gun, she had a prototype aircraft catapult, enabling her to carry six Fairey IIID floatplanes on active service. Her revised gun armament thus consisted of six rather than seven 7.5-inch guns (a single 'A' gun forward, two on the wing mountings, and 'X', 'Y' and 'Z' aft - though only the 'X' and 'Y' mountings were actually additions to her armament, the rest having been carried by her as a carrier), and a revised anti-aircraft configuration of three 4-inch guns like Frobisher and Effingham. In 1925, it was suggested that Frobisher and Effingham could be rearmed to carry six guns in the same modern twin-turrets used on the new County-class cruisers then building, giving ships of comparable firepower for a fraction of the cost, and a similar reconstruction of the partially coal-fired Hawkins could also be used to upgrade her boilers (Vindictive was excluded as her aircraft catapult was considered a valuable asset); but the proposal was rejected - the existing turret design produced for the new cruisers could not be used in the aft position on the older ships, their protection against long-range gunfire was weak, there were concerns with staying within the 10,000-ton weight limit, and the Admiralty reported that it would be difficult and costly to find substitutes to take over their duties while they were being rebuilt. Instead, Hawkins underwent a more limited refit in 1929, in which her coal-fired boilers were simply removed and her remaining eight boilers were uprated to , though this would have had the effect of reducing her top speed. She also had her anomalous secondary armament of four 12-pounder guns replaced by an equal number of the same Mark V guns used by her sisters. In 1930, another modernisation plan was proposed, which would re-arm the class with eight guns in twin turrets, similar to the new Leander-class light cruiser. This would have been easier to achieve than the earlier proposal for twin 8-inch turrets, but again, nothing was done. The British government was placing a strong emphasis on establishing agreed limits on heavy cruiser numbers in the word's major navies, and an offer to remove the Hawkins class from service was instrumental in obtaining the London Naval Treaty, which implicitly accepted that they would all be removed from service by 1936. Simply converting them into modern light cruisers would hardly have honoured the spirit of the agreement. The Hawkins