Hawkins and Emerald class 8 inch conversions

[JFC Fuller]

I have been reading book about RN naval policy in the 1920s and came across a segment that reminded me of the proposed 1925 conversion of the Hawkins class to 8" guns* but it also added in an additional element in that Churchill apparently asked that the Emerald class also be considered for conversion to the then new 8 inch gun.

Does anybody know of anywhere where drawings of these proposed conversions have been published? Has anyone ever drawn such a conversion, for either class, using shipbucket or some other mechanism?

*details provided by smurf here: http://www.secretprojects.co.uk/forum/index.php/topic,19763.msg194148.html#msg194148

 

[Tzoli]

In Friedman's British Cruisers of two world wars and after book aka the British Cruisers book, he describes that the Hawkins class could had been equipped with 3 twin turrets, while there are enough space forward, the aft part is not wide enough to accommodate the standard twin 8inch turret of that time. A new turret would needed to be designed where the guns are closer to each other (something like on the USN Pensacola class) and also smaller ammo storage. Apart from the issue with a new turret (cost), smaller ammo storage (long fighting ability) the most drastic issue that the conversion would bought the ships displacement very close to the 10.000ton limit WNT allowed. The advantage would be that the 8inch guns are more powerful and had longer range than the 7,5inch guns not to mention a standardized heavy cruiser armament of 8inch guns could help with ammunition supply issues as the ordnance factories only need to produce 8icnh shells instead of 7,5" and 8".

Friedman also mentions a later design from 1938 where at least 2 ships be rearmed with 6x twin 5,25 gun turrets and a heavy duty catapult. He does not state how would this many turrets be cramped on the hull though...

 

[Abraham Gubler]

Vickers modified the Hawkins design for several 8" cruiser new build bids. Including for the RAN and the Spanish Armada. While not conversions of thd extant Hawkins ship these designs show what could possibly be done with an (extensive) rebuild.

 

[Tzoli]

While what you written is true the posted drawing is the predecessor or export design of the county class, not the Hawkins

 

[Abraham Gubler]

While what you written is true the posted drawing is the predecessor or export design of the county class, not the Hawkins

No it isn't. Look at the cross section of the hull (angled sides with bulges) and the plan of the engine rooms. This ship design is all Hawkins except for less belt (which isn't structural anyway) and the County turrets and inspired superstructure.

 

[Tzoli]

Sorry, but I've checked this hull with the Hawkins and the County (Kent class) classes and it is closer to the County than the Hawkins, but it can be seen it was evolved from the Hawkins. Turret placement is the same, 1st funnel is on the same location while on Kent the 2nd funnel is just between the 2nd and 3rd of this design. Which means this is a County preliminary and not an improved Hawkins. Improved Hawkins is the Emerald and that line ended there. Admirality started working new hull forms after WW1.

 

[Hood]

Data on Design 866 from Friedman 'British Cruisers'
Offered to Spain, cost estimate dated 6 June 1924, 590ft x 65ft x 40ft 10in x 17ft, 4x2 8in L/50, 6x1 4.7in HA, 4x3 24in TT, 120,000shp for 34.5kts, no belt armour, only deck armour 1.5in over magazines and machinery spaces "comparable to County".
867 was a slightly shorter version with 4x 4.7in; 868 had 6x2 8in on 565ft.
Before 866 from February 1924 were; 845 (3x3 8in), 847 (3x3 8in, County armour scheme) and 848.
There were other contemporary offerings to Spain; 875, 876P, 877, 878, 883 (a 'standard cruiser' offered to other nations too), 1143, 1143A, 904, 910 and 911.

All of these were from George Thurston's notebook, there is no doubt these were more influenced by the Counties than the Hawkins.

 

[Abraham Gubler]

A ship is a structure not an outer mould line. The design of the hull in cross section and of the engine and boiler rooms is as per the Hawkins not the County. They have stuck turrets on it and cut the belt weight to match but none of that makes it "closer" to the county. You can stick a fibreglass body styled like a Testarossa ontop of a Bettle but that doesn't mean you are driving a Ferrari not a VW.

