Alternative Royal Navy during the Interwar period

Submarines
Part 1 - Requirements​

From the early 1920s to the middle 1930s the Admiralty wanted a "One Power Standard Fleet" and from the middle 1930s to until the outbreak of World War two the Admiralty wanted a "Two Power Standard Fleet". The "One Power Standard Fleet" was a fleet capable of fighting a war against one first class naval power (i.e. Japan). The "Two Power Standard Fleet" was a fleet capable of fighting a war against two first class naval powers (i.e. Germany and Japan).

The number of submarines that the Admiralty wanted was as follows:
  • In 1924 - 80 boats to be built at the rate of 8 per year.
  • In 1929 - 60 boats to be built at the rate of 6 per year.
  • In 1934 - 55 boats to be built at the rate of 4 per year.
  • In 1935 - 82 boats to be built at the rate of 7 per year.
Prior to 1930 all the submarines had to be under-age and a submarine became over-age when 10 years had elapsed since its date of completion. However, both London Naval Treaties said that a submarine was deemed to be "over-age" when 13 years had elapsed since the date of its completion.

The Washington Naval Treaty of 1922 didn't place any limits on the size and quantity of submarines. However, the First London Naval Treaty of 1930 limited the British Commonwealth, Japan and United States to 52,700 tons of submarines (standard displacement) each. (There were no submarine tonnage quotas for France and Italy because their Governments wouldn't accept one.) There were no quantitative limits on submarines from the beginning of 1937 because the Second London Naval Treaty of 1936 (which came into force on 01.01.37) abolished the tonnage quotas.
 
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Submarines
Part 2 - Submarine Construction 1922-39 in the "Real World".​

The Submarine Force in 1922

According to Conway's 1922-46 the British Empire had 82 submarines in 1922 with a total surface displacement of 77,264 tons.
  • 74 boats (66,722 tons) were completed 1914-21.
    • That is 2 C class (both RCN), one E class, one G class, 24 H class (including 2 RCN), 6 J class (all RAN), 9 K class, 26 L class, 3 M class and 2 R class.
    • The RN had 62, the RAN had 6 and the RCN had 4.
  • 8 boats (10,542 tons) were under construction.
    • That is 1 K class, 6 L class and X1.
    • They would be completed 1923-26.
The Submarine Force at 22.04.30

The First London Naval Treaty was signed on 22.04.30. At that date the British Commonwealth had 74 submarines (completed, building or authorised) with a total standard displacement of 69,949 tons.
  • 57 boats were completed 1917-30.
    • That is 14 H class, 1 K class, 30 L class, 2 M class, 1 old R class, 8 O-to-R class (including 2 RAN) and X1.
    • The RN had 55 and the RAN had 2.
    • They had a total standard displacement of 47,859 tons, which was about 5,000 tons less than the 52,700 tons of submarines that the British Commonwealth was allowed to have under the First London Naval Treaty.
    • According to the London Naval Treaty none of the 57 submarines were over-age, none were more than than 13 years old.
    • However, 36 were more than 10 years old and were therefore over-age according to the 10-Year Plan of 1924.
  • 17 boats (22,090 tons) were building or authorised.
    • That is 11 O-to-R class, 4 S class, 1 Porpoise class and 1 Thames class.
    • They would be completed 1930-33.
The Submarine Force at 31.12.36

When the First London Naval Treaty expired (31.12.36) the British Commonwealth had 66 submarines (completed, building and authorised) with a total standard displacement of 67,454 tons.
  • 52 boats had been completed 1918-36.
    • That is 9 H class, 10 L class, 18 O-to-R class, 10 S class, 3 Thames class and 2 Porpoise class. (The P class boat Poseidon was lost in 1931).
    • All belonged to the RN because the RAN transferred their 2 O class boats to the RN in 1931.
    • They had a total standard displacement of 52,959 tons which was nearly the same as the 52,700 tons of submarines that the British Commonwealth was allowed to have under the First London Naval Treaty.
    • 14 were more than 13 years old and were therefore over-age according to the London Naval Treaties.
    • 19 were more than 10 years old and were therefore over-age according to the 10-Year Plan of 1924.
  • 14 boats (14,495 tons) were building or authorised.
    • That is 2 S class, 5 T class, 3 U class and 4 Porpoise class.
    • They would be completed 1937-40.
The Submarine Force at 03.09.39

