When the alarm bell at the firehouse rings today, several of the newest members of Buffalo’s bravest will grab their turnout gear and jump on a truck — on their way to their first trial by fire.

Fifty-two recruits received their badges Friday evening from Mayor Byron W. Brown and top fire brass, becoming full-fledged firefighters during a commencement ceremony before a standing-room only crowd in Waterfront School.

Many of them will start work today, and others in the days ahead. From their previous station as recruit, they will be thrust into the role of hero, in the eyes of residents, city officials told them.

“After today, our graduates will go to work for the residents and business owners of the City of Buffalo,” Brown said.

Residents “will hope you’ll come and get them out of the worst possible situations,” Fire Commissioner Michael S. Lombardo added.

“People will count on [firefighters] every single day,” said Lombardo, also referring to the families of firefighters as “silent heroes,” anxiously awaiting the return of their loved ones at the end of the day.

This class — the first in seven years for the Fire Department and among the largest ever in the modern era—features many from firefighting families. Two in their ranks— Patrick J. Herbert and Elizabeth J. Lewis— have fathers who lost their lives while in the line of duty.

Herbert is the son of Donald J. Herbert, who suffered a catastrophic brain injury in December 1995, remained in a coma for nearly 10 years before awakening temporarily in April 2005, only to succumb to his injuries the following February.

Lewis is the daughter of William P. “Homer” Lewis, a fire lieutenant who died of kidney cancer in June 2005, two days after his 53rd birthday.

Nearly a dozen other recruits also were honored at the ceremony for their military service.

The recruits underwent a rigorous 11 weeks of training that included instruction on firefighting, technical rescue, emergency medical service and hazardous materials, according to James C. LaMacchia, the chief of fire training.

“They worked diligently to become proficient in the skills they were asked to learn,” LaMacchia said. “It is now that their hard work and diligence has paid off.”

The addition of the 52 firefighters will help fill more than 70 vacancies in the city’s firefighting corps, Lombardo and Brown said.