 

[Tzoli]

Placement of engine rooms absolutely does not mean it derived from the Hawkins, it's a design choice probably multiple versions considered or this was the requirement of the Spanish Navy.
Also look at the date, this was designed in 1924, Kent was laid down in 1924 so why use an older cruiser for export when a newer were available?

 

[Hood]

The top-view shows the hullform to be almost identical to County, Hawkins had finer lines.
The Kents had a bulge too, the later London and Norfolk classes had the bulge removed to increase speed. I'll admit the hull is flared outwards more than Kent. I would say that Thurston (Vickers) mixed and matched from what designs the DNC was producing, so there was scope for a private firm to take the County and use layouts and structures the company was most familiar with to save design time. Vickers were successful in selling E Class derived designs to Spain and so these and Hawkins would have been a influence on the detail design.

 

[Abraham Gubler]

You guys are looking at the leaves and not the tru ks and roots. The County design had a high slab sided flush hull for high loadings per ton. It also had two boiler rooms and small scabbed on bulges. The Hawkins had a conventional hull form draft with quarterdeck cutaway and highly sloped sides with large integral bulges. It had three boiler rooms. Which of these two descriptions fits that of the attached export cruiser ship plan?

Its a Hawkins class derivative drawn at a time when the County class design was not even released for export nor had Vickers had enough access to it to regurge its core features for export if the were allowed to.

 

[JFC Fuller]

Its a Hawkins class derivative drawn at a time when the County class design was not even released for export nor had Vickers had enough access to it to regurge its core features for export if the were allowed to.

I have no interest in what the posted design was based on but I will just point out that there was no concept of "released for export" at the time. Vickers would create a design (ships and guns) then ask the RN and Foreign office if they would mind them making the sale.

 

[brutus]

You guys are looking at the leaves and not the tru ks and roots. The County design had a high slab sided flush hull for high loadings per ton. It also had two boiler rooms and small scabbed on bulges. The Hawkins had a conventional hull form draft with quarterdeck cutaway and highly sloped sides with large integral bulges. It had three boiler rooms. Which of these two descriptions fits that of the attached export cruiser ship plan?

Regarding the engineering differences between the classes: You're ignoring the advances in boiler design that took place between the construction of the Hawkins and County classes. The Hawkins class used Yarrow boilers. The County class were one of the first ships to use the more powerful Admiralty 3-drum boiler. As a result, the County class could produce more power than the Hawkins class with only 2/3 as many boilers. Hence the reduction in the number of boiler rooms.

However, a design for a foreign customer might use larger, heavier (but possibly cheaper) Thornycroft or Yarrow boilers as another option. If the customer already had ships that used those boilers, it could bring logistical advantages. Since the design on the previous page didn't have an armor belt to weigh it down, using heavier or less powerful machinery would be possible, especially if its cheaper. That may be the reason for the use of three boiler rooms.

Regarding the differences in hull design: The flush deck hull was dictated by the DNC to provide space for crew comfort for long periods at sea. A foreign customer might not need or want that. For the builder, the reduction in steel used would save them money, resulting in a lower bid or more profit on the ship.

Its a Hawkins class derivative drawn at a time when the County class design was not even released for export nor had Vickers had enough access to it to regurge its core features for export if the were allowed to.

In a word, baloney. Friedman, in The British Battleship 1906-1946, makes it clear that the DNC department drew up plans that were used to tender construction bids. One of the civilian yards (Vickers, Elswick, John Brown, etc.) would then turn those plans into construction plans that everyone, including the Royal Dockyards, would use for construction of the entire class. So Vickers would have plenty of knowldege about the County class design.

In his books on British battleships, cruisers and destroyers Friedman makes it clear that the British civilian yards were some of the most (if not the most) innovative yards in the world from the 1860's to the 1930's. DNCs Sir William White, Phillip Watts and Eustace Tennyson d'Eyncourt all spent some or most of their careers working in the civilian yards. They would be quite capable of designing warships all by themselves. So they don't need to copy any class of RN cruiser when creating designs for foreign powers.