When Great Britain declared war on Germany (03.09.39) the British Commonwealth had 73 submarines (completed, building and projected) with a total standard displacement of 76,969 tons.
  • 57 boats had been competed 1918-39
    • That is 9 H class, 3 L class, 18 O-to-R class, 12 S class, 3 T class, 3 U class, 3 Thames class and 6 Porpoise class.
    • All belonged to the RN.
    • They had a total standard displacement of 59,529 tons, which was about 7,000 tons more than the 52,700 tons that the British Commonwealth was allowed to have under the First London Naval Treaty.
    • 11 were more than 13 years old and were therefore over-age according to the London Naval Treaties.
    • 18 were more than 10 years old and were therefore over-age according to the 10-Year Plan of 1924.
  • 16 boats (17,440 tons) were under construction or projected. However, only 12 of them were built.
    • 12 T class boats (13,080 tons) were under construction. All 12 were laid down before the end of 1938 and would be completed 1939-41.
    • 4 T class boats (4,360 tons) were in the 1939-40 Navy Estimates, but they hadn't been ordered before 03.09.39 and were included in the 24 submarines (5 S class, 7 T class and 12 U class) that were built under the War Emergency Programme.
Summary 1922-39

58 submarines were ordered by the Australian and British Governments between the Point of Departure (31.03.22) and when Great Britain declared war on Germany (03.09.39) as follows:

Submarines Ordered 1922-39.png ​

Notes
  • The O-to-R class boat built under the 1923-24 Estimates was the first O class boat.
  • The boats built under the 1924-25 Estimates were ordered and paid for by the Australian Government. They were completed in 1927 and transferred from the RAN to the RN in 1931.
  • In 1924 the Admiralty wanted to build 80 submarines at the rate of 8 per year over 10 years. However,
    • 6 O class boats were built under the 1926-27 Estimates instead of 8.
      • And.
    • 6 P class boats were built under the 1927-28 Estimates instead of 8.
  • By 1929 the requirement had been reduced from 80 to 60 submarines to be built at the rate of 6 per year over 10 years.
    • However, the number of submarines in the 1928-29 Estimates was reduced from 6 to 4 boats of the R class as a goodwill gesture before the First London Naval Conference.
      • And.
    • Only 21 submarines were built under the 1929-30 to 1935-36 Estimates, which was an average of 3 boats a year.
  • 8 boats were built under the 1936-37 Estimates (which was the first financial year of full-scale rearmament) and the plan was to order 7 boats a year from the 1937-38 Estimates onwards.
    • However, the Rearmament Programme created demand pull inflation and a balance of payments deficit.
    • As a result the number of submarines built under the 1938-39 Estimates was reduced from 7 boats to 3.
    • And the number of submarines to be built under the 1939-40 Estimates was reduced from 7 boats to 4.
    • But the 4 boats in the 1939-40 Estimates hadn't been ordered before the Declaration of War on Germany and it looks like they were included in the 24 submarines ordered in the War Emergency Programme.
  • Of the 58 boats ordered by 03.09.39.
    • 46 were completed between July 1927 and July 1939.
      • However, the P class boat Poseidon was lost in 1931, which reduced the number available on 03.09.39 from 46 to 45.
    • The other 12 were completed between 16.09.39 to 14.01.41.
 
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Submarines
Part 3 - Submarine Construction 1922-39 in this "Version of History".​

The Submarine Force in 1922

According to Conway's 1922-46 the British Empire had 82 submarines in 1922 with a total surface displacement of 77,264 tons.
  • 74 boats (66,722 tons) were completed 1914-21.
    • That is 2 C class (both RCN), one E class, one G class, 24 H class (including 2 RCN), 6 J class (all RAN), 9 K class, 26 L class, 3 M class and 2 R class.
    • The RN had 62, the RAN had 6 and the RCN had 4.
  • 8 boats (10,542 tons) were under construction.
    • That is 1 K class, 6 L class and X1.
    • They would be completed 1923-26.
That is exactly the same as the Submarine Force in 1922 in the "Real World".

The Submarine Force at 22.04.30

The British Commonwealth had 92 submarines (completed, building or authorised) with a total standard displacement of 92,199 tons. This was 18 boats and 22,250 tons more than the 74 submarines and 69,949 tons that it had in the "Real World".
  • However, all of the 18 extra boats were building or authorised so the total available at 22.04.30 was still 57 boats (47,859 tons) were completed 1917-30.
    • That is 14 H class, 1 K class, 30 L class, 2 M class, 1 old R class, 8 O-to-R class (including 2 RAN) and X1.
    • The RN had 55 and the RAN had 2.
    • 36 were more than 10 years old and were therefore over-age according to the 10-Year Plan of 1924.
  • The number of boats building or authorised was therefore increased from 17 boats (22,090 tons) to 35 boats (44,340 tons).
    • That is 19 O-to-R class, 10 S class, 3 Porpoise class and 3 Thames class.
    • They would be completed 1930-33.
In the "Real World" the RN and RAN had 57 submarines in service against a requirement for 60, which was 95% of the required number, although too many were over-age. In this "Version of History" the total was still 57 against a requirement for 80. Therefore, up to 23 of the 33 boats that were discarded between 1922 and 1930 in the "Real World" may have been retained in this "Version of History" to make up the numbers.

