Editing Lexington-class aircraft carrier (section)

==Development==
[[File:Lexington battlecruiser conversion models.jpg|thumb|left|Rear Admiral David W. Taylor (left), Chief of the Bureau of Construction and Repair, and Rear Admiral John K. Robison (right), Chief of the Bureau of Engineering, hold a model of the battlecruiser above a model of the proposed conversion to an aircraft carrier at the Navy Department on 8 March 1922.|alt=Two men in naval officer uniforms hold the ends of a two-meter model of a battlecruiser above a similarly sized model of a conversion to an aircraft carrier. Four men, mostly in civilian clothes, stand behind the models. The battlecruiser model has two large funnels and eight guns, and the conversion has a huge funnel and a long flight deck.]]

The ''Lexington''-class ships were [[Lexington-class battlecruiser|originally designed]] to be battlecruisers, with heavy guns, high speed, and moderate armor protection. The Navy laid down six ships of the class in 1919–20. When the battlecruisers were cancelled under the Washington Naval Treaty of 1922, two of the unfinished ships were designated for completion as carriers. ''Lexington'' and ''Saratoga'' were selected since they were the most advanced of the six ships in construction.<ref>Stern, pp. 27–30</ref>

Conversion became a series of compromises and mixed blessings which would not have arisen had they been "specifically designed carriers" from the outset. On the plus side, the ships would have better anti-torpedo protection, larger magazines for aircraft bombs and, with the aft [[Elevator#Aircraft elevators|elevator]] {{convert|28|ft|m|adj=off}} higher than otherwise, more room for aircraft landings. On the minus side, a converted battlecruiser would be {{convert|0.5|kn|lk=in}} slower than a specifically designed carrier, have 16 percent less hangar space, less emergency fuel and, with "narrower lines" aft, not as wide a runway for which to aim. Costs were similar. A brand-new aircraft carrier was estimated at $27.1 million. Conversion of a ''Lexington'' class was $22.4 million, not counting the $6.7 million already sunk into them. Added together, the figure rose to $28.1 million.<ref name=Friedman43>Friedman, p. 43</ref><ref group=N>Both of these figures (the $6.7 and $22.4) are estimates for one of the lesser-advanced ships like ''Ranger''. The former cost would be higher and the second lower for one of the more-advanced ships.</ref>

The bottom line, with the signing of the treaty, was that any [[capital ships]] under construction by the five signatories (the United States, Great Britain, France, Italy and Japan) had to be canceled and scrapped. For battlecruisers, this encompassed the United States{{'}} ''Lexington'' class, Japan's {{sclass|Amagi|battlecruiser|4}}, and Great Britain's [[G3 battlecruiser]]s.<ref>See: [[s:Washington Naval Treaty, 1922#SECTION II REPLACEMENT AND SCRAPPING OF CAPITAL SHIPS|Washington Naval Treaty, Chapter II, Part III, Section II]]</ref> For the U.S. Navy, the choice seemed clear. If it scrapped all six ''Lexington''s in accordance with the treaty, it would throw away $13.4 million that could otherwise go toward aircraft carriers. The Navy opted for the latter course.<ref name=Friedman43/><ref name="Doooomed">{{cite DANFS |title=United States |url= http://hazegray.org/danfs/cruisers/cc6.htm |access-date=5 December 2008 |short=yes}}</ref>

The next challenge the Navy's [[Bureau of Construction and Repair]] faced was the tonnage cap set by the treaty. Carriers were to be no more than 27,000 tons. An exception, spearheaded by [[Assistant Secretary of the Navy]] [[Theodore Roosevelt Jr.]] and added to the treaty, allowed capital ships under conversion to go up to 33,000 tons, an increase of 6000 tons.<ref name=Friedman43/><ref>See: [[s:Washington Naval Treaty, 1922#Article IX|Washington Naval Treaty, Chapter I, Article IX]]</ref> This would almost not be enough for a conversion without removing half the power plant, something the Navy General Board did not consider an option. Creative interpreting of a clause in the treaty allowed a potential way out of this situation.<ref name=Friedman43/> The clause (Chapter II, Part III, Section I, (d)) read:

{{Blockquote|No retained capital ships or aircraft carriers shall be reconstructed except for the purpose of providing means of defense against air and submarine attack, and subject to the following rules: The Contracting Powers may, for that purpose, equip existing tonnage with bulge or blister or anti-air attack deck protection, providing the increase of displacement thus effected does not exceed 3,000 tons (3,048 metric tons) displacement for each ship.<ref>See: [[s:Washington Naval Treaty, 1922#SECTION I.-RULES FOR REPLACEMENT|Chapter II, Part III, Section I, (d)]]</ref>}}

Without this clause, conversion might not have been feasible. Estimates made in 1928 for the two ships put ''Lexington'' at an actual tonnage of 35,689 tons and ''Saratoga'' at 35,544. On official lists, the number given was 33,000 tons, with the footnote, "[this number] does not include weight allowance under Ch. 2, pt. 3, Sec. 1, art. (d) of Washington Treaty for providing means against air and submarine attack". This tonnage was used by these ships for their entire careers.<ref name=Friedman43/>