Several year-end retirements in the New Haven Fire Department have raised the department’s vacancy rate to nearly a third of existing positions, worrying union leaders who say the situation has become a safety concern.

Most of the department’s 116 vacancies exist within the department’s Fire Suppression Unit, but a significant number are also managerial positions, with last week’s nine retirements including Capt. William Gambardella and Director of Training Matthew Marcarelli. In response to the high number of unfilled positions, the fire department is planning to start training a class of 45 new firefighters by the end of March.

The Fire Union has voiced skepticism about the plan, saying it does not go far enough to address systemic staffing shortages.

“Those vacancies didn’t occur overnight,” said firefighter union president Lt. Jimmy Kottage, who estimates that the fire department has not had a normal recruitment class in five years. “One year ago, we were down 99. The year before, we were down 80. It’s going to take at least two to three years to get back to where we need to be.”

According to a 2013 report, there were 434 applicants to fire department positions last year, almost double the number of applicants seven years ago. The department narrows down applicants, though, with a physical agility test and a background check by the New Haven police. New firefighters are also put on a probationary period for a year, where they are closely monitored by a commanding officer.

“Just putting in a recruit class doesn’t solve the problem, because even if we put a new class in, they won’t see a firehouse for five months because of training,” Kottage said. “In that time, more people could retire.”

Kottage has called on the police department to expedite background checks and says the city needs to make filling fire department vacancies a priority.

The fire department has a history of disagreements with the city, from a 2009 discrimination suit that went to the Supreme Court to a union fight with Mayor DeStefano’s chief administrative officer over funding for positions. Last October, the firefighters union sued the city for failing to find a permanent fire marshal since July 2011, a move that the suit alleges violates Connecticut law.

Patrick Egan, assistant chief of the fire department, did not respond to multiple requests for comment.

Kottage, who attributed part of the hiring delay to “mistake after mistake” by the city, said he believes Mayor Toni Harp will help the fire department fill positions.

“The process to fill a new class for the fire academy is already well underway,” Harp said in a statement to the News. “Applications are in, tests have been taken, and background checks of candidates, conducted by the New Haven Police Department to save money, are underway.”

Harp said she intends to fill vacancies “as we’re able,” since doing so would save the city money in reduced overtime costs.

Kottage agrees that filling positions would cut long-run costs to taxpayers, estimating that some firefighters are working an average of 70 to 90 hours a week.

The fire department is not the only city department experiencing high vacancies. Around a fifth of officer positions at the New Haven Police Department are unfilled, according to officer David Hartman. Hartman estimates that there are currently 100 open spots.

The New Haven Fire Department has an average response time of 4 minutes, 36 seconds and responded to 18,244 urgent medical issues in 2012.

The New Haven Fire Department was established in 1862.