A Royal Navy for the Far East 1942 Onwards

[Siberia]

For the UK, the submarine flotilla wouldn't have been pulled from Singapore, giving much better reconnaissance of Japanese harbours.

Having the T class boats available is going to create some major changes as they were one of the main legs of what the UK was expecting to use to counter Japan. IIRC the Royal Navy some war games post-war to look at how things might have gone and it was not good for the Imperial Japanese Navy.

 

[EwenS]

Having the T class boats available is going to create some major changes as they were one of the main legs of what the UK was expecting to use to counter Japan. IIRC the Royal Navy some war games post-war to look at how things might have gone and it was not good for the Imperial Japanese Navy.

In Sept 1939 the 4th Submarine Flotilla based in Hong Kong and Singapore had 13 O/P/R class built in the late 1920s / early 1930s specifically for action against the IJN. There was also 2 Porpoise class minelying subs with another en route (it was turned back to Britain on the outbreak of war in Europe). They had the use of the depot ship Medway which refitted at Singapore 1939/40. All these vessels were withdrawn from the Far East between 3 Sept 1939 and the outbreak of war with Italy in June 1940.

The T class were the intended successors to the O/P/R classes. The first vessel Triton was ordered under the 1935 Programme and completed in Nov 1938. Only 3 completed before the outbreak of WW2 with another 4 by the end 1939, 7 in 1940 and 6 in 1941. These were from the 1935, 1936, 1937, 1938 and 1939 War Programmes. Broadly enough to replace the O/P/R classes on a one for one basis. But 5 were lost before war with Japan broke out.

The next subs in the Far East were 2 T class dispatched from the Med to Ceylon in late Dec 1941 and early Jan 1942.

 

[DWG]

Having the T class boats available is going to create some major changes as they were one of the main legs of what the UK was expecting to use to counter Japan. IIRC the Royal Navy some war games post-war to look at how things might have gone and it was not good for the Imperial Japanese Navy.

Even without the Ts on top, the South China Sea was the environment the Odins, Parthians, and Rainbows were designed for, and in this scenario 4th Submarine Flotilla would have remained on station.

 

[NOMISYRRUC]

Part of Post 62.

At some point I must work out how many FAA units there might have been in 1942 based on peacetime plans. I have a sneaky feeling there would have been more spaces in carriers than the FAA actually had units to equip them.

The Number of Aircraft

504 first-line aircraft in the equivalent of 42 squadrons by 31st March 1942 according to RAF Expansion Scheme F of 1936, which was approved by the Cabinet on 25.02.36.

Page 369 of "Grand Strategy, Volume 1, Rearmament Policy" says the FAA was to have a total of 1,954 aircraft on 31.03.42 as follows:

• 490 first-line aircraft;
• 490 aircraft Immediate Reserve (IR) - that is 100% of the first-line strength;
• 490 aircraft War Reserve (WR) - that is 100% of the first-line strength;
• 484 aircraft for training purposes.

They would be operated by 8,700 RN personnel, excluding reservists and trainees.

IIRC (and I'm confident that I do) the 504 first-line aircraft were to consist of 360 carrier aircraft in 30 squadrons and 144 catapult aircraft in the equivalent of 12 squadrons. Unfortunately, I don't remember where I read it, so I can't quote the source.

However, I do have copies of Cabinet Papers from late 1937, saying that the RN had increased its requirement to 650 first-line aircraft in 50 squadrons, which I think is a rounding of 648 aircraft in the equivalent of 54 squadrons. That's because the same documents say the previous scheme was for 500 aircraft in 40 squadrons, which is obviously a rounding of 504 aircraft in the equivalent of 42 squadrons.

Unfortunately, the Cabinet Papers don't say what the mix of carrier and catapult aircraft was. I don't know what the required number of backing aircraft was either. However, based on the previous scheme it would have been 650 IR, 650 WR and 650 for training for a grand total of 2,600 aircraft.

The Types of Aircraft

The Air Branch (which was the official title of the FAA between 1939 and 1952 IOTL) would have been stuck with the types that were in service or about to enter service in September 1939 IOTL. Therefore, the fighters would have been Fulmars, Rocs, Sea Gladiator and Skuas, the strike aircraft would have been the Albacore and Swordfish and the catapult aircraft would have been the Walrus.

There would have been no combat experience between September 1939 and December 1941 to tell the Admiralty that its doctrine was faulty. So no Sea Hurricanes & Seafires.

Furthermore, as the British Aircraft industry wasn't overloaded due to not being at war for the previous 27 months and having to give priority to the needs of the RAF, no American carrier aircraft like the Martlet/Wildcat.

IOTL the first flight dates of the next generation of naval aircraft were;

07.12.40 Fairey Barracuda.​

27.02.42 Blackburn Firebrand.​

22.12.42 Fairey Firefly.​

06.02.43 Supermarine Type 322 "Dumbo".​

23.09.38 Supermarine Sea Otter.​

Firefly and Firebrand were intended to replace the fighters, the Barracuda and Albacore was intended to replace the Albacore and Swordfish, the Sea Otter was intended to replace the Walrus. ITTL the Sea Otter probably comes into service before 07.12.41 and I've no idea how 27 extra months of peace effects the development of the others. All I can say with some confidence is that the Barracuda probably goes into service with the Exe rather than the Merlin.

Note: First flight date of Fairey Barracuda corrected 04.05.25. See Message 97 by @DWG and Message 99 by me.

 

[EwenS]

June 1939 Minutes of meeting held by Fifth Sea Lord responsible for Naval Aviation.

Fairey Hayes - Swordfish to be followed by Albacore with production of 400 of the latter expected to complete by Aug 1941.

Fairey Stockport - Fulmars commencing about Nov 1939 and completing about March 1941, to be followed immediately by S.24/37 (Barracuda). Latter expected to complete by April 1942.

Supermarine Woolston - Walrus expected to complete by Jan/Feb 1940. To be followed by Sea Otter completing Jan 1942.

Production rates expected to be Fulmar, 20 per month, Swordfish, Albacore & Barracuda 35-40 per month, Walrus / Sea Otter, 8 per month. In war Air Ministry expected rates could be doubled.

At that point the new fighters were being designed to Specs N.8/39 (two seat fighter replacement for Fulmar) and N.9/39 (turret fighter replacement for Roc). All change in Dec 1939 using war experience to date. Result - selection of Firefly in early 1940 & single seat Firebrand. Latter was being driven by need to defend RN shore bases as the RAF were otherwise engaged after outbreak of war.

 

[NOMISYRRUC]

Link to the opening post.

For what it's worth I think His Majesty's Government would still be aiming for the following fleet by the middle of the 1940s.

82 Submarines (of which 7 could be over-age).​

20 Capital Ships.​

14 Aircraft Carriers.​

100 Cruisers (of which 15 could be over-age).​

22 Destroyer Flotillas (of which 6 could be over-age).​

226 Minor War Vessels.​

That was the "Two-Power Standard Fleet" of April 1937 that the Admiralty thought was required to fight a war against Germany and Japan at the same time and includes the naval forces of the Dominions and India as well as the Royal Navy proper.

 

[NOMISYRRUC]

This is how the requirement for 20 capital ships was calculated.

Capital Ship Strength.
6. Japan at present possesses 9 capital ships to our 15, and after 1940 her strength will become uncertain as she will probably not scrap any of her existing capital ships when she completes new vessels, which she can lay down after the 31st December, 1936.

7. When operating in the Far East our ships are far from their main repair facilities and sources of supply and have only the facilities of Singapore to rely on. The Japanese fleet, on the other hand, has its full home country resources available close at hand. These facts in themselves are equivalent to an advantage of two capital ships to Japan since at an average moment we could not rely on less than 2 ships being absent.

8. On the other hand, the stakes at issue in the event of a fleet action would be greater for Japan than for us. A British defeat would imperil our interests in the East: a Japanese defeat would imperil her home country. Thus, to achieve our object of acting on the defensive and serving as a deterrent against any threat to our interests in the East it is necessary that our capital ship strength should be such that Japan's chances of obtaining victory in a fleet action would be so slight that she would not seek one. This condition should be achieved if at our average moment we could meet the full Japanese capital ship fleet with a force less in strength than that fleet by one capital ship.

