Before the official Interchange program the Chief described so appropriately ("it sucked"), there was a period of time during which companies were stripped from less busy areas and relocated into high response areas on a regular basis. I would say during the mid 1960s, companies were pulled nightly from Staten Island, for example, and operated in Brooklyn or the Bronx. Lots of complaints from neighbors left without fire protection. Wasteful - a lot of travel time. No one knew the areas they were assigned.
The department formed many double section companies and battalions in the late 1960s to address the increasingly heavy workload.
1970s - FDNY formed a new division, a few new battalions (including the 60th battalion in Bklyn a "floating battalion), a lot of new companies, two temporary firehouses ("Tin House"), adaptive response (reduced 2&1 response afternoons and nite peak hours), tactical control units (engines and trucks), ERS alarm boxes, DRB responses for battalion chiefs, purchased a lot of tower ladders, tried rapid water and other ideas to help the War Years workload. Some worked, some didn't.