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Post by oldpop2000 on Mar 26, 2019 16:34:13 GMT -6
Hiya guys, I'm the builder of the armouredcarriers.com site. I just want to say ... I'm very happy to see this debate. It is exactly the informed exchange of opinions - based on the broad impact of doctrine, design and history - that I had hoped to promote some 15 years ago when I first started compiling the information that eventually made its way online. I'm sorry some of you feel my site is intentionally biased: I'm always happy to take directed criticism, examine it and address it where appropriate (tell me which part of which page, and give me some reasons and references: not sweeping motherhood statements, please). And I always try to provide what I assess to be the closest related comparisons, where possible (though even with apples v apples, it often means Granny Smith v Fuji). But it is inevitable that I will be accused of bias as I am attempting to present a case. A little background: I'm not British, nor do I live on the British Isles. I'm not a citizen of the United States, nor do I live in those states. I'm 6th generation Australian of mostly German heritage, with some Russian and Cornish thrown in. I'm not an academic. I initially had no intention of putting this online. I deliberately chose to write a narrative summary to encapsulate related first-person accounts and official documentation, be it supportive or critical. I very much regret not taking the footnoted approach as mentioned here, as - yes - I find I often have to dig through my books and transcripts to find the source. Chalk that down to ignorance at the outset. (I've since been steadily going back over articles to reduce this failing, and almost all side panels have their archive reference number or book source. And I have reference pages detailing the reference books I own, though it is due for a significant update) Like most Australian schoolkids, I grew up to stories and lessons about the Coral Sea and the Pacific Campaign. Like most Australian schoolkids, I became a big fan of the Essex and Iowa class ships that were the figureheads of that campaign. Like most Austrlaian schoolkids, I had no idea the British Pacific or Indian Ocean fleets existed after Singapore. My interest in the RN armoured carriers was only piqued when reading some of the books that came out in the 90s and 00s about USS Franklin and Bunker Hill. I'd only ever seen 'throwaway' mentions of the RN carriers and their experience - rarely more than two or three sentences. And most of them seemed to conflict in important areas of detail. This became doubly evident when watching online discussions. I tried to locate some in-depth sources, but found them - then - to be surprisingly rare. There was Friedman's mostly excellent British Carrier Aviation. But this was about the technical evolution of the ships and aircraft, not history or performance. Eventually I stumbled across Poolman's Illustrious. But most other accounts were fragmented, and spread across a variety of usually older books. So I started pulling them together for myself. And I became so annoyed at all the conflicting accounts that I ordered digital copies of the HMS Illustrious and HMS Formidable battle damage and after-action report archives from the UK National Archives so I could figure out what had actually gone on. Posting online attracted academic attention on both sides of the Atlantic. Extremely generous researchers have since volunteered some of their open access to the US and UK archives to continue to expand and broaden the content of my site. Which is why it has since grown to be the beast it has become. It is not finished. I'm finding it much harder than expected to find in-depth details about the design of USS Midway, including drawings and accounts of the extent of the armour on her flight deck. But I'm working on it slowly. This is 'just a hobby', after all. Again: I'm glad to see how much the debate has evolved since the time the essays of Slade and Worth were the only accessible material on the subject back in 2000. Keep it up. And I'll keep watching those discussions I find in order to find substantive details that will help add to the summaries of my site. Regards, armouredcarriers.com Hi Armoredcarriers.com: It is a real pleasure to have you on this forum. It is well run and everyone on here has some good information and ideas to offer. I really like your website, and have bookmarked it to use it as a source. I also have many books on aviation and surface ships along with naval strategy and doctrine. As to the USS Midway, I live in San Diego where she is parked. I've been on her at least twice. Here is the website and you could use the contract information to contact them for more information. I never worked on her, but I did work on seven US Navy carriers during my government career along with a host of aircraft. I've found the Norman Friedman has some good information on its design, construction and operations, but I suspect you have already tapped that source. The only suggestion for you is to remember that economics and geography played a large part in the decisions that the British government made in the interwar period. The US believed in an offensive type of naval war, the British defensive. Their carriers reflected that belief. You might want to explore some economic and geographic issues to provide some explanations for the choices that were made. The US welding technology was also better as was our materials. I don't have specifics though, but that might be another direction to go in. As to the Japanese, they seem to fall in between the British and the US. They however, had exactly same economic and geographical issues as Great Britain. Anyway, welcome and I hope we can stimulate your good work. www.midway.org/
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Post by bcoopactual on Mar 26, 2019 16:40:13 GMT -6
armouredcarriers , Welcome to the forum. Yours is an excellent website. Bravo Zulu. Just for the record, I'm #TeamGrannySmith.