9. When allowance is made for our restricted repair facilities, which are referred to in paragraph 7, it follows that, to avoid at any time being inferior in ships available by more than one capital ship, we must have in the Far East a margin of one ship in excess of the Japanese total.

10. The strength of the German fleet is now calculable, since it is fixed at 35 per cent, of our own. The strategical situation in a future war with Germany must in general be similar to that which prevailed in the last war and while the German fleet would be likely to spend most of its time in harbour the initiative as to when it came out to dispute our control would rest with Germany. It follows that, as in the last war, we must be ready at our average moment to meet the German fleet at its selected moment. Home waters being our vital area in a way that the Far East never can be, it is essential that this margin shall be sufficient for all contingencies. The margin is composed partly of the superiority necessary to give reasonable certainty of success in battle and partly of that necessary to maintain our normal programme of docking. The proper minimum to meet these contingencies is a superiority of 3 ships.

11. The German capital ship fleet does not, unfortunately, correspond numerically to an exact 35 per cent, of our own, since its size is calculated on a total tonnage basis and the earlier German capital ships built and building are less than the maximum unit size. Thus, while our strength remains at 15 capital ships, 35 per cent, ought to give Germany only 5 ships. She will in fact have 6, assuming that the 3 " Deutschland " class are ultimately replaced by one large ship.

Thus, our capital ship strength in Home waters should not be less than 9 ships to six of Germany.

12. When this force is added to the force required in the Far East to meet the existing Japanese strength, we arrive at a total of 19 capital ships. This total would automatically allow Germany a further increase to 7 capital ships, which in its turn raises our number to 20.

13. With the proposed new standard it is clear that as the German strength is fixed at 35 per cent, of our own, both our strength and that of Germany will progress in proportion to the Japanese strength.

14. The capital ship strength required can be worked out mathematically, but, for practical purposes, our requirements to meet the conditions detailed above can be expressed as "1½ times the Japanese strength + 6 ships," or, in tabular form, as follows : —

​

Source:

• "APPENDIX TO ENCLOSURE - Calculation of the Size of Fleet required under the Proposed New Standard of Naval Strength".
• The enclosure being a Memorandum by the First Lord of the Admiralty called “A New Standard of Naval Strength”.
• Which was an enclosure to the Cabinet Paper, “Defence Expenditure in Future Years – Interim Report by the Minister for Co-Ordination of Defence”, dated 15th December 1937.
• National Archives Catalogue Reference: CAB/24/273 Image Reference: 0041

 

[NOMISYRRUC]

This is how the requirement for 14 aircraft carriers was requested.

Aircraft Carrier Strength.
15. The functions of naval aircraft are both strategical, such as reconnaissance for the fleet or for vessels operating in direct defence of trade, and tactical, such as attack on enemy vessels with torpedoes or bombs, observation of the gunfire of their own fleet, laying smoke screens, and attack on enemy aircraft.

Without aircraft a navy would be at a great disadvantage if opposed to a navy which possessed aircraft, but, apart from this, the existence of land aircraft, including possibly airships, capable of reconnoitring for enemy vessels to a considerable distance off the coast and attacking them when located renders the provision of naval aircraft a necessity in order to enable a Naval Power to carry out operations near an enemy's coast.

16. Although many countries, including ourselves, are fitting capital ships and cruisers to carry several aircraft, this method cannot provide either the numbers or types necessary, nor would it meet requirements in other respects, since the aircraft that have to be catapulted off ships may not be able to be recovered.

The aircraft carrier, designed primarily to enable aircraft to be operated from her as a floating aerodrome, is consequently an essential requirement in a modern fleet.

17. During the last 15 years our aircraft carrier tonnage has been limited by treaty, and the limits accepted allowed only for the maintenance of the aircraft carriers required for work with the Main Fleet with only a margin of possibly one ship for other duties. It has consequently not been possible for the Admiralty to provide aircraft carriers for employment on the trade routes to assist our cruisers and armed merchant cruisers in the protection of trade. Plans have been drawn up for the conversion of merchant ships into aircraft carriers after the outbreak of war, but this work would take about 12 months to complete.

18. With the end of quantitative limitations it is possible to give consideration to the construction of aircraft carriers for trade protection, and £2,060,000 was included in the new construction estimates put before the D.P.R. (D.R.) Committee (D.R.C. 37, Schedule 1, Appendix 1) for this purpose. The question of the possible reaction of the building of these vessels on our cruiser requirements is dealt with in paragraph 38 below.

19. Consequently, our aircraft carrier requirements must now be divided into those for work with the Main Fleet and those for trade protection.

20. Japan has 4 aircraft carriers built, 1 building and 2 projected. She also possesses 2 seaplane carriers built and 3 building or projected. In her own waters she has the great advantage of a chain of air bases in her islands which would enable her to keep a very large area under observation by shore-based air reconnaissance.

21. For offensive operations against Japan it would therefore be necessary for our fleet to possess a sufficient number of aircraft carriers. For the defensive role visualised in the new standard of naval strength, which need not necessarily involve operations near to Japan, it will only be necessary to provide our fleet with the carriers needed to maintain an adequate reconnaissance and a striking force of reasonable strength. It will also be necessary to make due allowance for docking and refit. It is considered that 4 carriers would meet these requirements.

22. In Home waters, Germany will be allowed 35 per cent, of our total carrier tonnage. Although we expect some assistance in the North Sea from shore-based aircraft, this is equally true of Germany, and it is not unlikely that the opposing land-based air forces will tend to some extent to cancel one another out so far as naval operations are concerned. It would not therefore be safe to accept an appreciably weaker carrier force with the Home Fleet than that possessed by Germany. To avoid this, provision is needed for not less than 4 aircraft carriers in Home waters.

23. The number of carriers suggested for the two main fleets must be regarded as tentative. By arguing on theoretical lines it is possible to arrive at much higher totals, and, if in the coming years all the claims now being made for aircraft are substantiated, it may become necessary to provide for greater strength in carriers. Alternatively, technical progress in aircraft may enable shore-based squadrons to perform some of the fleet duties for which we rely at present on carriers. Another factor the significance of which remains to be proved, is the adoption by the British navy of armoured carriers. The immediate effect of this is to give us only half as many aircraft for a given tonnage as are obtainable using carriers of the unarmoured type.

24. The use of carriers on the trade routes is a matter in which little experience is yet available, but a minimum of 5 is suggested herein for operations in conjunction with our cruiser forces. This number of 5 must remain open to review, and experience will very probably show that one aircraft carrier per cruiser squadron operating on trade protection work is required. It is hoped that by the building of these aircraft carriers for trade protection, an economy in the number of cruisers required can be effected.

25. In addition to the above, at least one large aircraft carrier must be retained for training duties in both peace and war. This vessel can be over-age.

​

26. The position is complicated, however, by the fact that we shall possess for many years a number of unarmoured carriers, which, though not at all satisfactory for fleet work, have a good aircraft capacity and cannot reasonably be discounted. They will include the Ark Royal, which is not yet complete and which will carry no less than 72 aircraft. It is accordingly proposed to accept 12 carriers, for whom aircraft and personnel shall be provided, and to retain 3 of our existing carriers in reserve at long notice. No personnel or equipment will be provided for the latter, but they will be available to bring forward in the event of war.

It comes from the same source as the calculation of capital ship requirements in Message 87.

 

[NOMISYRRUC]

This is how the requirement for 100 cruisers was calculated.

Cruiser Strength.
27. The need for a large number of cruisers is no new requirement, and it is not based on the imminence of a war threat, as may be seen from the numbers which we have possessed at various periods in the past, e.g.

​

28. For a war against Japan or against a single European Power, our cruiser requirements have, on many occasions in the past, been stated to be a minimum of 70, and then only on the assumption that arrangements have been made for the rapid conversion of a number of merchant ships (74) to armed merchant cruisers on the outbreak of war.