 

[Tzoli]

Indeed for example Vickers offered a modified Nelson for Japan, to be precise for Rear Admiral Hiraga Yuzuru in 1924 for his request.

It is very possible or likely it was effected the 1929 pre Yamato Battleship design as well as some of the A-140 Yamato preliminary designs

 

[Volkodav]

Sorry, but I've checked this hull with the Hawkins and the County (Kent class) classes and it is closer to the County than the Hawkins, but it can be seen it was evolved from the Hawkins. Turret placement is the same, 1st funnel is on the same location while on Kent the 2nd funnel is just between the 2nd and 3rd of this design. Which means this is a County preliminary and not an improved Hawkins. Improved Hawkins is the Emerald and that line ended there. Admirality started working new hull forms after WW1.

Actually the Emerald is an improved D class fleet cruiser, the last iteration of the RNs North Sea oriented destroyer killing fleet support cruisers while Hawkins was evolved, through the "Atlantic Cruiser" and suggestions for HMAS Adelaide, from the earlier Town (Birmingham) trade protection cruisers. These separate evolutions are covered in some detail by Friedman in British Cruisers Two World Wars and After, the same is also stated in the Wikipedia entries for the two classes (yes I know Wikipedia has its issues but in this case it matches more reputable references).

 

[Abraham Gubler]

Regarding the engineering differences between the classes: You're ignoring the advances in boiler design that took place between the construction of the Hawkins and County classes.

No I’m not because they are irrelevant. We were talking about the hull design. Whatever boilers were used in this Vickers 8” ship they were arranged in three boiler rooms in the same place in the overall hull and of the same dimensions as the three boiler rooms of the Hawkins class. The County class had two boiler rooms. Therefore if this hull was based on that of the County class it would have required considerable redesign to be changed into three boiler rooms. Far more redesign than that which is needed to fit 8” turrets in place of the 7.5” shielded mountings in a Hawkins hull.

Regarding the differences in hull design: The flush deck hull was dictated by the DNC to provide space for crew comfort for long periods at sea. A foreign customer might not need or want that. For the builder, the reduction in steel used would save them money, resulting in a lower bid or more profit on the ship.

This is not actually true nor is the supposition made from it accurate. The County class design had a flush deck to as to distribute hull stresses over a larger structure. This reduced the loadings made on the structure and enabled it to be made from lighter steel providing a net saving in weight with a welcome increase in internal volume.

In a word, baloney. Friedman, in The British Battleship 1906-1946, makes it clear that the DNC department drew up plans that were used to tender construction bids. One of the civilian yards (Vickers, Elswick, John Brown, etc.) would then turn those plans into construction plans that everyone, including the Royal Dockyards, would use for construction of the entire class. So Vickers would have plenty of knowldege about the County class design.

This process you describe does not happen overnight. The time of this drawing was very close to when Vickers would have received the design for their County construction. One doesn’t just run these sheets through a mimeograph (no scanners back then) and then start making little changes to them for other customers. It takes a fair bit of time to understand the base calculations made for the design before you can start making changes.

They would be quite capable of designing warships all by themselves. So they don't need to copy any class of RN cruiser when creating designs for foreign powers.

So they didn’t copy the County? Or they didn’t copy the Hawkins? Vickers had already used the Hawkins for a few other offers before this drawing. Including a well-documented pitch to Australia. The Hawkins design was less than ten years old at the time and was far more attractive as an export design for most customers than the County. That is it had more protection while the County on the other hand was better suited for its trade protection role having excellent range and endurance.

 

[Abraham Gubler]

Hopefully some graphics will put this design heritage debate to bed. The main frame or midship section shows the structural DNA of a ship. If all else aligns (dates, access, people, etc) and they are similar then the ships are related. If they are different then they are not. Attached below is an image showing the sections of (left to right) HMS London (County class), Vickers 866 (the design under debate) and HMS Hermes (VIII). The London has to fill in for earlier Counties because I don't have a similar image for them. The only major difference is the loss of some small scabbed on bulges. Hermes is there to represent HMS Hawkins or the "Elizabethan" class. Again I have no midship section for this class but apparantly the Hermes was very similar, though of course modified to be an aircraft carrier.