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Post by dorn on Mar 27, 2019 0:32:41 GMT -6
Welcome to the forum, you site are excellent. I get a chance to interest in British carriers reading good book in my native Slavic language when I was young. There was not so much specification of carriers, more their performance in the Mediterranean, which is quite a task.
Reading you site get a lot of overall picture on carrier design, performance and all difficulty British has. Thanks a lot.
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imryn
Full Member
Posts: 156
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Post by imryn on Mar 27, 2019 6:37:29 GMT -6
Hi armouredcarriers and welcome to the forum. I have read your website and I am hugely impressed with the work you have put in. As far as I have been able to determine it is the only source of detailed information about the RN armoured carriers that draws together information about all 6 of the ships and presents it in a cohesive narrative. You have done a wonderful job of presenting the information in an approachable and beautiful format, and the narrative approach makes it very easy and entertaining to read, however (as you noted) the lack of footnotes does make it a bit more difficult when reading it from a scholarly perspective. At the end of the day, it is your website and obviously a labour of love for you, so you get to present it in whatever way you want and the rest of us should just be grateful that you have taken the time and effort to collect and present this information. My only real criticism centers around the terminology used. There is a fundamental difference between an armoured hanger and an armoured flight deck and yet in the website you use both terms at different times to describe the same thing, and this creates confusion as they actually describe two entirely different things that serve two different purposes that have an area of overlap. In the doctrine sections you describe in perfect detail the thinking that lead to the concept of the armoured hanger, and the construction methods used that resulted in the internal closed nature of the hanger, without mentioning that these construction methods were the same ones used to build Ark Royal. If you had started your narrative with the Ark Royal you could have high-lighted the differences that the change in threat appreciation and doctrine necessitated, and the changes and compromises that were necessary to meet the new threat. The Ark Royal and all six armoured carriers were built using the same construction technique; they were built with an internal hanger incorporated into the hull of the ship, meaning that the strength deck was the flight deck. Other contemporary navies were building ships with external hangers that were built as superstructure and the hanger deck was the strength deck. The decision to build the ships with internal hangers was made in the treaty environment of the 30's when any saving in weight was essential, and there was probably no other way of building the ships they needed within the tonnage limits. However, in hindsight it proved to be a questionable decision that introduced unexpected weakness into the ships hull. Thus, you do an excellent job of describing the concept and implementation of an armoured hanger, but in other parts of the website you refer to armoured flight decks without ever exploring or describing what that term means. In the context of your website it is clear that you are using it to describe the armour on the roof of the armoured hanger, but that is not the same thing as an armoured flight deck. An armoured flight deck serves a fundamentally different purpose to an armoured hanger; the latter is designed to provide protection for the aircraft stowed in the hanger, the former is to protect the integrity of the flight deck and allow the ship to continue air operations. The armoured hanger roof on the RN armoured carriers did serve the purpose of an armoured flight deck over the portion of the flight deck that it encompassed (the area of overlap i mentioned above) but crucially it did not provide protection for the forward and aft ends of the flight deck which are the critical areas for conducting flight operations. Thus, describing the RN armoured carriers as having an armoured flight deck is both incorrect and misleading. As far as I am aware the Midway class was the first carrier with an armoured flight deck. I am looking forward to reading that section of your website once you have completed your investigation, but from the limited information I have found it appears that the Midway class was essentially a scaled up version of the Essex class with the hanger deck as the strength deck, an external open hanger built as superstructure with an armoured flight deck on top. Despite