This requirement of 70 has been made up of:—

25 for work with the Main Fleet.​

45 for control of trade.​

The figure of 25 has been arrived at by the need for equality with the enemy cruiser strength in the war area (since the enemy at his given moment may always concentrate his cruisers with his fleet) and the strength of the battle fleets.

It has also been assumed in these past calculations that the Japanese cruiser strength would be subject to agreed quantitative limitation.

The figure of 45 for control of trade has been based on the assumption that a serious threat to our trade is unlikely to arise in more than one ocean at the same time.

29. Under the new standard of naval strength the assumptions on which both the above figures were based require revision. Firstly, two enemy main fleets now have to be taken into account, and, secondly, a serious threat to our trade may arise simultaneously in the Atlantic and in the East, as Germany and Japan, situated at the opposite sides of the earth, may both concentrate on attacking it.

Cruisers with the Main Fleets.
30. The cruiser strength required with a battle fleet is dependent partly on the size of the fleet, and partly on the enemy's cruiser strength. Japan has at present 33 cruisers and she may increase this number in the future. To enable our battle fleet to act in the Far East as required by the new standard of naval strength we can accept a somewhat smaller cruiser strength than that which would be required for "an offensive strategy against Japan, and so long as Japan does not add to her present numbers, a strength of 25 cruisers should be sufficient.

Included in this strength is a small margin to allow the undertaking of small offensive operations with a view to causing dispersal of Japanese forces.

31. It is difficult to know exactly what Germany's intentions with regard to cruiser building are, as there is provision in our agreement with her for a certain transfer between various categories. It appears reasonable, however, to assume that Germany may have 20 cruisers in all in 1942. Thereafter she has the right to increase further if and when we exceed 60 under-age cruisers. Even if no transfer from other categories takes place, Germany could have 35 cruisers if and when we reach the proposed new total of 100 (see paragraph 39 below).

32. Until we know what Germany will build it is not practicable to make an exact estimate of the cruiser strength we shall require with the fleet in Home waters in a future war with that country, but the number of 30 is assumed for the present, and is certainly not excessive when the need for refits and dockings and the experience of the Great War are borne in mind.

33. The total strength required with the main fleets in war areas may consequently be estimated as:—

​

Cruisers for Control of Trade.
34. Cruisers and other vessels employed on the control of trade may be employed either as convoy escorts or on patrol of focal areas, &c, where the threat of attack is not such as to call for convoy. In addition, in each area certain cruisers will be required to operate against enemy trade and to round up enemy raiders.

35. Further, in certain areas the convoy escorts may have to be vessels with a specially powerful A/A armament to protect our shipping from air attack in the event of an enemy adopting unrestricted warfare from the air, against which there is at present no international agreement to correspond with the rules for the conduct of submarine warfare contained in Part IV of the London Naval Treaty.

Even if agreement is reached on this subject in the future, it will remain a potential menace, and the Admiralty are, therefore, taking steps to equip a proportion of our cruisers with the necessary special A/A armament.

36. The number of 45 cruisers for trade work, which has been put forward in the past took no account of the need for A/A escorts, and assumed that convoy would only be required in one ocean at a time, e.g., in the Indian Ocean. (The method of protection by convoy requires considerably more ships than that of patrol, but, of course, affords better protection.)

37. Under the new standard of naval strength it is necessary to make provision against an attack on trade by Germany and Japan at the same time.

This would necessitate putting convoy into force in both the Indian and Atlantic Oceans. On the face of it this would clearly call for far more than the 45 cruisers required for the Japanese threat above. Exactly how many more is, however, difficult to assess, because the estimate of 45 allowed for 10 cruisers in the Mediterranean and home waters, which latter become merged in the large force of cruisers allocated to the Home Fleet under the new standard proposals.

38. It is hoped, moreover, that the provision of aircraft carriers to co-operate with the cruisers on the trade routes will lessen considerably the chance of a hostile raider escaping detection. This, in turn, should mean that fewer cruisers will be needed to safeguard a given area. Pending more accurate knowledge of the efficiency of a combination of cruisers and carriers on the trade routes (which is to be tested by special exercises), the Admiralty are prepared to accept the same figure of 45 cruisers for trade protection as was originally contemplated for war with Japan alone.

39. The total cruiser strength necessitated by the new standard of naval strength is, therefore, as follows:—

​

40. Of this total of 100 it is considered that approximately 15 could be over-age, leaving 85 under-age cruisers to be maintained. Ultimately, this would involve an annual building programme of 4 ships, with a 5th ship every leap year.

This comes from the same source as Messages 87 and 88.

 

[NOMISYRRUC]

This is how the requirement for 22 flotillas of destroyers was calculated.

Destroyer Strength.
41. Our total destroyer requirements can be divided into those which form part of the Main Fleet and would be employed tactically with the fleet in battle, and those employed on local defence, escort or patrol work. The former must all consist of under-age destroyers, but a proportion of the latter, particularly those employed on local defence and A/S escort, can be over-age vessels.

Requirements for the Eastern Fleet.
42. As explained in paragraphs 6-14, Capital Ship Strength, a battle fleet of 10 ships is visualised in the Far East. About 5 flotillas would ordinarily be required for tactical employment with a fleet of this size, but, as with cruisers, the actual destroyer force needed is partly dependent on that of the enemy.

Since Japan has 75 destroyers (i.e., 8½ flotillas by our reckoning) building and projected exclusive of over-age vessels, it is considered that we should need not less than 7 flotillas in the East for employment with our fleet. This is a reduction of 2 flotillas on the force that has been assumed in previous calculation to be required in a Far Eastern war, a reduction that is justified by the definition of the new standard of naval strength wherein it is stated that "the fleet in the Far East should be fully adequate to act on the defensive and to act as a strong deterrent, &c." Of these flotillas, 2 should be of the new "Tribal" type which is being developed for the purpose of strengthening the gun power of the flotillas, and it has been calculated is a sufficient set-off against the 23 destroyers of the ''Fubuki'' type in the Japanese fleet.

43. In addition, 2 flotillas must be allowed for A/S duties or escort work in the Indian Ocean and Malacca Straits for the protection of important convoys of fleet oilers and supply ships which might be the object of Japanese submarine attack.

44. Our minimum destroyer requirements for the Eastern area are, therefore, as follows:—

​

Home Waters.
45. The Home Fleet is expected to comprise 10 battleships for employment with which we need 5 modern flotillas. For the present it is assumed that these flotillas will all be of the ordinary type, but since Germany is, at present, building destroyers of 1,625 tons armed with 5-inch guns, the situation will require watching so as to ensure that the gun power of the fleet flotillas does not become greatly inferior to that of a possible German destroyer force that may operate with their battle fleet.

46. For patrol services in the North Sea and Dover Straits we require a force of 4flotillas of which at least 2flotillas should be of the "Tribal" or "J" type, so as to give superiority over the destroyers now being built by Germany. If Germany continues the construction of large destroyers it might be necessary that all 4 flotillas should be of the "Tribal" type, since the services on which they would be employed would be principally of the type of fighting that occurred in the Dover patrol and Harwich forces during the European War. For other local defence, escort and patrol work in the channel and the approaches to the British Isles, and for the protection of transports and important fleet communications, another 3flotillas of over-age destroyers would be required.

47. The calculation of the A/S forces required for the protection of our trade cannot be based solely on the size of the enemy submarine force that may attack it. It was demonstrated during the last war that, if unrestricted attack is embarked upon, the most effective protection is to use these forces as escorts in a general convoy system and thus make the submarine come to the A/S vessel.

If the severity of the attack is sufficient to require the organisation of a general convoy system, the minimum number of escort vessels required is dependent directly on the number of convoys to be escorted. It is estimated that over 100 A/S escort vessels are required for a complete convoy system in Home waters, the Atlantic and Mediterranean.