The Submarine Force at 31.12.36

The British Commonwealth had 109 submarines (completed, building and authorised) with a total standard displacement of 116,794 tons. This was 43 boats and 49,340 tons more than the 66 boats and 67,454 tons that existed at this date in the "Real World".
  • 85 boats (91,274 tons) had been completed 1918-36 against a requirement for 82 in the "Two Power Standard Fleet"of 1935.
    • That is 9 H class, 10 L class, 26 O-to-R class, 26 S class, 8 Thames class and 6 Porpoise class. (The P class boat Poseidon was lost in 1931).
    • All belonged to the RN because the RAN transferred their 2 O class boats to the RN in 1931.
    • 19 were more than 10 years old and were therefore over-age according to the 10-Year Plan of 1924.
  • 24 boats (14,495 tons) were building or authorised.
    • That is 6 S class, 5 T class, 3 U class and 10 Porpoise class.
    • They would be completed 1937-40.
The Submarine Force at 03.09.39

When Great Britain declared war on Germany (03.09.39) the British Commonwealth had 114 submarines (completed, building and projected) with a total standard displacement of 131,239 tons. This was 41 boats and 54,270 tons more than the 73 boats and 76,969 tons that existed that existed at this date in the "Real World".
  • 88 boats (102,899 tons) had been competed 1927-39 against a requirement for 82 in the "Two Power Standard Fleet"of 1935.
    • 26 O-to-R class, 32 S class, 3 T class, 3 U class, 8 Thames class and 16 Porpoise class.
    • All belonged to the RN.
    • 3 were more than 10 years old and were therefore over-age according to the 10-Year Plan of 1924.
  • 26 boats (28,340 tons) were under construction or authorised and all 26 were built.
    • 18 T class boats (13,080 tons) were under construction. All 18 were laid down before the end of 1938 and would be completed 1939-41.
    • 8 T class boats (8,720 tons) were in the 1939-40 Navy Estimates. Unlike the 4 boats that were in the "Real World's" 1939-40 Estimates but they had been ordered before 03.09.39 and would be completed in 1941.
    • In spite of the above the War Emergency Programme was still for 24 submarines (5 S class, 7 T class and 12 U class).
Summary 1922-39

115 submarines were ordered by the Australian and British Governments between the POD (31.03.22) and when Great Britain declared war on Germany (03.09.39) as follows:

Submarines Ordered 1922-39 - 8 Per Year.png ​

Notes
  • This is 57 boats more than (or nearly double) the 58 that were ordered in the "Real World" because a building rate of 8 per year was maintained from 1926-27 to 1939-40.
  • 56 boats were ordered in the 7 financial years 1929-30 to 1935-36 instead of 21 at the rate of 8 per year instead of 3 per year.
    • I arrived at the total of 8 Thames class, 16 Porpoise class and 32 S class (56 boats) by dividing the number of each class that was built in the "Real World" by 3 and then multiplying the answer by 8.
    • However, it's more likely that more 8 Thames class and less than 16 Porpoise class would have been built because 16 mine-laying submarines out of a total of 82 boats seems too many to me. For example the 82 submarines that were required in the "Two Power Standard Fleet" of 1935 included 9 mine-laying submarines.
  • The extra defence expenditure in the 14 Financial Years 1922-23 to 1935-36 meant that the British armaments industry was much bigger in the middle of the 1930s in this "Version of History" than it had been in the "Real World"which resulted in less demand pull inflation and a smaller balance of payments deficit in the second half of the 1930s.
    • As a result it was possible to build 8 boats under the 1938-39 Estimates instead of 3.
    • Furthermore, the 8 boats were in the 1939-40 Estimates instead of 4 and unlike them the 8 boats were ordered before 03.09.39 and completed before the end of 1941 instead of being included in the 24 boats in the War Emergency Programme.
    • In spite of the above 24 boats (5 S class, 7 T class and 12 U class) were still built under the War Emergency Programme.
  • It's also possible that 32 T class would have been ordered instead of 29 T class and 3 U class because 32 S class were built instead of 12 and some of the 20 extra boats may be used as training submarines. For example the 82 submarines that were required in the "Two Power Standard Fleet" of 1935 included 14 boats for training purposes (7 for submarine training and 7 for ant-submarine training).
  • Of the 115 boats ordered by 03.09.39.
    • 89 were completed between July 1927 and July 1939.
      • However, the P class boat Poseidon was lost in 1931, which reduced the number available on 03.09.39 from 89 to 88, but that's still 8 more than the 80 required in the 1924 Plan and 6 more than the 82 required in the "Two Power Standard Fleet".
    • The other 26 were completed between 16.09.39 and the end of 1941.
    • Except, that as 56 boats were built under the 1929-30 to 1935-36 Estimates instead of 21 the UK probably had the capacity to build more submarines than it did in the "Real World". Therefore, it's plausible that the 32 boats built under the 1936-37 to 1939-40 Estimates might be built in less time that the 18 boats that were built under the 1936-37 to 1937 Estimates in the "Real World".
 
