The District’s fire chief is to announce Tuesday that he wants to put more ambulances on the streets during peak times, starting roughly with the morning rush hour, and curtail service during slower overnight periods.

A department spokesman said that the city’s fleet of 14 paramedic units, which have the most advanced lifesaving equipment and best-trained personnel, would be pulled from service from about 1 to 7 a.m. under a proposal that would require D.C. Council approval.

That change would allow the department to put more paramedic units on the street when fire and rescue officials say they’re needed most — from early morning to about midday, they said.

“We’re going to ramp up those busy times,” said Lon Walls, the communications director of the D.C. Fire and Emergency Medical Services Department

Fire Chief Kenneth B. Ellerbe said the planned changes are based on “over a year’s worth of data that we have gathered.”

Ellerbe said that the overnight shift includes 42 paramedics staffing 14 advanced life support vehicles. Unlike those who staff basic life support ambulances, paramedics can administer drugs, insert tracheostomy tubes and perform other more advanced tasks.

The chief said that under the new plan, the hours of 1 to 7 a.m. would be staffed by 21 paramedics who travel on fire engines or trucks — which typically respond to medical emergencies anyway — and seven supervisors who are trained as paramedics.

In addition, Ellerbe said there would be 21 to 25 basic life support ambulances available.

Officials said that the current system, in which paramedics do two evenly staffed 12-hour shifts a day, does not work because the most serious calls come between the hours of 7 a.m. and noon. Instead, they said, there would be multiple 12-hour shifts that overlap during busy hours under the new system.

D.C. firefighters and medics respond to about 160,000 calls a year. Eighty-five percent of those calls are related to medical issues.

Union officials for the city’s emergency workers did not immediately return calls Monday.