Devonshire's accident became an opportunity to modernise

During 1929 gunnery training, a misfire in Devonshire's X turret became catastrophic when opening the breech ignited propellant still inside the barrel. The resulting explosion killed eighteen men and forced the cruiser to return to Britain with the turret and guns badly displaced. Treaty rules explicitly permitted repairs and replacement after accidents, so the Royal Navy could restore the ship without treating the work as forbidden new construction. Devonshire also received a high-angle control system and catapults during the repair, emerging slightly heavier than before. The necessary repair also provided a treaty-compliant chance to modernize the cruiser.