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I am a bit concerned about the class mix, as there's a good number of small submarines in there and being a USN Pacific Fleet submarine sailor I don't like small submarines. That said, they may work well enough for interdicting coastal freight around Europe.
 
Scott Kenny said:
I am a bit concerned about the class mix, as there's a good number of small submarines in there and being a USN Pacific Fleet submarine sailor I don't like small submarines. That said, they may work well enough for interdicting coastal freight around Europe.
Click to expand...
Large submarines may be idea for operations on the biggest ocean in the world and fighting an enemy that imports most of its raw materials & all of its oil with a merchant marine which said enemy didn't take adequate measures to protect until it was too late & was too small for its needs in the first place.

It's a different story when operating in confined waters like the North Sea & Mediterranean, close to hostile air bases, your main target is the enemies' surface fleets and their much smaller & less important merchant marines are adequately to well protected. Or to put it another way large submarines operating in the North Sea and Mediterranean (especially the latter) were death traps.

The Royal Navy learned this the hard way. In June 1940 it was forced to send its large O-to-R class submarines from Singapore to the Mediterranean because there was nothing else to send. They were slaughtered by the Italians. That's the main reason why there weren't any submarines at Singapore when the Japanese attacked.

Practical experience revealed that the best design for the Mediterranean was the small U class which was originally designed to replace the remaining boats of the H class that were in service as training submarines.

Therefore, the Royal Navy needed a mix of large submarines for the Far East and small submarines for the North Sea & Mediterranean. This was what it tried to do in the "Real World" but it wasn't able to build either type in the required numbers. In this "Version of History" it was able to build more of each type, not necessarily in the required numbers, but certainly in considerably greater numbers.

***** ***** *****​

I've used 1,000 tons standard displacement as the cut-off point between large & small boats for the following and my source is Jane's 1939.

In the "Real World" the Royal Navy had 57 submarines on 03.09.39 of which 30 were large and 27 small.
  • That's a ratio of about 50:50.
  • The 30 large boats were 18 O-to-R class, 3 T class, 6 Porpoise class and 3 Thames class.
  • The 27 small boats were 9 H class, 3 L class, 12 S class and 3 U class.
In this "Version of History" there were 88 submarines on 03.09.39 (about 50% more than the "Real World") of which 53 were large and 35 small.
  • That's a ratio of about 60:40.
  • The 53 large boats were 26 O-to-R class, 3 T class, 8 Thames class and 16 Porpoise class.
  • The 35 small boats were 32 S class and 3 U class
Furthermore, 12 of the 57 submarines were over-age in the "Real World" and only 3 of the 88 boats were over-age in this "Version of History". Plus in the "Real World" a submarine became over-age 13 years after its date of completion and in this "Version of History" a submarine became over-age 10 years after its date of completion. If I'd used the 13-year rule none of the 88 boats available on 03.09.39 in this "Version of History" would have been over-age.

Finally, in this "Version of History" we also have 26 large submarines of the T class under construction or on order at 03.09.39 instead of 12 large submarines of the T class under construction or on order at that date in the "Real World".

So that makes a total of 53 large boats in service on 03.09.39 plus 26 under construction or on order in this "Version of History" which is a great improvement over the 30 large boats in service and 12 under construction on that date in the "Real World". By contrast I've only increased the number of small boats at 03.09.39 from 27 to 35 with none under construction or on order in either version of history. Although all 35 small boats in this "Version of History" were under-age and only 15 of the 27 boats in service on 03.09.39 in the "Real World" were under-age.

***** ***** *****

For What It's World this what the 82 Submarines in the "Two Power Standard Fleet" were for.
The source is a Cabinet Paper called
DEFENCE EXPENDITURE IN FUTURE YEARS.
INTERIM REPORT BY THE MINISTER FOR CO-ORDINATION OF DEFENCE.
Dated December, 1937
(National Archives Catalogue Reference: CAB/24/273 Image Reference:0041)

Cabinet Paper - Submarines 3.png
​
Half of the 14 training submarines were for submarine training (which I think means training submarine crews) and the other half were for ASW training (which I think means ASW training for the surface fleet).
 
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@NOMISYRRUC Like I said, that concern was very much me being a PACFLT submariner.

I know I am currently considering a design for a "Very Large SEAL Delivery Vehicle" aka a modern diesel boat for the USN. Mostly because even a 360ft LA or Virginia class boat is too big for the Baltic and Black Seas. Arguably for the ECS and SCS as well.
 
