Why the Royal Navy's change from hammocks was not a clean break

What was the last Royal Navy ship class built with hammocks as the primary sleeping accommodation?

The transition centers on the 1949 Daring class, but it was gradual: later ships and patrol craft could retain hammocks, and sailors sometimes chose them even when bunks were available.

The 1949 Daring-class destroyers were the first Royal Navy class designed without hammocks as the primary sleeping arrangement, although even they retained some provision for them. Accommodation changed unevenly by ship, rank, and available space, and some sailors preferred the familiar hammock even when assigned a bunk. The example of a senior chief stringing a hammock beside his bed shows why official design milestones and actual shipboard practice can diverge.