A rapid intervention unit could replace one fire engine
Ninety-two firefighter posts could be lost in Lancashire under a review of emergency cover in the county.
Lancashire Fire and Rescue Service said the re-organisation would save up to £2.7m with no impact on safety.
The number of fire engines and stations would remain the same, but some crew members could be on duty for 84 hours a week in return for a 35% pay rise.
The Fire Brigades Union (FBU) said aspects of the plan would be like stepping back to Victorian times.
Lancashire Fire and Rescue Service has about 1,100 firefighters, of which about 700 are full-time.
Assistant chief fire officer Peter O'Brien said: "These are significant changes indeed, but essentially they focus on internal arrangements for getting the job done.
"Though the proposals will result in a reduction in firefighter posts, this will be achieved without imposing redundancies," he added.
Steve Harman, from the Fire Brigade Union, says longer working hours are a step back
"There will be no reduction in the number of fire engines in the fleet, no reduction in emergency cover and no closure of fire stations - but we will deliver the same or an improved service at considerably less cost to the taxpayer."
Under the proposals, officers at fire stations which statistically have fewer than average night time incidents would be asked to volunteer for the new optimum crewing system (OCS).
It would mean officers being on duty for 84 hours a week, including 42 night time hours responding from purpose-built accommodation within station grounds.
In reality, crews at these stations would be unlikely to be called out regularly overnight, the fire service said.
The 35% increase in pay for those signing up represents a pay rise of up to £9,000, a spokesman told the BBC.
Steve Harman, county secretary for the FBU, said he "fully supported the intent" behind the proposals.
But he said having crews staying on site for two consecutive days and nights would force families to visit their workplaces to see them.
"Where the children have to be taken to the place of work to visit the parents, it's taking it back to Victorian times," said Mr Harman.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.