48. Although Germany has adhered to the rules for submarine warfare contained in Part IV of the London Naval Treaty, 1930, we cannot rely for our security on her observance of these rules, and, further, in conditions to-day air attack on our shipping in home waters is a possibility. The Admiralty are consequently increasing their strength in escorting vessels by converting 4 flotillas of old destroyers for special A/S and A/A duties, but though these vessels will be retained, they cannot be counted as ''destroyers'' when assessing our strength in this type of vessel.

49. Our minimum requirements in Home waters, therefore, are:―

​

50. Our total requirements for Far East and Home waters therefore become:―

​

That is, 22 flotillas in all, of which 16 flotillas should be under-age and 6 flotillas may be over-age.

To maintain this strength involves an ultimate steady replacement programme of 1 flotilla a year.

This comes from the same source as the previous messages.

 

[NOMISYRRUC]

This is how the requirement for 82 submarines was calculated and is from the same source as the previous posts.

Submarine Strength.
51. In all international discussions in the past 16 years we have stated our willingness to abolish submarines and failing abolition our policy has been to keep all submarine fleets down to the minimum, both in numbers and sizes of ships. In advocating this policy the Admiralty have had in mind that, while there are certain duties for which submarines are of great value to us and which they alone can perform, on the wider aspects the existence of the submarine is to our disadvantage, our interest being the supremacy of the surface ship.

All proposals for numbers and tonnages of submarines put forward by the Admiralty in recent years have accordingly been based on the above considerations rather than on our strategical needs for this weapon if it is retained.

52. It is now certain that the submarine will not be abolished nor can we obtain any limit to its numbers. The only thing we can obtain is an assurance (so far as the signed word can give such assurance) that submarines will not again be used in the inhuman manner in which they were used in the great war.

53. It is consequently necessary for the first time for many years to consider our submarine requirements on a strategical basis. The submarine strength required by a country is almost entirely independent of the submarine strength of other countries (i.e., it is absolute, not relative), because these vessels in general act independently and not even in company with one another, and also because the submarine is not the answer to the submarine.

54. Our submarine strength resulting from the policy outlined above was 50 vessels on the conclusion of the Treaty on the 31st December, 1936, and the Admiralty have always realised that this number did not meet our strategical requirement if the submarine was to be retained as a weapon of war-this was the case either on the old or the new standard of strength. The number of submarines required to meet our strategical requirements is examined below.

55. In carrying out this examination the numbers required have been kept down to the minimum because of the reactions of our strength on that of Germany. Though it is very unlikely that Germany would embark on unrestricted submarine warfare again, it is desirable to limit her number as far as possible, especially as she may in certain circumstances have up to 100 per cent of our strength in this category. The estimate which follows is consequently confined to essentials and results in a smaller total than would be desirable on purely strategic grounds.

56. In the Far East with our fleet on the defensive the submarine would be of great value in hampering the freedom of action of the Japanese fleet and obtaining information off the Japanese coasts which could not otherwise be obtained.

57. It is also of great importance that submarines should be stationed in the Far East in time of peace, because they are the only vessels which could operate against the Japanese forces with much prospect of success in the period before the battlefleet reached the East and thereby they could contribute greatly to the security of our bases in that part of the world. (To-day our submarine strength in the East is large in comparison to our surface strength, and it would be larger still had more submarines been available in recent years.)

58. The following submarines are considered the minimum to carry out the role required in the Far East:—

​

59. In Home waters in a war with Germany approximately 7 submarines will be required on continuous patrol in the North Sea, to maintain which a total of approximately 30 submarines is required. Included in this number is a small allowance for special operations as well as routine patrol work.

60. We also require a few submarines of a special type for work with the fleet, and a unit of minelaying submarines is also necessary.

61. In addition, it is essential in war as in peace to keep a number of submarines for training work because of the specialised nature of the training involved—this training is not only in the use of the submarine itself, but in the training of anti-submarine forces which can only be carried out against actual submarines.

62. Our total minimum requirements in Home waters are accordingly:—

​

Of the above, 7 training submarines can be over-age.

63. In addition to the above forces in the Far East and Home waters, it is considered necessary for a small force of submarines to be based in the Mediterranean to meet probable operations in that sea (as was the case in the Great War). These submarines would also form a strategic reserve to proceed to the Far East or Home waters if required. The number of submarines required for this duty is 6.

64. Our total minimum submarine requirements are consequently: —

*******************************************************************************************************************************​

Both London Naval Treaties said that a submarine became over-age 13 years after its date of completion. Therefore, an average building rate of 6 boats a year was required to maintain a fleet of 75 under-age submarines.

That was the end of the appendix to the enclosure. It didn't say how the requirement for 226 minor war vessels was calculated. That was because the enclosure didn't mention the 226 minor war vessels. They came from a different source.

 

[NOMISYRRUC]

The RN had a total of 57 submarines on 03.09.39 as follows:

9 H class completed 1918-20.​

3 L class completed 1924-26.​

3 O class (first and second groups) completed 1927.​

6 O class (third group) completed 1929-30.​

5 P class completed 1930-31.​

A sixth boat of this class (Poseidon completed in 1930) was lost in 1931.​

4 R class completed 1930-31.​

12 S class completed 1932-38.​

3 T class completed 1938-39.​

3 U class completed 1938.​

3 Thames class completed 1932-35.​

6 Porpoise class minelaying boats completed 1933-39.​

That was 25 boats short of the requirement for 82 submarines and 12 were over-age instead of 7.

Another 23 submarines should have been building or planned. However, the number of boats in the 1938-39 Navy Estimates was cut from 7 to 3 and the number of boats in the 1939-40 Estimates was cut from 7 to 4. This reduced the number of submarines building or planned to 16.

• Thus 12 T class boats were under construction on 03.09.39 (instead of 16) and IOTL they were completed between 16.09.39 and 14.01.41.
• And 4 T class boats were planned. They were in the 1939-40 Estimates and hadn’t been ordered (let alone begun) when war was declared.
• 24 submarines were ordered in the War Emergency Programme and 7 of them were T class boats. The first 4 of those were laid down from November 1939 to March 1940 and were completed from May to December 1941.

Therefore, the RN would have had 73 submarines on 07.12.41 ITTL, which was 9 short of the required number and 15 would have been over-age instead of 7.

I don’t know how many submarines the Admiralty wanted built under the 1940-41 and 1941-42 Navy Estimates (@EwenS might) but none of them would have been completed before the end of 1941.

 

[NOMISYRRUC]

Following-on from Message 92, this table shows which Navy Estimates the 45 under-age submarines and the 12 boats that were under construction at 03.09.39 were built under.

​

 

[NOMISYRRUC]

Part of the Opening Message.

Aircraft Carriers

• 1 Argus-class: still extant as a training platform.
• 1 Hermes-class: refitted in 1940-41 with new AA armament of 2x2 4in DP mounts and 2x8 pom-poms, still working up post-refit.
• 1 Eagle-class: on China Station at outbreak of war, no recent refits.
• 3 Courageous/Furious-class: not yet retired but planned to do so once Implacables complete, no recent refits
• 1 Ark Royal-class: no recent refits, maybe 2x4 or 2x8 extra pom-poms at most
• 4 Illustrious-class: all completed by 1940
• 0 + 3 Implacable-class: Indefatigable and Implacable will complete in late 1942, Irresistible ordered under 1940 Programme with slight modifications and only just laid down, scheduled to complete in 1945 [note this ship was briefly ordered OTL but soon swapped for first Audacious-class, in the absence of war experience its seems likely the bigger Audacious would not be ordered in 1940 but welcome to hear arguments for it].
• 1 Unicorn-class: completed just before outbreak of war in November 1941.

I'm doing the following from memory, so it won't be 100% accurate, but it will be close enough and @EwenS will correct any major lapses of memory.