being almost double the tonnage of the Essex class the airgroup size was only increased by about 30% and the ship had much lower freeboard than an Essex. From the limited information I have been able to see the trade-offs necessary to get a 3.5" armoured flight deck weren't worth it, but I will be very interested to read your conclusions. I find it interesting that the concept of the internal hanger, that proved to be so limiting in the RN carriers in WW2 eventually superseded the external hanger. It is hard to get accurate information but I believe that all the US supercarriers from USS Forrestal onward have been designed with an internal hanger and the flight deck as the strength deck. No other carriers have been subjected to the same level of attack as the RN carriers were in WW2 so it is impossible to make any meaningful comparisons as to the durability of the various different designs. What is clear to me, from your website and other sources, is that the RN armoured carriers were built to fulfill a doctrine that was predicated on a very specific set of circumstances that pertained to the RN in the mid 30's. By the time WW2 broke out that doctrine was already out of date and in particular technology had progressed in such a way as to invalidate large parts of it. The RN attempted to update the ships to reflect new technology and doctrinal changes with limited success, however constrained by their size and the limits that their basic design imposed were never able to create a satisfactory result. Looking at the historical record I don't think it was ever possible to build a carrier with a satisfactory armoured flight deck that could provide protection against aerial bombardment. The RN carriers had protection against 500 lbs bombs over part of their flight deck but they faced bombs 4 times that size. To provide armour that could protect against 2000 lb bombs over the entire flight deck just isn't practical on a ship that carries an effective airgroup, and by the time the threat was correctly defined (historically) the primary method of defense had evolved away from armour. I know that my opinion is not shared by some of the other forum members here, and I hope this post doesn't offend those who disagree with me.
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Post by dorn on Mar 27, 2019 8:39:14 GMT -6
As I understand difference between armoured deck and armoured hangar in case of Illustrious/Implacable class is the difference of whole and a part.
Several parts together creates armoured hangar:
- armoured (flight) deck - top (in case of these classes only part of whole flight deck)
- armoured sides of hangar - starboard/port
- armoured hangar deck - bottom
- armoured bulkheads - in this case doors (fore/aft)
So in case of bomb penetration the most important is armoured deck. After bomb penetrated this deck, than armoured hangar deck. How else do you describe only horizontal part on top of hangar which is armoured?. In case of near misses armoured sides of hangar is most important. It is the reason when somebody used "armoured (flight) deck" it does mean part of armoured hangar not the whole. I think that everybody here discussing this understands.
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Post by oldpop2000 on Mar 27, 2019 10:38:27 GMT -6
Let me see if I understand the unarmored/armored configurations. A. We have an unarmored deck and an open hangar. This would mean that the deck and hangar are part of the superstructure and have to be built in four sections because of hogging and sagging. B. We have an armored deck and an open hangar. This would correspond to the USS Midway. Same as the above. C. We have an armored deck and a closed hangar. This would be one British configuration and the deck and hangar bay hull, are part of the hull. D. We have an armored deck and an armored hangar. It could also mean a second smaller hangar bay below the first one. Again, it is part of the hull. On this configuration, we have an armored deck, armored hangar sides and an armored hangar deck with armored bulkheads. In comparison to the Yorktown class, the Illustrious hull and superstructure were lighter. The first two allow for more aircraft, as high as 120, the second two restrict the number of aircraft but with a partial deck park, you might get up to 55 aircraft on board. So, what do you think? Reasonable. Funny, all the years I worked on carriers, I never thought about any of this. This is great. Update: From Springstyle #3 - the design that led to the Midway shipscribe.com/styles/S-511/images/s-file/s511-42c.htm
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Post by jwsmith26 on Mar 27, 2019 12:20:07 GMT -6
Norman Friedman, in his book Carrier Air Power, provides an explanation for why the US Navy moved to enclosed hangars in the 50s.