As anyone should be able to see and comprehend there are no similarities between the 866 and the County except that they are both ships. The 866 and the Hermes are very similar not counting those areas that we would expect to be different between a carrier and a cruiser (flight deck, hangar, armour, etc). To look at this image of the main frame of a ship and say the Vickers 866 is a modified County would be like saying a human is evolved from a tiger based on analysis of their skeletons. The Hawkins is the 866's ape ancestor and not the County.

 

[Tzoli]

Then let me show you this:

from:
http://www.kbismarck.org/canarias.html

It is the midship cross section of the Spanish Canarias class heavy cruisers which were the export variant of the County class cruisers.
As you can see it is more similar to the Hawkins class hull yet it is a county derivative.

For example the Vickers offer for Australia:

as you can see the hull form is closer to the County you posted then the Hawkins it should be based on!

 

[Abraham Gubler]

Then let me show you this:

from:
http://www.kbismarck.org/canarias.html

It is the midship cross section of the Spanish Canarias class heavy cruisers which were the export variant of the County class cruisers.
As you can see it is more similar to the Hawkins class hull yet it is a county derivative.

Then it isn’t a derivative of the County class. No appeal to terminology can overwrite the reality of the structural design.

For example the Vickers offer for Australia:

as you can see the hull form is closer to the County you posted then the Hawkins it should be based on!

This was the second offer made many years after the original Hawkins derived offer.

If you don’t understand how structural engineering works you really shouldn’t be engaging in a structural engineering debate with someone who does. No amount of footnoting from half understood texts will help you.

 

[Arjen]

County class cruisers can be divided into three groups
- 7 Kent class, hull with torpedo bulges
- 4 London class, no torpedo bulges
- 2 Norfolk class, a development of the London class

Canarias and Baleares were modified Kent class ships.
Sources:
'The eclipse of the big gun - the warship 1906-1945', Conway's history of the ship, editor Robert Gardiner, 1992, p60-61
'Man o' war 1 - County class cruisers' by Alan Raven and John Roberts, RSV Publications, 1978, p1-11
<edit> fixed typos

 

[Arjen]

In 'Conway's all the world's fighting ships - 1922-1946', Conway, 1995, p411, Canarias and Baleares are described as modified versions of the Kent class, with a 4ft beam reduction and slightly increased length for better speed. Bulges explicitly mentioned.
<edit> From the same page: design change from Kents included three instead of two boiler rooms (as in reply#2's drawing), as well as raising the machinery power by 10,000shp.

The linked piece in Tzoli's reply #17 http://www.kbismarck.org/canarias.html tells much of the story about the Spanish cruisers.

 

[Tzoli]

Indeed.
What I've stated earlier that the Hawkins and Emerlad classes were the last representations of that hull form, it was mentioned in Friedman's British cruisers book.
The Counties and Leander classes were new hull forms meaning (as mentioned in Friedman's) that the RN (together with Vickers) abandoned the Hawkins design by the mid 20's around 1923/24.

 

[Abraham Gubler]

All of the above sources are wrong. Clearly the structural cross section of Canaris shows it is not related to the County. But rather is a Hawkins derived design. The term "hull form" does not apply to the structural design of the hull but only to outer mould line of the hull and can change from ship to ship within the class. Though of course they are closely related.

Just because it is written in Gospel does not dispel the truth before your very eyes.

 

[Arjen]

Quote from Willard C. Frank, Jr.'s article, linked to by Tzoli.

2. Design.

The new cruisers were designed by Sir Philip Watts as a modification of the British "County" class of Sir Eustace Tennyson d'Eyncourt, then under construction for the Royal Navy. Watts took a holder approach than did Sir William Berry with his London-Dorsetshire groups of the "County" class being developed at the same time.

My copy of 'Jane's Fighting Ships 1973-1974' describes Canarias as derived from the County class.