• Argus paid off into reserve in September 1932 and was recommissioned on 11.08.38 as a depot ship for Queen Bee target drones. Her Wikipedia entry says she was officially called a Target Aeroplane Carrier and an auxiliary rather than a warship. Jane's 1939 has her in the RN's auxiliaries section, rather than its aircraft carrier section. However, her Wikipedia entry says she was also used as a deck landing training ship and on 03.09.39 was carrying out this duty in the Gulf of Lion.
• I completely disagree about Courageous, Furious & Glorious.
  • The plan from circa the Abyssinian Crisis was to have 14 aircraft carriers by the middle 1940s, which would consist of Ark Royal, Courageous, Furious, Glorious and 10 armoured carriers of the 23,000-ton type.
  • I think Furious didn't become over-age until 1925, followed by Courageous in 1948 and Glorious in 1950 because it was calculated as 20 years from the completion of their conversions to flush-deck aircraft carriers, rather than when they were completed as light battle cruisers.
  • Furious was in service as the deck landing training ship when war broke out IOTL and I think she would have been the training carrier when war broke out ITTL too.
• I agree about Ark Royal, Eagle, Hermes and the completion dates for the Illustrious class.
• Therefore, the RN would have had 11 aircraft carriers at the end of 1941 ITTL, instead of the 7 that it had in September 1939 in both timelines.
  • However, the improvement would have been greater than that because one ship had been converted into an auxiliary and another was a non-operational training ship on both dates.
  • Therefore, the number of operational aircraft carriers had increased from 5 in September 1939 to 9 at the end of 1941.
  • Furthermore, if the expansion of the FAA was proceeding as planned there's be approaching 360 first-line carrier aircraft in 30 squadrons aboard them instead of the 162 first-line aircraft in 15 squadrons that existed on 03.09.39.
• Implacable was laid down in March 1939 and I think she'd be completed around March 1942.
• Indefatigable was laid down in November 1939 and I agree that she'd be completed in late 1942.
• You may be pessimistic about Unicorn too. She was laid down at the end of June 1939 and may have been completed in the late summer of 1941 rather than November 1941.
• They're the likely completion dates for Implacable, Indefatigable and Unicorn in normal peacetime conditions. However, if the TTL Pacific War had been brewing for some time the Admiralty would have been doing all it could to get these ships into service sooner.
• The Second London Naval Treaty would have remained in force until December 1941 ITTL so the 1940 Carrier couldn't be built to the OTL Audacious design. It had to be a repeat of Implacable or a new design with a standard displacement not exceeding 23,000 tons. For that matter the American Essex class would have to displace 23,000 tons rather than their OTL standard displacement of 27,000 too. That is, unless, the American, British and French governments agreed to increase the permitted maximum displacement of an aircraft carrier. There is an OTL precedent for this, because the Treaty was modified to allow capital ships to displace 45,000 tons instead of 35,000 tons in June 1938.
• Irresistible (1940-41 Estimates) would have been laid down in 1940 for completion in 1943 and a fourth Implacable class (1941-42 Estimates) would have been laid down in 1941 for completion in 1944. That would have increased the number of aircraft carriers to the 14 that were required. However, they'd have been Ark Royal, Courageous, Glorious, Furious and 8 ships of the 23,000 ton type plus Eagle and Hermes. Therefore, an aircraft carrier would have been planned for the 1942-43 Estimates to replace Eagle in 1945 and another ship would have been planned for the 1943-44 Estimates to replace Hermes in 1946.
• Except, the original plan was to build the ten 23,000 ton aircraft carriers at the rate of 2 per year.
  • Therefore:
    • Illustrious & Victorious were built under the 1936-37 Navy Estimates. (Due to the Second London Naval Treaty they couldn't be laid down until 1937).
      • And.
    • Formidable & Indomitable were build under the1937-38 Estimates.
  • The Rearmament Programme of 1936 created demand pull inflation and a balance of payments deficit, because the run down British armaments industry couldn't cope with the sudden increase in demand. (E.g. the armour shortage.) As a result the building programmes for the 1938-39 and 1939-40 Estimates were "Rationed" and the number of ships built under them was less than planned.
    • This was why the number of submarines built under the estimates for those years was cut from 14 to 7.
    • It is also why one aircraft carrier (Implacable) was built under the 1938-39 Estimates, instead of 2.
    • And why one aircraft carrier (Indefatigable) was built under the 1939-40 Estimates, instead of 2.
  • The British armaments industry expanded somewhat between 1936 and 1940, so they might go back to ordering 2 aircraft carriers a year from the 1940-41 Estimates onwards.
  • So a pair of ships might have been laid down in 1940 for completion in 1943 and another pair laid down in 1941 for completion in 1944.
  • In which case the target of 14 aircraft carriers would have been reached in 1943 instead of 1944 with Eagle & Hermes being replaced in 1944 instead of 1945 and 1946 respectively.

 

[NOMISYRRUC]

Part of the Opening Message.

To make a change from the usual what-ifs I wondered what the impact would be to the Royal Navy if the Far Eastern War had broken out as historically in December 1941, but there had been no European War?

It can't break out exactly as historically. No European War, means no Fall of France. Which in turn, means no Japanese occupation of French Indo-China and IIRC that was the immediate cause of the Pacific War IOTL. At the very least, there'll be no Japanese torpedo-bombers there to attack the TTL version of Force Z.

Also if there's no European War and no Fall of France there's a considerable knock-on effect on US naval shipbuilding between September 1939 and December 1941. No Two Ocean Navy Act for a start.

I've also mentioned that the Second London Naval Treaty would still be in force. Therefore, as well as no Essex class as we know it, there'd be no Baltimore and Cleveland classes as we know them either. That is, unless the Americans, British & French suspected that the Japanese were building aircraft carriers & cruisers that greatly exceeded the Treaty's displacement limits and agreed to amend the Treaty accordingly, as they did for capital ships in 1938.

 

[NOMISYRRUC]

Capital Ships

• 5 QE-class: Queen Elizabeth, Valiant and Warspite rebuilt 1934-40; Malaya and Barham less extensively refitted
• 3 (2) R-class: not much done any of these ships since 1939; Royal Oak of the best standard, Royal Sovereign in 1939-40 received new bulges and 30° elevation for her 15in turrets. Resolution and Ramillies paid off by 1942 in reserve to free manpower for KGVs
• 2 Renown-class: Renown completed reconstruction in 1939; Repulse began her reconstruction in 1941 and not due to complete until early 1943
• 1 Hood-class: began her reconstruction in 1940 with revised deck armour, new 4.5in secondaries and catapult and hangars, due for completion in late 1942 and delayed due to structural complications
• 2 Nelson-class: Nelson began reconstruction in 1940 with additional armour forward and at base of belt and new 5.25in secondaries, catapult and hangars aft, due for completion in mid-1942; Rodney began her reconstruction in 1941 and won’t complete until 1943
• 3 + 2 KGV-class: KGV, PoW and DoY completed (latter 2 still working up); Anson and Howe will complete during 1942.
• 0 + 4 Lion-class: Lion and Temeraire were launched during 1941 and will complete in 1943; Conqueror and Thunderer laid down in 1941 and will complete in 1944.
• 0 + 1 (5?) Vanguard-class: approved early 1941 and laid down in October, to complete in 1944-45. Discussions ongoing as to ordering another 4 ships using turrets from the R’s as they decommission.

I more or less agree.

The most important less is that at least 6 Lion class would be under construction instead of 4. Conqueror & Thunderer were in the 1939-40 Navy Estimates and would have been laid down in 1940. IIRC a third pair of ships was projected for the 1940-41 Estimates and would have been laid down in 1941 ITTL. A fourth pair of Lions would have been in the 1941-42 Estimates to be laid down in 1942.

 

[DWG]

IOTL the first flight dates of the next generation of naval aircraft were;

...​

29.06.41 Fairey Barracuda.​

...​

Wiki has Barracuda Mk 1 first flight as 7-Dec-1940, I'm away from my bookshelves so can't check against more reliable references, but might the 1941 date be the MkII.

All I can say with some confidence is that the Barracuda probably goes into service with the Exe rather than the Merlin.

Agreed, and potentially somewhat earlier, though it is dependent on when the Exe is ready. OTOH the Exe-powered Battle testbed is supposed to have been reliable, so the Exe seems to have been reasonably mature when abandoned.