"The new strategic situation of the late 1940s and the 1950s changed the conditions under which carriers would have to operate in wartime. The US Navy of the interwar period was essentially a Pacific navy; now it was an arctic navy. For example, hangar spaces had to be enclosed more effectively and heated, and indeed heating had to be provided for the flight deck operation. Deck wetness meant icing. Ordinary shipbuilding steel might crack in the extreme cold. Much rougher weather had to be expected, yet the carrier and her escorts would have to maintain very high speed in it; speed was, after all, the principle insurance against submarine attack. More than carrier hull design was involved: the demand for sustained high rough-water speed was perhaps the greatest factor forcing up the size of the task force escorts, which in time become frigates (DL) and then missile cruisers."
This book provides excellent coverage of the transition from prop planes to jets.
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Post by oldpop2000 on Mar 27, 2019 12:34:57 GMT -6
Norman Friedman, in his book Carrier Air Power, provides an explanation for why the US Navy moved to enclosed hangars in the 50s. "The new strategic situation of the late 1940s and the 1950s changed the conditions under which carriers would have to operate in wartime. The US Navy of the interwar period was essentially a Pacific navy; now it was an arctic navy. For example, hangar spaces had to be enclosed more effectively and heated, and indeed heating had to be provided for the flight deck operation. Deck wetness meant icing. Ordinary shipbuilding steel might crack in the extreme cold. Much rougher weather had to be expected, yet the carrier and her escorts would have to maintain very high speed in it; speed was, after all, the principle insurance against submarine attack. More than carrier hull design was involved: the demand for sustained high rough-water speed was perhaps the greatest factor forcing up the size of the task force escorts, which in time become frigates (DL) and then missile cruisers."This book provides excellent coverage of the transition from prop planes to jets. Ahem, here is a video of the openings on the port side of the USS Midway. All US carriers, have hangar doors leading to the lifts on the edge of the flight deck. That is also how we got electronic sets up to the hangar bay to install into the avionics rooms via the hall down the middle of the ship at aft end of the hangar bay #3. The bays can be sectioned off with a steel door. www.youtube.com/watch?v=774chLDRMTQHere is an image of one of the three hangars on the USS Nimitz. In the background, you can see the hangar door closing it off from the other hangars. if you look on the right side in the foreground, you will see box like structure. That is a RAMVAN, which would be outfitted with electronic test equipment and lifted to the ceiling. IT would be connected to the walkway along the top of the hangar. It was used to provide extra space of new test equipment for which there might not be enough room. They were easy to lower and move out the hangar doors to a truck. It would be moved to the avionics building of the base and work would be done on it. You could just do repairs up in van when it was attached to the ceiling.
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Post by axe99 on Mar 27, 2019 16:09:32 GMT -6
Love your work armouredcarriers, am a big fan of your site and consider it an important resource in this debate (and the best source for it) .
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Post by armouredcarriers on Mar 27, 2019 22:39:46 GMT -6
Thanks for your comments and directed criticism. Yes: I shall revisit my work to remove "armoured flight deck" and replace it with "armoured hangar". Again, the website represents an evolution of material over more than a decade. I ended with a better understanding of the terminology than I started. The problem is, as with most authors, I now often re-read my own words as what I wanted to say - instead of what it's actually saying. I have holidays soon, so I'll go through it as carefully as I can. The flight deck as a strength deck is a separate (though related) argument to the armoured hangar component. I recently added two new original documents detailing discussions between RN designers on that matter: www.armouredcarriers.com/opensided-versus-closed-hangars-in-aircraft-carrierswww.armouredcarriers.com/-document-2-opensided-versus-closed-hangarsI've not found any early primary source opinions expressing opposition to these views - yet. If and when I do, I assure you I will include them. USS Midway is at the moment presenting a real issue to me. Many sources say she has an 'armoured flight deck'. But these same sources say the same about Taiho. And Taiho had armour between the lifts, and on the lifts, but not between the bow and stern and the lifts. In essence, the same armour arrangement as HMS Unicorn (which was the only RN armoured carrier to armour its lifts). Also, USS Midway was very extensively rebuilt. What I am seeking - but have not yet managed to find - are builders diagrams of its original form. This will hopefully confirm the extent of the original armour, and the nature of its original hangar. Most books I have access to so far give only the broadest strokes of detail ... the same lack of detail that originally drove me to distraction about the Illustrious class and spurred the whole website in the first place!!!!
