The Yorktown Class has long been saddled with an original sin...well not really a sin, but a mistake, that has plagued these ships since the late 1930's. The old actual OA length bugaboo. Was it 809 feet 9 inches or was it 824 feet 9 inches? It was actually the latter, 824 feet 9 inches OVERALL, AS BUILT, for all three. I will lay this goof to rest decisively, for all time, right now.
Okay, where did the goof begin? DANFS seems to be the main culprit for this dis-information, followed by many authors quoting the erroneous figures, followed by notable web sites, like CV-6.org, all repeating the basic error. Some sites do get it right. The Floating Drydock's Hornet Battle Damage book gets it right, as do their plans, Webb Warship's plans, The Maryland Silver Co. massive plans and blueprint books get it right, and guess what, the original USN builders plans, you guessed it, got it right!! Imagine that, builders plans that have the real length figures, right on them. Who'da thunk it.
Here is how I think this dirty yellow snowball got started downhill. DANFS puts supposedly "as-completed" figures in its listings. Unfortunately, in the case of all three Yorktowns, they put "as originally designed" not "as completed" figures in the listings. It all has to do with that rear flight deck overhang, which extends past the fantail on the hull by fifteen feet to the edge of the ramp. That overhang was not a part of the original contract design laid out in 1934. It was a later amendment, made during early construction stages.
The aviation community lobbied for the flight decks to be extended to overhang the forpeak and the fantail. BuShips said no on the bow, fearing flight deck damage in heavy seas. (Hornet's namesake CV-12 and Bennington, CV-20 would later prove the wisdom of that position). Fear of damage in shipping water over the bow seems also to have driven the bevelled corner shape of CV-5 and CV-6 flight decks. The earliest design drawings had squared flight deck ends, but well short of the hull dimensions. Based on experience with CV5 & 6 in service, BuShips gave in a little when CV-8 was building, and allowed the forward edge to be widened and squared off, as the aviation community felt the narrowing at the bow in CV5 & 6 increased the pucker factor when a pilot might drift off centerline on takeoff. Also, as all three had H-2 cats, this allowed a for planes with a much wider landing gear track to use cat launches on Hornet, where wide track gear planes might have their outboard main wheel run off the deck edge before clearing the cat track. This wider front ramp might also explain why she was the natural selction to launch Doolittle's B-25's, aside from availability. Ever look at the main gear white deck stripe on the Tokyo raid launch photos? That line would be right on the edge of the deck before the ramp was reached had CV-5 or 6 been used. The forepeak on all three ships extends 8 feet, 9 inches beyond the edge of the forward flight deck ramp. (Keep that figure in your head, 8'9").
CV5/6 bow plan:
And CV-8 bow plan:
BuShips DID however, concede to the extended deck overhang at the stern. CV-5 and CV-6 were both completed with this full overhang in place, as any look at their fitting out photos and shakedown photos reveal. CV-8 had the overhang from the instant it was decided she would be a repeat Yorktown, and not modified in any radical way. Norman Fridman's chapter on the Yorktown class, in his US Aircraft Carriers, An Illustrated Design History, describes the early CV-8 proposals in detail. Friedman also makes mention of the arguments for the overhangs, and how BuShips reserved judgement on the stern overhang in 1934, but he never closes the open question, namely, that the overhang was in fact, eventually included by 1937, and the ships accordingly completed that way.
Here is the original approved design in March 1934. Note the five inch gun on the fantail. Lots of Ranger CV-4 influence here:
The bow also had a five inch originally planed:
And here is a late 1934 updated plan, with the five inch gun deleted, but the deck still ending short of the fantail:
Now, if the deck did not extend over the fantail, or the forepeak, it would be perfectly correct to say the overall length of the ships, and the overall length of the HULL proper, were one and the same. Here are the hull figures on the hull plan, indicating the OA length of the HULL is 809'9", and the length between perpendiculars is 770 feet (often misreported as 761 feet in erroneous sources. 761 was the light load WL length at 21 ft of draft. The design draft was 24 ft, and at design displacement the WL length was 770 feet, which is one and the same as the length between perpendiculars). This plan is longer than my living room, so forgive if this is too small to read clearly:
And here we have Yorktown's AS BUILT drawing, showing the real ship as she was finished:
And Hornet's stern:
Now, the piece de resistance!
Here is Hornet's flight deck plan, aft end. The figure is a little smudged, but in the real copy, it is easy to read. This is the full ramp end to ramp end measurement of Hornet's flight deck. The figure is 816 feet, 0 inches:
Now DANFS says Hornet was 809'9" overall. How could a ship that long have a flight deck that was 816 feet?!!!
Remember that 8'9" bow forepeak beyond the edge of the flight deck?
Add that 8'9" forepeak extension to the flight deck length of 816 feet and you get 824 feet 9 inches OVERALL LENGTH. Years ago, I had measured the flight deck on Webb Warships plans for CV-5 and got the exact figure of 816 feet, even though that number was mentioned NOWHERE. Yet, there it is on the corner of Hornet's deck plan.
(Sidebar. DANFS also erroneously lists Hornet as a separate class. This also probably dates from preliminary contract studies, when it had not been settled just what changes CV-8 would have, and it was never updated. All other USN offical documents, and the USN Historical Center web site all list Hornet, correctly, as a member of the Yorktown class. Anybody who has the plans can compare. Almost all her drawings are repeat CV-5/6 ones. Her changes were far less than seen between most Essexes. It is her pilot house and bridgework that make her look much more different than her actual structure underneath indicates.)
One last detail. The figure of 824'9" grew in CV-8 first, in February, 1942, to 827 feet 5 inches when 20mm tubs were added to either corner of her stern flight deck ramp. CV-6 got her first pair of 20mm ramp tubs just like Hornet's, in July 1942. After Eastern Solomons, she had her single tubs doubled up to a pair on each corner. Her length was 827'5" from July 1942. It is erroneously reported that she was lengthened from 809'9" to 827'5" in her Oct 1943 refit. What happened is her official dimensions were re-measured post refit, in view of her extensive changes, and somebody in WW2's vast beauracracy looked at original design figures from 1934, instead of her actual "as built" figures from 1938, and wrongly recorded that the ship grew 18 feet. Whoever did this will never be known, but I'm sure that scenario is how this goof came to be.
For those of you who watched the Battle 360 series on Enterprise, I was assisting them all the way through, beginning at episode 2. (I'm in the credits!) Anyway, I told the exec producer that the notion that Enterprise was lengthed in October 1943 was an utter falsehood, and laid out much of what you see here. He went with the CV-6.org figures anyway, and the series erroneously stated that Enterprise gained 18 feet in 1943. I told the CV-6.org webmaster in e-mails some years ago that the dimension chart on CV-6.org was all wrong on this. He still would not correct it. I guess official builder's plans, verified by "as completed" photos are not enough to convince him that the flight deck really did extend beyond the fantail by 15 feet.
Go figure!
Cheers,
Mike
PS, Some weeks back, I sent a package to the US Navy Historical Center with recommended corrections to DANFS and their website, with plans and more details than I could include here. We'll see if they act on it. Probably it is like fighting city hall.
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but, will give it alot of thought.