 

[NOMISYRRUC]

Part or the Opening Message.

Cruisers

• 5 Ceres-class: only Coventry, Curlew and Curacoa have AA cruiser refits of these only latter has twin 4in mounts
• 5 Carlisle-class: all have received AA cruiser refits by end of 1941
• 8 D-class: still extant overseas, some on China station at outbreak of war, no AA conversions begun but plans have been made for 4x2 4.5in UD mounts and 1x4 pom-pom.
• 1 (2) Hawkins-class: Effingham has 9x1 6in guns, but Hawkins and Frobisher did not receive them and in reserve
• 2 E-class: no recent refits
• 11 County-class: London completed reconstruction in early 1941, Shropshire begun conversion during 1941 and will not complete until 1943. [The structural effects of the London’s additional weight will be less drastically proved in the absence of war service, would more reconstructions be worth it?]
• 2 York/Exeter-classes: no recent refits
• 9 Leander/Arethusa-classes: no recent refits
• 8 Southampton-class: all completed by 1939
• 2 Edinburgh-class: completed 1939
• 10 Dido-class: the last just completed before the outbreak of war [note in this scenario the 6 1939 War Programme ships were never ordered]
• 11 Fiji-class: last 3 completing within next six months
• 0 + 3 Minotaur-class: 3 ships under 1941 Programme for completion in 1943-44
• 6 Abdiel-class: Apollo and Ariadne under 1941 Programme just laid down for completion in 194

The C and D classes

By accident or design, you haven't included the 3 Caledon class. IOTL 6 C class ships (Cairo, Calcutta, Carlisle, Coventry, Curacoa and Curlew) were converted 1935-40 and 2 more (Caledon & Colombo) were converted 1942-43. I think all 13 C class light cruisers would have been converted to AA ships by the end of 1941 ITTL. Conversion of some D class cruisers to AA ships may have been in progress at the end of 1941.

The Hawkins and E classes

You've not included Vindictive either. I think she'd be rearmed a la Effingham 1939-40 instead of being converted to a repair ship 1939-40. Effingham also had four single 4in AA guns fitted when she was rearmed with nine 6in guns. They single 4in guns were replaced by twin 4in AA guns in a refit in 1939-40. She also received two quadruple 2pdr, two quadruple 0.5in and HACS over the course of these refits. I think that Hawkins and Frobisher would have at least had their AA armaments modernised to this standard by the end of 1941 too. I also think that the 2 E class cruisers would have had their AA armaments modernised to the same standard as Effingham as well.

The Number of Counties, Leanders and Arethusas is wrong.

You've said 11 County class instead of 13 and 9 Leander/Arethusa class instead of 12. Are the missing ships Australia, Canberra, Hobart, Perth and Sydney? You haven't mentioned Adelaide either. I think she'd still be around at the end of 1941.

The Dido class

I agree that only 10 Dido class would have been ordered and that they would have been completed by the end of 1941. They were: built under the 1936-37 & 1937-38 Estimates; laid down from August 1937 to April 1939; launched from February 1939 to September 1940, and; completed from May 1940 to June 1942. The average building time was 38 months from laying down to completion. IOTL 8 out of 10 were completed before the end of 1941 anyway and the other 2 were completed May to June 1942. However, I think that ITTL the building time would be closer to 30 months (the average for the 22 Leander to Edinburgh class cruisers) in which case the 10 ships would have been completed between February 1940 and October 1941.

The Fiji class build under the 1937-38 to 1939-40 Estimates

4 Fiji class were to have been built under the 1939-40 Estimates, but only 2 (Bermuda and Newfoundland) had been ordered by 03.09.39. IOTL their place was taken by 2 of the 6 Dido class build under the War Emergency Programme. There wasn't a war emergency until December 1941 ITTL so the third and fourth Fijis in the 1939-40 Estimates would have been ordered in the autumn of 1939 and laid down in the winter of 1939-40 for a total of 13 ships.

IOTL

• 5 Fiji class were built under the 1937-38 Estimates.
  • They were laid down from February to June 1938, launched from May 1939 to March 1940 and completed from May 1940 to October 1941.
  • The average building time was 32 months from laying down to completion.
  • Fiji was the fastest at 25 months and Trinidad was the slowest at 42 months. They were also the first and last ships of this group to be completed.
  • The other 3 ships in this group were built in 27 to 33 months.
• 4 Fiji class were built under the 1938-39 Estimates.
  • They were laid down from April to July 1939, launched from November 1940 to July 1942 and completed from February 1942 to July 1943.
  • The average building time was 40 months from laying down to completion.
  • Gambia was the fastest at 31 months and Ceylon was the slowest was Ceylon at 51 months. They were also the first and last ships of this group to be completed.
  • The other two were built in 38 months each.
• 2 Fiji class were built under the 1939-40 Estimates.
  • They were laid down in November 1939, launched in September & December 1941 and completed in August 1942 & January 1943 respectively.
  • The average building time was 36 months from laying down to completion.
  • Bermuda was built in 33 months and Newfoundland took 38 months to build.
• 6 Dido class were built under the War Emergency Programme.
  • They were laid down from November 1939 to March 1940, launched from September 1941 to September 1942 and completed from August 1942 to January 1944.
  • The average building time was 44 months from laying down to completion.
  • The fastest was Argonaut was the fastest at 33 months and Diadem was the slowest at 50. They were also the first and last ships of this group to be completed.
  • The other 4 took between 42 and 49 months to build.

ITTL

• 5 Fiji class were built under the 1937-38 Estimates.
  • Trinidad would have been built in around 30 months (like the other 4 ships in her group) advancing her completion from October 1941 IOTL to October 1940 ITTL.
  • However, as all 5 ships were completed by the end of 1941 anyway, this doesn't alter the number of cruisers available at the end of 1941 ITTL.
• 4 Fiji class were built under the 1938-39 Estimates.
  • The average building time for the ships in this group would have been reduced from 39 months to 30 months.
  • This may mean that:
    • Ceylon and Jamaica were completed in October 1941 instead of July 1943 and June 1942
      • While.
    • Gambia and Uganda were completed in January 1942 instead of February 1942 and January 1943.
  • So 2 would have been entered service shortly before the start of the TTL Pacific War and the other 2 would have entered service not long after it began.
• 4 Fiji class were build under the 1939-40 Estimates.
  • Bermuda and Newfoundland would have been laid down in November 1939 as IOTL.
  • The third ship would have been laid down in November 1939 in place of the Dido class Argonaut.
  • The fourth ship would have been laid down in November 1939 too and taken the place of one of the three other Didos laid down in November 1939 IOTL. For the sake of argument I'm saying that it was built instead of Diadem.
  • My guess is that the building times for all 4 ships would be an average of 30 months.
    • Bermuda was still built in 33 months and was completed in August 1942.
    • Newfoundland was built in 27 months instead of 38 bringing her completion forward from January 1943 to February 1942.
    • The ship built instead of Argonaut being built in 33 months like Argonaut and was completed in August 1942 like Argonaut.
    • The ship built instead of Diadem was built in 27 months, which brought her completion forward from January 1942 to February 1942.
• So the short answer is that 7 out of 13 Fiji class built under the 1937-38 to 1939-40 Estimates ITTL were completed before the end of 1941, with 4 more nearing completion and the other 2 due to be completed during the summer of 1942.

Cruisers laid down 1940-41

At least 5 Fiji class would have been laid down in 1940 under the 1940-41 Estimates and at least 4 more would have been laid down in 1941 under the 1941-42 Estimates. The 1940 ships were due to be completed 1942-43 and the 1941 ships in 1943-44 when the RN, RAN & NZ Division would have had a total of 97 cruisers of which 28 were over-age*. This was against a requirement for 100 of which 15 could be over-age so while the actual number was only 3 short of the target, the ratio of under-age to over-age ships was 69:28 instead of 85:15.

This is because a building rate of 4 cruisers a year (plus a 5th ship every leap year) was required to maintain a force of 85 under-age cruisers.