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Post by armouredcarriers on Mar 27, 2019 22:53:04 GMT -6
Just a quick note on the return to 'closed' hangars after World War II. They were not as 'closed' as the WWII armoured box hangar carriers. Even the Audacious-class (Eagle and Ark Royal) had deck-edge hangars cut into their sides.
But they were made to be airtight, as a countermeasure to nuclear fallout fears. Being 'gas resistant' was mentioned in the design discussions for the Illustrious class, but whether or not that was just thrown in for effect is anyone's guess.
PS: I'm not at all offended by opinions. But I generally only pay attention to them when they are backed by substantive arguments. Those arguments, when supported by examples, documents and case studies, can be utterly fascinating.
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Post by oldpop2000 on Mar 28, 2019 0:29:46 GMT -6
Thanks for your comments and directed criticism. Yes: I shall revisit my work to remove "armoured flight deck" and replace it with "armoured hangar". Again, the website represents an evolution of material over more than a decade. I ended with a better understanding of the terminology than I started. The problem is, as with most authors, I now often re-read my own words as what I wanted to say - instead of what it's actually saying. I have holidays soon, so I'll go through it as carefully as I can. The flight deck as a strength deck is a separate (though related) argument to the armoured hangar component. I recently added two new original documents detailing discussions between RN designers on that matter: www.armouredcarriers.com/opensided-versus-closed-hangars-in-aircraft-carrierswww.armouredcarriers.com/-document-2-opensided-versus-closed-hangarsI've not found any early primary source opinions expressing opposition to these views - yet. If and when I do, I assure you I will include them. USS Midway is at the moment presenting a real issue to me. Many sources say she has an 'armoured flight deck'. But these same sources say the same about Taiho. And Taiho had armour between the lifts, and on the lifts, but not between the bow and stern and the lifts. In essence, the same armour arrangement as HMS Unicorn (which was the only RN armoured carrier to armour its lifts). Also, USS Midway was very extensively rebuilt. What I am seeking - but have not yet managed to find - are builders diagrams of its original form. This will hopefully confirm the extent of the original armour, and the nature of its original hangar. Most books I have access to so far give only the broadest strokes of detail ... the same lack of detail that originally drove me to distraction about the Illustrious class and spurred the whole website in the first place!!!! I put a link to the Springstyles #3 drawing of the preliminary design dtd 22 September 1941. The drawing is the official drawing for the ship that eventually became the USS Midway. If you examine it, she had a 2 in. armored deck over hangar one, two and three. Hangar one was 220 ft. long, Hangar 2 was 132 ft. long and Hangar 3 was 200 ft. Long. This means that the armored deck was 552 ft. long which means it did not cover the whole ship. When built she was 900 ft. long, beam of 111 ft and a draught of 32 ft. Now does that answer the question. The drawing is what we would call a primary source document created by the BuShips.