Every book I have read about Canarias and Baleares describes them as modified County class cruisers. When William Berry designed the London class, he integrated torpedo protection in the hull itself, removing the need for bulges. If you look at pictures of the Kent class, there is a noticeable flare to the ships' sides above the torpedo bulges. London class cruisers have no flare at all - they have a different hull.
<edit> added image from 'Man o' war 1 - County class cruisers'
<edit 2> added wiki image of HMAS Australia, showing her in October 1937.
<edit 3> replaced direct link to wiki image https://en.wikipedia.org/wiki/HMAS_Australia_%28D84%29#/media/File:HMAS_Australia_Oct_1937_SLV_straightened.jpg by smaller image as a kindness to those with narrowband connections

 

[Tzoli]

So you say that two the most well informed and trusted naval book writers Norman Friedman and Conway Maritime Press as well as other sources are wrong in this matter? I would not call this Gospel but straight facts!

 

[Abraham Gubler]

When William Berry designed the London class, he integrated torpedo protection in the hull itself, removing the need for bulges. If you look at pictures of the Kent class, there is a noticeable flare to the ships' sides above the torpedo bulges. London class cruisers have no flare at all - they have a different hull.

You’re right. I didn’t know this. I was going from a London sub-class body plan not an original County class body plan. The original County class design had the flare and bulge of the preceding Hawkins. You can see it in the attached graphic (Kent class body plan). It is only with the change in design from London that the blocky, flareless hull was adopted.

Which seems to blow my entire argument out of the water. However even with the County class having a Hawkins style flared hull, and the profile is virtually identical, it does have the higher and flush decked hull for lower structural loadings. The Vickers 866 does not have these features. It has near the same depth of hull as the Hawkins class (40’ vs 40’11”) and the same quarterdeck cutaway (located in the same frame forward from the stern).

So even though the Hawkins and Kent classes share the same main frame profile Vickers 866 is clearly derivative from the former not the later. Especially as if it was built with the County design with the depth reduced to 40’11” it would break in half thanks to the lower structural loadings inherent in the County design.

 

[Abraham Gubler]

So you say that two the most well informed and trusted naval book writers Norman Friedman and Conway Maritime Press as well as other sources are wrong in this matter? I would not call this Gospel but straight facts!

Well you just turned the whole enlightenment on its head. The whole point of science is that verifiable experimentation trumps whatever may have been previous opinion: no matter how weighty the opinion holders may have been. In this case the graphic I attached above showing the huge discrepancy between the London design and the Canaris design. If the London design had been accurate for the entire County class (it isn’t) then yes those sources would have been wrong. The whole point I was making is you should believe what your own eyes tell you is true not that is written down in some book. However of course I was working from a faulty understanding and the sources align with the evidence. In the case of the Canaris design. Not the Vickers 866.

 

[Arjen]

The whole point I was making is you should believe what your own eyes tell you is true not that is written down in some book.

I once handled an Airfix 1/600th HMS Suffolk model, with prominent bulges and flare to the sides. A few years later I bought 'Man O' War 1' with several images which show - if you're primed for it by, say, handling a model - Kent class cruisers with bulges.
"What your own eyes tell you" - what my fingers told me a long time ago of a model that might not have been accurate was nothing to be used as evidence in this discussion. It then took me three hours to find the wiki-image of HMAS Australia.
Image from http://www.middenheim.de/galerie/index2.php?nr=140

 

[Volkodav]

Interesting too and fro so I decided to pull out my copy of Friedmans British Cruisers Two World Wars and Beyond (2010), one of his more recent books so one would imagine one written from more evolved knowledge and understanding than his earlier books. There is a nice plan of Vickers design 924 (quite clearly the basis of the Canarias) on page 114 and a fairly informative description of the various cruiser proposals for Spain that led to the Canarias. Apparently there were many proposals including 6, 7.5 and 8" options with twin and even triple turrets, some with deck armour only, some with armoured belts. What was really interesting to me was three of the designs were offered to the RAN (I assume to build in Australia) as alternatives to the Kents built in the UK, including the evolved Hawkins with three triple turrets, a version with four twins and what was described possibly a repeat Kent as well as a smaller option with three twins.