At that rate the target of 100 cruisers would be reached in 1945 when the third of the 4 cruisers built under the 1942-43 Estimates and laid down in 1942 was completed. Then the number of over-age ships could be reduced to 14 in 1948 when the last of the 4 ships ordered in the 1945-46 Estimates was completed. But 1948 is when the first 7 of the County class begin to become over-age so the ratio of under-age to over-age ships would jump from 86:14 to 79:21.

Therefore, the Admiralty probably wanted more cruisers laid down in 1940 and 1941 to reach the target of 100 cruisers ASAP and get the ratio of under-age to over-age cruisers down to 85:15 ASAP. For example (AFAIK) the Admiralty wanted to have 7 cruisers built under the 1939-40 Estimates but it was reduced to 4 as part of the "Rationing" of the 1938-39 and 1939-40 Estimates.

Conclusion

In both timelines the RN, RAN & NZ Division had a total of 65 cruisers on 03.09.39 of which 24* were over-age and another 23 were building, on order or planned. That was against a requirement for 100 cruisers of which 15 could be over-age. So it was 35 ships short of the target and the ratio of under-age to over-age ships was 31:24 instead of 85:15.

ITTL the RN, RAN & NZ Division had a total of 82 cruisers at the end of 1941 of which 26 were over-age* and at least 16 were building, on order or planned. This was still 18 ships short of the target of 100 cruisers and the ratio of under-age to over-age ships was 56:26 instead of 85:15.

Note

* The 24 over-age ships in 1939 were Adelaide, the 13 C class, 8 D class, Hawkins and Vindictive. Frobisher became over-age in 1940 and Effingham in 1941 for a total of 26 over-age cruisers at the end of 1941. The 2 E class cruisers didn't become over-age until 1942, which is why there'd be 28 over-age cruisers in 1944.

 

[NOMISYRRUC]

Wiki has Barracuda Mk 1 first flight as 7-Dec-1940, I'm away from my bookshelves so can't check against more reliable references, but might the 1941 date be the Mk II.

You're 100% correct. I'm 100% wrong.

My source was Page 165 of my Putnams "British Naval Aircraft since 1912" which I didn't read properly, because it clearly says in the first paragraph that P1767 (the first prototype) made its maiden flight on 07.12.40. In the next paragraph it clearly states that 29.06.41 was the first flight of P1770 (the second prototype). So I misread the first flight of the second prototype as the first flight of the first prototype. FWIW I'm extremely angry with myself for making such a stupid mistake.

While I've got the book open.

• 18.05.42 first flight of the production Barracuda Mk I (P9642) with the 1,260hp Merlin 30 engine.
• 18.05.41 date of the prototype Barracuda's first deck landing.
• 17.08.42 first flight of the prototype Barracuda Mk II (P1767 again) with the 1,640hp Merlin 32 engine.
• The prototype for the Barracuda Mk III was DP855 (a converted Mk II) which first flew in 1943.
• It doesn't say when the first production Barracuda III flew, but it does say that a grand total of 2,572 Barracudas of Mks I, II & III were built: 1,162 by Fairey at Heaton Chapel, 700 by Blackburn, 692 by Boulton Paul and 18 by Westland.
• 10.01.43 No 827 Squadron reformed at Stretton, Cheshire with 12 Barracuda Mk IIs.
• No. 810 became the second first-line squadron in February 1943 and there were 12 first-line Barracuda squadrons in January 1944.
• 16.11.44 first flight of the Barracuda Mk V prototype (P9976 a rebuilt Mk II).
• 22.11.45 first flight of RK530 the first true-built Barracuda V, but this mark was mostly used for training duties and never entered first-line squadron service.

 

[Hood]

I completely disagree about Courageous, Furious & Glorious.

Fair enough if plans foresaw keeping them (and they would still exist in this AH in 1942 in some form). They would increasingly be second-line ships I think unless some serious refit work was done to them, but that's unlikely before the 1942 departure date.

The most important less is that at least 6 Lion class would be under construction instead of 4. Conqueror & Thunderer were in the 1939-40 Navy Estimates and would have been laid down in 1940. IIRC a third pair of ships was projected for the 1940-41 Estimates and would have been laid down in 1941 ITTL. A fourth pair of Lions would have been in the 1941-42 Estimates to be laid down in 1942.

Sounds better than Vanguards - though the capacity to manufacture armour plate and 16in guns would be a factor I would think in keeping this programme rolling to schedule.

By accident or design, you haven't included the 3 Caledon class.

By design, better to dump these and use the manpower on newer ships.

Conversion of some D class cruisers to AA ships may have been in progress at the end of 1941.

I would be sceptical of this in peacetime given the needs of the fleet, but as I said the plans would be more or less ready to go by early 1942.

You've not included Vindictive either. I think she'd be rearmed a la Effingham 1939-40 instead of being converted to a repair ship 1939-40.

Vindictive is a bit of an oddity, probably of more use as a repair ship to be honest.

Are the missing ships Australia, Canberra, Hobart, Perth and Sydney? You haven't mentioned Adelaide either.

Yes, this is an RN list so excludes the RAN.

4 Fiji class were to have been built under the 1939-40 Estimates, but only 2 (Bermuda and Newfoundland) had been ordered by 03.09.39. IOTL their place was taken by 2 of the 6 Dido class build under the War Emergency Programme. There wasn't a war emergency until December 1941 ITTL so the third and fourth Fijis in the 1939-40 Estimates would have been ordered in the autumn of 1939 and laid down in the winter of 1939-40 for a total of 13 ships.

I concede it would be possible to built 13 Fijis rather than 11, but I generally dislike the disruption these vessels caused when they were batch built and rather hurried under wartime conditions, so I've tried to iron that out a little.

Generally I err on the side of caution when estimating build times.

 

[EwenS]

Looking back through recent posts on this thread, there is a lot to unpack. Some of this I have noted before either here or on other threads.

General
The "New Standard Fleet" (NSF for shorhand here) plan drawn up in Feb 1936 was never formally adopted by the Admiralty. It did however become something of a guide but should be considered no more than that, even though actual orders followed it reasonably closely. But behind the scenes there was a lot of discussion about what should be ordered & when. So plans kept changing.

And of course WW2 intervened to throw everything off. So separating the planned Programmes from the changes proposed in the last few months of peace adds to the difficulty.

Battleships.
NSF proposed 2 per year from the !936 Progamme (1936/37 in NOMISYRRUC speak - sorry but I find that usage confusing), to the 1942 Programme, with 3 in 1937 & !939 plus 1 in each of !943 & 1944. Total of 18 new ships completing through to about 1950. The limiting factors were gun, armour & turret production.

1938 Programme included the first two Lions. Contracted build time from order to completion was 42 months. Ordered in Feb 1939, in Sept 1939 the RN was expecting them in service in Aug 1942. John Brown tendered on this basis and lost out. See "The Battleship Builders."

1939 Programme included the second pair. This time the contracted build time from John Brown for Conqueror was 52 months for reasons unexplained. Again see "The Battleship Builders". Conqueror was ordered Aug 1939 which would suggest completion at the end of 1943. Thunderer was scheduled to be ordered from Fairfield in Nov 1939 which would suggest completion in March 1944.

Given the projected longer build time for the second pair must raise doubts about the build time for the first pair. On top of that the WW2 experience at Fairfield was that pre-war and 1939 War Programme orders were overloading the yard, which throws the above completion dates for Thunderer into some doubt. She would have to have awaited the launch of Howe before beng laid down, if my research is correct. That happened in April 1940.

The 1940 Programme was discussed from July 1939. Projected build time being discussed was 42 months assuming armour, guns & turrets could be delivered timeously. They could be ordered in July / Aug 1940 at Swan Hunter & Harland & Wolff. That would suggest completion Jan / Feb 1944. But again was 42 months realistic?

Also under discussion at this time was what became Vanguard. Estimated build time an optimistic 36 months, again if no delays with armour, guns & turrets. VA (Tyne) was the yard initially earmarked. But money needed spent at the H&W gun factory on the Clyde to dig out the gun pits to rebuild the turrets from Glorious & Courageous.