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imryn
Full Member
Posts: 156
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Post by imryn on Mar 28, 2019 4:41:26 GMT -6
Let me see if I understand the unarmored/armored configurations. A. We have an unarmored deck and an open hangar. This would mean that the deck and hangar are part of the superstructure and have to be built in four sections because of hogging and sagging. No, this doesn't necessarily follow - internal or external hanger defines whether the hanger is superstructure or part of the hull. Open or closed hanger can be either internal or external. flight deck is slapped on top. Example of external open hanger with unarmoured deck = Essex
B. We have an armored deck and an open hangar. This would correspond to the USS Midway. Same as the above. Adding that the hanger is external, then yesC. We have an armored deck and a closed hangar. This would be one British configuration and the deck and hangar bay hull, are part of the hull. Adding that hanger is internal, then again yesD. We have an armored deck and an armored hangar. It could also mean a second smaller hangar bay below the first one. Again, it is part of the hull. On this configuration, we have an armored deck, armored hangar sides and an armored hangar deck with armored bulkheads. In comparison to the Yorktown class, the Illustrious hull and superstructure were lighter. An armoured flight deck and / or an armoured hanger can be built as either an internal or external hanger. Internal hangers can be two level (Ark Royal) so external hangers can probably be built that way as well (can't think of an example). The hanger roof, sides and bulkhead armour is obviously parts of an armoured hanger which can be built either internal or external. In Illustrious the internal hanger was used to make enormous savings in weight, so that despite the armour the hull was lighter. The same basic construction technique is used in USN supercarriers to this day, however the goal isn't to save weight but to provide enormous structural strength.The first two allow for more aircraft, as high as 120, the second two restrict the number of aircraft but with a partial deck park, you might get up to 55 aircraft on board. An internal hanger does somewhat limit the width of the available space as it sits inside the strength girder; an external hanger sits on top of the strength girder and can utilise the full width of the hull, and can even overhang if you want. The main reason for the smaller airgroups is the hanger length - Ark Royal 173m (upper) 137m (lower), Illustrious 139m, Implacable 139m (upper) 63 (lower), Essex 199m. Due to the weight of the armour the hanger was not built as long on the armoured ships as it was on the unarmoured ships. Hanger area directly equates to airgroup size even when deck parks are used (the parking area is generally above the hanger after all) so Ark Royal 5,690 sq m, Illustrious 2,638 sq m, Implacable 3,837 sq m, Essex 4,247 sq m.So, what do you think? Reasonable. Funny, all the years I worked on carriers, I never thought about any of this. This is great. Update: From Springstyle #3 - the design that led to the Midway shipscribe.com/styles/S-511/images/s-file/s511-42c.htm
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imryn
Full Member
Posts: 156
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Post by imryn on Mar 28, 2019 5:04:00 GMT -6
Thanks for your comments and directed criticism. Yes: I shall revisit my work to remove "armoured flight deck" and replace it with "armoured hangar". Again, the website represents an evolution of material over more than a decade. I ended with a better understanding of the terminology than I started. The problem is, as with most authors, I now often re-read my own words as what I wanted to say - instead of what it's actually saying. I have holidays soon, so I'll go through it as carefully as I can. The flight deck as a strength deck is a separate (though related) argument to the armoured hangar component. I recently added two new original documents detailing discussions between RN designers on that matter: www.armouredcarriers.com/opensided-versus-closed-hangars-in-aircraft-carrierswww.armouredcarriers.com/-document-2-opensided-versus-closed-hangarsI've not found any early primary source opinions expressing opposition to these views - yet. If and when I do, I assure you I will include them. USS Midway is at the moment presenting a real issue to me. Many sources say she has an 'armoured flight deck'. But these same sources say the same about Taiho. And Taiho had armour between the lifts, and on the lifts, but not between the bow and stern and the lifts. In essence, the same armour arrangement as HMS Unicorn (which was the only RN armoured carrier to armour its lifts). Also, USS Midway was very extensively rebuilt. What I am seeking - but have not yet managed to find - are builders diagrams of its original form. This will hopefully confirm the extent of the original armour, and the nature of its original hangar. Most books I have access to so far give only the broadest strokes of detail ... the same lack of detail that originally drove me to distraction about the Illustrious class and spurred the whole website in the first place!!!! I suggest looking further back for documents relating to the decision to use an internal hanger on the Illustrious class. Ark Royal was built with an internal closed hanger just like the later Illustrious class so there is a good chance that all of the debates over the pros and cons of that design took place when they were designing and building Ark Royal.
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Post by oldpop2000 on Mar 28, 2019 9:30:39 GMT -6
Here is D. K. Brown’s assessment in Nelson to Vanguard: Warship Design and Development 1923-1945.
The problem of finding primary sources for the Royal Navy is that they might not be available in digitized form. You would have to go to the Admiralty records to find the information. D. K. Brown's books have the best, or at least in my opinion, sources. He does reference other books by Friedman and others, most of which I have. So, there it is. Brown was very thorough ( he passed away some years ago), and was a Naval Architect for the RN.
Brown, D. K.. Nelson to Vanguard: Warship Design and Development 1923–1945 (Chatham's Distinguished Design) . Naval Institute Press. Kindle Edition.
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