Submarines
Part4 – What were the other naval powers doing?​

There were two reasons why so many submarines were built in this “Version of History”. The first was that government revenue and expenditure was at 1921-22 levels from the 1922-23 financial year to the middle 1930s, because there was no Geddes Axe. The second reason was that there was a different 1930 London Naval Treaty which had no tonnage quotas for submarines, cruisers and destroyers. Otherwise, the British Commonwealth would have been limited to a maximum of 52,700 tons of submarines between 1930 and1936.

However, the real 1930 London Naval Treaty limited Japan and the United States to 52,700 tons of submarines as well and in this “Version of History” were also free to build as many submarines (and cruisers & destroyers) as they liked too because they weren't subject to tonnage quotas for submarines (and cruisers &destroyers) either. Although they may not have built any more submarines in practice and might have actually built less between 1930 and 1936.

In the “Real World” Japan built 13 submarines under their First and Second Fleet Replenishment Programmes, which were designed to bring the IJN to the strength permitted by the Treaty by the end of 1936. This is the number of submarines that I think would have been built in this "Version of History" because the number of unregulated ships that the IJN wanted in the “Real World” was unaffordable therefore I think that Japan would not have been able to build more submarines in this “Version of History” without building less of something else. Plus Japan laid down 6 capital ships 1931-36 in this “Version of History” because 1930 London Naval Treaty does not extend the battleship building holiday from the end of 1930 to the end of 1936 in this “Version of History”. As will be explained in a future post, I think the money spent on modernising the existing capital ships in the "Real World" will be enough to pay for the new ships in this "Version of History", but if I'm wrong new construction of other types of warship including submarines will have to be cut.

As far as I know the United States wanted parity with the British Commonwealth in all classes of warship and in spite of the Depression it had the money to so. However, Congress might not authorise the necessary expenditure, but if it did provide the money the looser would have been the IJN rather than the RN because there was little chance of a war between the UK & USA and a very good chance that the UK & USA would have been allies in a war against Japan.

The Real-Treaty didn't have tonnage quotas for submarines (and cruisers & destroyers) for France and Italy, therefore I think they'd have built exactly the same number of submarines (and cruisers & destroyers) between 1930 and 1936 in this “Version of History”.

All other things being equal the larger British Commonwealth submarine force of this “Version of History” would have allowed Germany to have more submarines too, because the Anglo-German Naval Agreement allowed Germany to have 45% of the British Commonwealth's tonnage of submarines (plus an escalator clause allowing an increase to 100%). Thus Germany could have built more submarines between 1935 and the abrogation of the Agreement in1939. However, I think that in this “Version of History” the Agreement would have limited Germany to 35% of the British Commonwealth's submarine tonnage (with no escalator clause) because 35% was the tonnage limit for all classes of surface warship under the Real-Agreement. Furthermore, Germany may not have had the industrial capacity to build the extra submarines because it had a lot of trouble building surface warships to the limits allowed by the Agreement in the “Real World”.
 
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Cruisers​

Introduction

In the "Real World" the British Commonwealth had 65 cruisers on 03.09.39 plus another 27 that were building, on order or planned. However, in this "Version of History" the British Commonwealth had 82 cruisers on that date plus another 28 that were building, on order or planned. Two things made this possible. Firstly there was no Geddes Axe and British Government taxation & spending were maintained at 1921-22 levels from 1922-23 to the middle 1930s. Secondly, there was no 1930 London Naval Treaty or a less restrictive Treaty which didn't have tonnage quotas for cruisers (or submarines or destroyers).

Cruiser Requirements

In the "Real World" the Admiralty wanted 70 cruisers (of which 10 could be over-age) from 1924 to the middle 1930s to fight a war against one first class naval power (Japan) and 100 cruisers (of which 15 could be over-age) from the middle 1930s to 03.09.39 to fight a war against two first class naval powers (Germany and Japan). The 70 cruiser force consisted of 25 fleet cruisers and 45 trade protection ships. The 100 cruiser force consisted of 55 fleet cruisers & 45 trade protection and the 55 fleet cruisers included 30 in home waters & 25 in the Far East. But the First London Naval Treaty of 1930 limited the British Commonwealth to 339,000 tons of cruisers which was enough to maintain a force of 50 ships. The Second London Naval Treaty which came into effect on 01.01.37 abolished the cruiser tonnage quota (and the submarine tonnage quota & the destroyer tonnage quota) but there was only time to increase the number of cruisers from the 56 that actually existed at the end of 1936 to 65 by 03.09.39 which was done by not scrapping any ships during the intervening period.