Carriers
Difficult to know where to start.

Firstly, the wording in the Treaties about their replacement refers to "from completion" and not "completion of reconstruction as carriers". From the 1936 London Treaty.

Article I

Vessels of the following categories and sub-categories shall be deemed to be "over-age" when the undermentioned number of years have elapsed since completion:​

(b) Aircraft carriers 20 years​

This followed the principle laid down in WNR 1922 Part 3, Section 1(a). And also Article X AIUI with my emphasis

Article X​

Vessels which were laid down before the date of the coming into force of the present Treaty, the standard displacement or armament of which exceeds the limitations or restrictions prescribed in this Part of the present Treaty for their category or sub-category, or vessels which before that date were converted to target use exclusively or retained exclusively for experimental or training purposes under the provisions of previous treaties, shall retain the category or designation which applied to them before the said date.​

So Argus, Eagle, Hermes & Furious retained their "experimental" status conferred by the Article VIII WNT 1922 and could be replaced anytime regardless of age. So C & G could be replaced from 1936 given their completion in Oct 1916. (see the comment below in Moore about replacing them with new ships in the 1942, 1943 & 1944 Programmes i.e. with completion dates probably somewhere between 1945 & 1948). While this pair had been rebuilt in the 1920s, they still retained their original machinery.

Programmed replacement
1936 Illustrious & Victorious
1937 Formidable & Indomitable
1938 Implacable
1939 Indefatigable
1940 Irresistible (possibility of a second was briefly considered as part of a max build programme but probaly beyond industry capability with all the other orders)
1941 AN Other.

There is a paragraph in Moore "Building For Victory" that is particularly relevant here, dating to discussions about the 1939 Programme that took place in Dec 1938/Jan 1939:-

"The aircraft carrier programme as already agreed was to build one carrier in the years 1939, 1940 and 1941. Anothet idea was to build one carrier in each of the years 1939 to 1944 inclusive. This would allow for the replacement of Glorious, Courageous and Furious, but the First Sea Lord did not give his support. He commented that 'this programme cannot be decided so far in advance'. In the event one aircraft carrier, the Indefatigable, was to be ordered in June 1939. This ship was regarded as a replacement for one of the older carriers in the fleet."

Now we need to turn to ADM 1/10133 A Minute by the Director of Naval Air Division dated 11 May 1939. Having consulted with DNAD & Dof P there was an Appendix showing a forecast allocation of carriers and other aircraft carrying ships Apprndix in 1942 (exact date not specified) in the event of peace, war in Europe alone & war in the Far East alone. It is the first and last of these that is of interest with aircraft numbers in brackets.

Peace
Formidable (33), Illustrious (33) & Indomitable (45) in Home Waters. Courageous (24) training carrier of in Reserve. Glorious (24), Furious (0) & Hermes (12) in Reserve. Implacable (48) & Indefatigable (48) at Alexandria / Malta. Victorious (33) at Trincomalee or Kingston, Jamaica. Ark Royal (60) at Singapore.

Far East War
Formidable, Illustrious & Victorious in Home waters with Furious (0) as the training carrier. Courageous (24) at Trincomalee. Ark Royal, Indomitable, Implacable, Indefatigable and Glorious(24) at Singapore. Hermes at Kingston, Jamaica.

This raises a number of points of interest.

1. No mention of Argus & Eagle.
Argus is explained by her conversion to a Queen Bee auxiliary. Incidentally she was in Home Waters on 3 Sept 1939 and may even have been in Reserve. At the same time Furious was the Training Carrier operating out of Rosyth. The loss of Courageous on 17 Sept 1939 necessitated changes amongst the carriers. Furious was brought forward as an operational carrier in Oct 1939 taking one Swordfish squadron from Ark Royal (818) and forming a second (816) from training units that had been using her deck. Argus then assumed the deck landing training role. She embarked 767 squadron on 13 Nov 1939 and sailed for the Med where the squadron split its time at Hyeres or aboard as circumstances dictated. The objective of this move was to seek better weather from what turned out to be a severe winter. She returned to Britain in June 1940.

The absence of Eagle seems to tie in with with Moore's comment about Indefatigable replacing one of the old ships. Without the benefit of Article X LNT 1936 she could not have been replaced until 1944. Also worth noting that by the time she was refitted at the end of 1941 she was in need of reboilering, suggesting her machinery was worn out.

2. The reduced aircraft complements on C & G and their locations at Trincomalee & SIngapore suggests that they, along with Hermes were filling a "trade protection" role rather than that of a fleet carrier. Even allowing for an increase in aircraft size, a reduction from 48 Swordfish / Sea Gladiators in 1939 to just 24 unidentified types in 1942 that seems the only logical explanation.

3. In Sept 1939 the expected completion dates for Implacable & Indefatigable were Oct 1941 & June 1942 respectively, being 32 months from being laid down to completion. These completion dates seem optimistic compared to the Illustrious class but there are a number of factors to take account of like delays in armour deliveries for the latter. These ships saw a lot of modifications to the design during 1941 & 1942 that caused delays. Without those, and with the ability to work longer peacetime hours with no blackouts ets, maybe 32 months would have been achievable. But on the other hand Fairfield!

The larger forward lift for Indomitable seems to only have been considered in Sept 1940 (DNC Goodall's diaries), which is about the time that the FAA acquisition of Sea Hurricanes gained momentum. So she and the Implacables may not turn out entirely as historical.

Cruisers
C & D classes
The number of C class AA conversions changed over time. Coventry & Curlew had been converted during the Abyssinian Crisis with single 4" guns. Initial plans saw all 13 being converted. Then the 3 Caledon sub-group, without a superfiring B gun, were eliminated around April 1937 due to their different layout that required a separate design (notwithstanding that, Caledon was converted in 1942/43). Due to age considerations the final total was cut back to just 6 more ships as of Feb 1939. The outbreak of WW2 prevanted the last pair earmarked, Capetown & Colombo, from beginning conversion.

All 8 D class cruisers were to be converted to AA ships with 4 twin 4.5" Mk.III mounts + light AA. Orders for the guns were placed in 1938. Work on these was to begin in Jan 1940 on 3 ships with completion by 1 Jan 1941, another by May 1941 and the remaining 4 taken in hand that year. Project cancelled on outbreak of WW2.

Hawkins class
It was tentatively proposed to rearm Hawkins and Frobisher with 5.25" guns, This is what Aiden Dodson who wrote a book on the class recently had to say about this proposal:-

"It includes everything I've been able to find on these issues. We have quite a bit of detail on the 8in conversion-plan, including sketches. However, we have almost nothing on the 5.25in conversion plans, which seem to have been scrapped just before any drawings were produced (although I do include my own sketch of what the ships MIGHT have looked like).

It appears that the Munich Crisis meant that it was not sensible to tie up Hawkins and Frobisher for long refits (cf. the non-modernisation Hood), while the difficulty in producing enough 5.25in mountings for not only them but the Didos and King George Vs mean that something had to give - and Hawkins and Frobisher were what 'gave'. Rather, they were now simply to be given single 6in guns in the locations formerly occupied by the 7.5in guns at the outbreak of war - which was switched to reinstatement of the 7.5ins when the UK decided to abrogate the all naval treaties in September 1939. As it transpired, while Hawkins was indeed back in service before the end of the year with her old guns, Frobisher required much more work, which combined with higher priority work, and the need to do yet more work to reflect emerging requirements, to mean she wasn't back in service until 1942."

1939 Cruiser Programme
As noted it was to consist of 4 Fijis. Two were ordered from Portsmouth & Devonport in Aug 1939 but cancelled at the end of Sept. Bermuda & Newforundland were due to be ordered in March 1940 but that was brought forward with the outbreak of WW2. So with no European War all 4 would have gone ahead.

1940 Cruiser Programme
July 1939 talk was of 9 Fiji & Dido class but again quaestions about industry ability to accomodate this.



Anyway enough for tonight. If I have time tomorrow I might be able to add more. Came across some sub info.