The chapter on the treaty cruisers made it clear the County was to be a clean sheet design rather than a further evolution of the ultimate trade protection cruiser (Hawkins) or the ultimate fleet cruiser (Emerald), that if anything owed more to the Courageous Class Large Light Cruisers (hull form) than anything else. This is hardly surprising as the preceding chapter mentions that the starting point for a new trade protection or station cruiser was the Hawkins with consideration being given to something like the Courageous, five Courageous estimated to cost as much as eight Hawkins.

It seems some believe that the Hawkins and Emerald are related, they are not. The Hawkins is the ultimate evolution of the protected or light cruiser intended for global trade protection and station work, they owe most of their DNA to the Town Class and many of the concepts that ended up in the Hawkins were actually proposed for HMAS Adelaide, the last of the Towns. The Emeralds were the last iteration of the North Sea oriented, destroyer killer, flotilla leading, Scout Cruisers, intended primarily for fleet work that can be traced back to the Arethusa class, through the seven groups of C class and the Ds.

 

[Abraham Gubler]

Interesting too and fro so I decided to pull out my copy of Friedmans British Cruisers Two World Wars and Beyond (2010), one of his more recent books so one would imagine one written from more evolved knowledge and understanding than his earlier books. There is a nice plan of Vickers design 924 (quite clearly the basis of the Canarias) on page 114 and a fairly informative description of the various cruiser proposals for Spain that led to the Canarias. Apparently there were many proposals including 6, 7.5 and 8" options with twin and even triple turrets, some with deck armour only, some with armoured belts. What was really interesting to me was three of the designs were offered to the RAN (I assume to build in Australia) as alternatives to the Kents built in the UK, including the evolved Hawkins with three triple turrets, a version with four twins and what was described possibly a repeat Kent as well as a smaller option with three twins.

You are no doubt likely to be interested in this thread:

http://www.secretprojects.co.uk/forum/index.php/topic,19763.msg194148.html#msg194148

Which details some of the Codock offerings for the Australian treaty cruiser build.

Tzoli has also drawn a much better resolution version of the first Codock/Vickers offer (the image in the Codock book is very low res):

http://www.secretprojects.co.uk/forum/index.php/topic,19710.msg191416.html#msg191416

With 9x8" and 12x5" (5.2"?) in casemates and a deep belt (2" above 3") plus two protective decks (each 1.5") it would have been a much better gunship for the RAN in WWII. Six quick firing 5.2" guns per beam would have been very welcome in some of those close in night fights with the Japs.

 

[Tzoli]

Interesting too and fro so I decided to pull out my copy of Friedmans British Cruisers Two World Wars and Beyond (2010), one of his more recent books so one would imagine one written from more evolved knowledge and understanding than his earlier books. There is a nice plan of Vickers design 924 (quite clearly the basis of the Canarias) on page 114 and a fairly informative description of the various cruiser proposals for Spain that led to the Canarias. Apparently there were many proposals including 6, 7.5 and 8" options with twin and even triple turrets, some with deck armour only, some with armoured belts. What was really interesting to me was three of the designs were offered to the RAN (I assume to build in Australia) as alternatives to the Kents built in the UK, including the evolved Hawkins with three triple turrets, a version with four twins and what was described possibly a repeat Kent as well as a smaller option with three twins.

You are no doubt likely to be interested in this thread:

http://www.secretprojects.co.uk/forum/index.php/topic,19763.msg194148.html#msg194148

Which details some of the Codock offerings for the Australian treaty cruiser build.

Tzoli has also drawn a much better resolution version of the first Codock/Vickers offer (the image in the Codock book is very low res):

http://www.secretprojects.co.uk/forum/index.php/topic,19710.msg191416.html#msg191416

With 9x8" and 12x5" (5.2"?) in casemates and a deep belt (2" above 3") plus two protective decks (each 1.5") it would have been a much better gunship for the RAN in WWII. Six quick firing 5.2" guns per beam would have been very welcome in some of those close in night fights with the Japs.

Ahh yes, maybe I should re-draw it to my current standard

 

[Volkodav]

Very interesting, the hull section shown in the Vickers plan appears to be more London (no bulge, flare, or armour belt) than Kent or Hawkins so is likely one of the "Spanish" designs mentioned by Friedman.