In 1924 a cruiser became over-age 15 years after its date of completion, which required a building rate of 4 ships a year to maintain a force of 60 under-age cruisers, but the Government wouldn't provide the money to build 4 ships a year. Therefore, the Admiralty increased the age limit to 20 years after a cruiser's date of completion in 1926. The new age limit required a building rate of 3 ships a year to maintain a force of 60 under-age cruisers and 4¼ ships a year (i.e. 4 a year plus a 5th every leap year) to maintain a force of 85 under-age cruisers. The 20 year age limit became international law in 1930 when the First London Naval Treaty said that a surface vessel exceeding 3,000 tons but not exceeding 10,000 tons standard displacement was deemed to be "over-age" after 16 years if laid down before 01.01.20 and after 20 years if laid down after 31.12.19. This rule was carried over into the Second London Naval Treaty of 1936.

In terms of numbers the Admiralty's cruiser requirements were exactly the same as the "Real World" in this "Version of History", but the age limit wasn't increased from 16 to 20 years until the middle 1930s. This was possible because the Government spent more money on defence between 01.03.22 & 31.03.36 and there was no 1930 London Naval Treaty or one that didn't have tonnage quotas for cruisers (and submarines & destroyers).

Cruiser Construction 1924-36

According to Conway's 1922-46 the British Empire had 50 cruisers at the end of 1921 which were completed 1909-21. However, one of the 50 was the Hawkins class cruiser Vindictive which was completed as an aircraft carrier in 1918 & wouldn't be converted back into a cruiser until 1923-25 and the Hawkins class cruiser Raleigh which would be wrecked on 08.08.22. Another 8 cruisers were under construction at the end of 1921 and they would be completed 1922-26. Thus there were 57 cruisers at the end of 1926 including 4 that were overage. Except that 7 were broken up 1923-26 which reduced the total to 50 of which 3 were over age.

By mid-1923 (according to Freidman) the Board of Admiralty was calling for 70 cruisers (of which 10 could be overage) to be ready by the target modernisation date of 1929. The Director of Pans proposed a building programme of eight 10,000-ton cruisers in 1924, 1925 & 1926 and 4 in each succeeding year. He assumed, also, a 3-year building time. That would give 28 large cruisers in 1929 and a total of 59 under-age ships at that time. He didn't say so but the 28 large cruisers in 1929 were the 4 surviving ships of the Hawkins class and the twenty-four 10,000 ton ships class laid down 1924-26 & completed 1927-29. However, according to my calculations there would have been 66 underage cruisers at the end of 1929. That is 42 completed 1914-26 and 24 County class completed 1927-29.

However, 37 cruisers were actually laid down at an average rate of 3 per year 1924-36 (and completed 1928-39) in the "Real World" which was enough to maintain a force of 70 cruisers (including 60 less than 20 years of age). 64 cruisers were actually laid down at an average rate of 5 per year 1924-36 (and completed 1928-39) in this "Version of History" which was enough to maintain a force of 70 cruisers (including 60 less than 15 years of age) because the ships were being built at the rate proposed in mid-1923.

The British Commonwealth had 56 cruisers at the end of 1936 in the "Real World" including 20 that were more than 15 years old. Another 9 were under construction. They had been laid down 1934-36 and would be completed 1937-39. None of the existing ships would be discarded 1937-39 so the total at 03.09.39 was 65 cruisers including 25 that were more than 15 years old.

The British Commonwealth had 70 cruisers at the end of 1936 in this "Version of History" including 11 that were more than 15 years old. Another 12 were under construction. They had been laid down 1934-36 and would be completed 1937-39. None of the existing ships would be discarded 1937-39 so the total at 03.09.39 was 82 cruisers including 15 that were more than 15 years old.

Cruiser Construction 1936-39

In the "Real World" a total of 27 cruisers were laid down 1937-40 & completed 1940-44. This included 21 ships that were built under the 1936-37 to 1939-40 Navy Estimates and 6 ships built under the War Emergency Programme. Each ship took an average of 3 years to build.

In this "Version of History" 28 cruisers were laid down 1937-40 & completed 1940-42. This included 24 ships that were built under the 1936-37 to 1939-40 Navy Estimates and 4 ships built under the War Emergency Programme. Each ship took an average of 2½ years to build.

The "Version of History" ships were built after the cruiser requirement was increased from 70 (including 10 over age) to 100 (including 15 over age) with the new target to be reached by 31.03.42. They were also built after the age limit for cruisers was increased from 15 to 20 years and 14 of the 82 cruisers existing or under construction at the end of 1936 would be overage on 31.03.42. Thus 18 additional cruisers had to be laid down by March 1939 to meet the new target. This was done adding 4 ships to the 4 already being built under the 1936-37 Navy Estimates, building 8 ships under the 1937-38 Estimates and 8 more under the 1938-39 Estimates. This made a total of 20 ships (against a requirement for 18) so there would have been 12 underage cruisers on 31.03.42 instead of 14. The last 6 of these cruisers were actually laid down after 31.03.39 but were completed before 31.03.42 because they took about 2½ years each to build.

