The composite tail cone was jettisonable for emergency egress use. Depending on whether the aircraft had rear airstairs or not, you either pulled a plug type hatch or opened the aft bulkhead door and proceeded along a catwalk in the rear compartment. The tailcone could be released from inside or out and a small slide then was used for exit.
Not forgetting the other feature of the Caravelle's tailcone:
I remember watching it being used on many occasions when they flew rugby charters into Edinburgh's 1800m runway.