland will probably qualify for quiet zones with gates and lights only. But if the FRA requires additional protections for a particular crossing, such as traffic islands, four-way gates or creating a one-way street, the city is responsible for the costs, he said.

Freight trains that run along the Atlantic branch to Dragon Products waterfront terminal don’t pass through the branch crossings that require whistle-blowing.