4 ships were built under the 1939-40 Estimates and another 4 were built under the War Emergency Programme. When they were ordered the plan was that they would be laid down by 31.03.40 and completed by 31.03.43. They were actually laid down between November 1939 & March 1940 and completed between May & September 1942.

Thus the total at 03.09.39 was 82 cruisers completed 1918-39 (including 10 over 20 years of age) with another 28 under construction or on order which would be completed 1940-42.

What Type of Cruiser?

I think 32 County class ships would have been ordered under the 1924-25 to 1928-29 Building Programmes instead of the 15 ships (13 County and 2 York class) that were built under these programmes in the "Real World". Australia paid for 2 of the County class ships in both "Versions of History".

I think 32 Edinburgh class ships would have been ordered under the 1929-30 to 1936-37 Building Programmes instead of the 22 ships (5 Leander, 3 Amphion, 4 Arethusa, 5 Southampton, 3 Gloucester and 2 Edinburgh class) that were build under these programmes in the "Real World". Firstly, I think the RN would still decide that it preferred 6in guns to 8in guns for its cruisers, plus budgets were less restricted so if could continue to build 10,000 ton cruisers in the numbers it required and the ALT-1930 London Naval Treaty didn't have tonnage quotas for cruisers (or submarines or destroyers) so there was no legal impediment to prevent it from reaching its target of 700,000 tons of cruisers, i.e. 70 ships displacing 10,000 tons each.

The 28 cruisers that were laid down 1937-40 and completed 1940-42 were additional ships of the Edinburgh class. This was possible because of the extra building capacity which had been created/maintained 1924-36 in this "Version of History" and because the 1936 London Naval Treaty of didn't reduce the size limit for cruisers from 10,000 tons to 8,000 tons.

The RN did have a requirement for smaller cruisers to work with the destroyer flotillas in the main fleets. However, I've decided to concentrate on larger ships for industrial reasons. For example, I think it would have been easier to build more triple 6" turrets than twin 5.25in turrets. This was partially because the former was already in production and also because the 16 Dido class ordered IOTL required 80 turrets (although not all were built) and 16 Edinburgh class needed 64 turrets.

The Old Cruisers

In the "Real World" the RN & RAN had 28 "old" cruisers at 03.09.39 consisting of Adelaide, 13 C class, 8 D class, 2 E class and 4 Hawkins class. 25 out of 28 were more than 15 years old and 19 out of 28 were more than 20 years old. As far as I know the plan was to convert the 10 newest C class to AA ships. In the end one of the 3 oldest & 7 out of the 10 newest were converted. This may have been because some of the newer ships were sunk before they could be converted. Rearming the 8 D class with 4.5in DP guns was considered, but the war stopped the programme, although Delhi was rearmed with 5 single American 5in DP guns & 2 Mk 37 FCS. One of the Hawkins class had its 7.5in guns replaced by nine single 6in guns & also had eight 4in AA guns in 4 twin mountings fitted and World War II prevented the other 3 from being modernised along similar lines. I don't remember any plans to rearm the E class in Friedman and haven't checked.

In this "Versions of History" the RN had 18 "old" cruisers at 03.09.39 consisting of 4 C class, 8 D class, 2 E class & 4 Hawkins class. 15 out of 18 were more than 15 years old and 10 out of 18 were more than 20 years old. All 4 C class and all 8 D classes had been rearmed with twin 4in AA guns. All 4 Hawkins class had been rearmed with nine single 6in guns and had also had eight 4in AA guns in 4 twin mountings fitted. Both E class had received eight 4in AA guns in 4 twin mountings by 03.09.39.

I did suggest rebuilding the Hawkins and E class along the lines of the Japanese Furukata class 1931-39 in the "Optimize the RN for WWII" thread on alternatehistory.com earlier this year as a way of preserving some infrastructure and increasing the number of modern cruisers. I'm not doing it in this thread for three reasons.
  1. Although I have more money to spend in this thread I think there isn't enough money for this and the 10 battleships that I want to lay down 1931-36. (Which can be done because there wasn't a 1930 London Naval Treaty in this "Version of History" or if the was it didn't extend the battleship building holiday from the end of 1930 to the end of 1936.
  2. There is less need to rebuild them as 64 cruisers were laid down 1924-36 in this thread compared to 52 in the other thread.
  3. Prior to 1936 the first pair of Hawkins class would become overage 1933-34, followed by the second pair in 1939-40 and the E class in 1941. Even after the age limit was increased to 20 years and the size of the cruiser force was increased to 100 ships they'd be replaced between April 1942 & March 1945 by the 12 cruisers that were to be built under the 1939-40 to 1941-42 Estimates. Therefore, they wouldn't be in service for long enough to make the rebuilds cost effective. That's also why I've rearmed the D class with 4in AA guns instead of the 4.7in DP gun which I want the RN to standardise on. The heavier guns would have been more expensive and required more extensive modifications to the ship, which would have taken more time cost more money.
Organisation of the Cruiser Force

