Back in the early fifties, the federal govt., due to the cold war, bought and loaned CD pumpers to many cities. New York was one of the cities. These pumpers were given a life span of a number of years. They were not to be used by the city except for major disasters. In the late sixties and early seventies, the fire department fleet was in a shambles. At this time these pumpers became a major source in the spare pool. As I remember these rigs were fast and loud.
An example of how bad the fleet was that one night Ladder 54 was sent a spare which was the tiller that was assigned to proby school. When the radio shops were notified that the spare needed a radio, they informed the Captain that it was a condemned rig and should not have left the "Rock."
In 1974 I went to Engine 75 and the situation was not much better with the spare fleet. I remember once doing at least 8-10 changes in a month's time. One of these was done in the midddle of the afternoon on Fordam Rd and Kingsbridge, a major intersection in the Bronx.