Why some Tribal-class gun fits differed

What gun differences existed among Tribal-class destroyers?

The main wartime change replaced the after 4.7-inch mounting with a twin four-inch high-angle mounting because the original main battery could not elevate far enough for air defence.

Most Tribals retained their 4.7-inch main battery, but wartime air-defence pressure changed the after position on some ships. The X mounting was replaced by a twin four-inch installation because the 4.7-inch guns could not reach a sufficient elevation. Some members of the broader Tribal group began with all four-inch armament. The variation was a response to anti-aircraft requirements rather than a simple national styling difference.