It appears more and more that it is near impossible to state with any certainty that many of these unbuilt export designs are based specifically on a particular existing class, rather they seem to mix and match characteristics as required.

 

[JFC Fuller]

It appears more and more that it is near impossible to state with any certainty that many of these unbuilt export designs are based specifically on a particular existing class, rather they seem to mix and match characteristics as required.

Absolutely, in fact brutus hit the nail on the head earlier in the thread when he said this:

DNCs Sir William White, Phillip Watts and Eustace Tennyson d'Eyncourt all spent some or most of their careers working in the civilian yards. They would be quite capable of designing warships all by themselves. So they don't need to copy any class of RN cruiser when creating designs for foreign powers.

I would go further, these guys read the same journals, went to the same conferences and probably attended the same clubs in addition to often ending up seeing or even working on each others designs. There was considerable cross-pollination simply from them all working in the same professional community but ultimately they were smart enough to be able to design a warship specifically to the needs of a customer.

 

[Volkodav]

It appears more and more that it is near impossible to state with any certainty that many of these unbuilt export designs are based specifically on a particular existing class, rather they seem to mix and match characteristics as required.

Absolutely, in fact brutus hit the nail on the head earlier in the thread when he said this:

DNCs Sir William White, Phillip Watts and Eustace Tennyson d'Eyncourt all spent some or most of their careers working in the civilian yards. They would be quite capable of designing warships all by themselves. So they don't need to copy any class of RN cruiser when creating designs for foreign powers.

The other thing that many don't automatically realise in this day and age of 3D modelling packages, CAD, the various Adobe products, Photoshop etc. is that each sketch, each design, pretty much had to start from scratch as there was no easily available digital format to pull up and start playing with.
I would go further, these guys read the same journals, went to the same conferences and probably attended the same clubs in addition to often ending up seeing or even working on each others designs. There was considerable cross-pollination simply from them all working in the same professional community but ultimately they were smart enough to be able to design a warship specifically to the needs of a customer.

 

[Tzoli]

Here is Design X heavy cruiser for Spain from the Hiraga archive:

The exact Vickers design number is unknown but based on length and armament there are a few possibilities from which proposal it was modified from

Design 1074 a heavy cruiser proposal for Australia, armament and length are the same except tonnage was 10.750tons from 1923
Design 845 a heavy cruiser proposal for Spain, armament and length are the same except tonnage was 10.500tons and engine power was 120.000shp from 1924
Design 848 a heavy cruiser proposal for Spain, armament and length are the same except tonnage was 10.500tons and engine power was 135.000shp from 1925

 

[Tzoli]

And another one, an export county type:

 

[Volkodav]

Came across something that may be of relevance to the earlier discussion on whether drawings were based on the Counties or Hawkins.

In the chapter on the evolution of the G3 battlecruiser there is an explanation of why they decided on the particular turret arrangement with two forward and one between the bridge superstructure and the funnels. Basically the concern was that fire from forward of the ship could potentially plunge down through the funnels and carry on through the boiler room bulkhead and into the aft magazine, moving the machinery aft of the magazine removed this risk.

Now for the relevant bit, there is a reference note to this description that states that DNC was extremely unimpressed when Vickers submitted their new battlecruiser design for review before patenting it. This was because the side elevation and deck arrangement was virtually identical to the inhouse design Admiralty had just signed off, with one significant difference, the machinery was still forward of the aft magazine with the funnels being trunked around the magazine/turret to the new aft location. The conclusion was that elements of the Admiralties design had been leaked to Vickers but not including the internal arrangements or the reasoning behind them.

Reading between the lines Vickers appears to have had some access to Admiralty work but not to any real detail which probably explains why these drawings posted earlier have the appearance of the Kents etc. but the internal arrangements of the earlier Hawkins. They likely we able to discover the basic layout and external appearance of the new designs but not the internal arrangements of magazines, machinery, bunkers, torpedo protection etc. Dare I suggest (tongue slightly in cheek) a bit like some of the Chinese car design knock offs, look s exactly like a Japanese or Euro design but is anything but, and far less advanced under the skin.