Choosing heavy coastal guns for Singapore

Would 13.5-inch or 15-inch guns be better for a stored Singapore coastal-defence reserve?

Fifteen-inch guns are preferred, though a mix could work if both calibres had adequate high-explosive ammunition and a realistic defensive role.

Fifteen-inch weapons are preferred to 13.5-inch guns for the hypothetical Singapore reserve. A mixed battery could still work if both calibres had ample high-explosive ammunition. The comparison turns on future usefulness rather than maximum calibre alone: guns, shells, emplacements, and support arrangements must form a workable defensive system. The choice follows the session's recurring test of preserving equipment with a credible employment and support plan.