In the "Real World" the Third Report of the D.R.C. (written in February 1936) recommended that the number of cruisers be increased from 50 (44 RN, 4 RAN & 2 NZ Div) to 70 (64 RN, 4 RAN & 2 NZ Div). It also recommended that the number of RN cruisers in full commission be increased from 30 to 44 which would allow the 7 existing cruiser squadrons to be increased from 4 ships to 5 and a second cruiser squadron (of 5 ships) to be formed in the Home Fleet.
The war training of the Home Fleet is handicapped by having only one cruiser squadron in that fleet, and squadrons abroad are handicapped by the absence of ships returning home for refits and re-commissioning.
Click to expand...
The normal number of ships in a fleet cruiser squadron has in the past always been five, and was only reduced in 1930-31 as an economy measure.
Click to expand...
The 14 extra cruisers would be distributed as follows:

CAB.024.259 (0026) 3rd DRC Report Cruiser Requirements Part 2.png ​

Except, that there were 4 cruiser squadrons on the foreign stations and increasing them from 4 to 5 ships each produces a surplus of 2 ships.

In this "Versions of History" there were 70 cruisers from 1929 to 1936 including 64 in the RN (44 in full commission & 20 in refit or reserve), 4 in the RAN and 2 in the NZ Division.

The 100 cruiser force included 10 maintained by the Dominions. I don't know how many of the remaining 90 would have been in full commission, refit or reserve. My guess is that it would have been 62 in full commission and 28 in refit or reserve. About 70% of the 64 RN cruisers in the 70-ship force were to be in full commission and 62 allows or 12 squadrons of 5 ships and 2 flagships for the destroyer flotillas in the main fleets.

The 65 cruisers in the Royal Navies at the outbreak of war included 8 maintained by the Dominions. That is the RAN had 6 and the NZ Division had 2. There would also have been 8 Dominion cruisers in this "Version of History" but the RAN would have had 4 Edinburgh class instead of Adelaide & the 3 Amphions and the NZ Division would have had 2 Edinburgh class instead of 2 Leanders.

An Alternative Battle of the River Plate

Therefore, this "Version of History's" Battle of the River Plate would have been the Real-Graff Spee fighting 4 RN & NZ Division ships instead of 3 consisting of 2 County and 2 Edinburgh class ships instead of one York and 2 Leander class ships with a total of 40 guns (16 x 8in & 24 x 6in) vice 22 (6 x 8in & 16 x 6in). My guess is that Graff Spee would have been quickly overwhelmed by the British ships and sunk before she could make Montevideo. Furthermore, she would have done less damage in return to the British ships than was done in the "Real World".

Cruiser Construction by the other Naval Powers

Starting with the easy ones...

France and Italy

The size of the French and Italian cruiser (and submarine and destroyer) forces wasn't limited by the Real-1930 London Naval Treaty so I think they'd build 19 cruisers each in both "Versions of History". Neither nation had the money to build more cruisers in this "Version of History". Furthermore, a shortage of slipways prevented France from building more even if it wanted to and in fact delayed the construction of some of the ships (not just cruisers) that were built in the "Real World" so France couldn't have built more cruisers in this "Version of History" even if it wanted to.

I think that the cruisers built in the 1920s in this "Version of History" would have been built to the same designs as the "Real World" because the British only built heavy cruisers in both "Versions of History". However, both navies may have built 10,000 ton light cruisers to match the cruisers of that type the British built in place of the Leander, Amphion & Arethusa classes. Therefore, France might have built 7 & ordered 3 ships of this type instead of the Emile Bertin, La Galissonniere & De Grasse classes and Italy might have built 6 & ordered 2 ships of this type instead of the Montecuccoli, Duca D'Aosta, Abruzzi & Ciano classes.

Germany

The Reichsmarine/Kriegsmarine was screwed good and proper in this "Version of History" because before 1935 Germany was limited by the Treaty of Versailles to eight 6,000 ton light cruisers and after 1935 didn't have the industrial capacity to build more cruisers. Therefore, it would have been overwhelmed by the British Commonwealth's larger cruiser force.

The Anglo-German Naval Agreement of 1935 in both "Versions of History" allowed Germany to have 35% of the British Commonwealth's tonnage of surface warships. In 1935 that allowed Germany to have 245,000 tons of cruisers in 1935 because the British were working towards a force of seventy 10,000 ton ships for a total of 700,000 tons. This increased to an allowance of 350,000 tons when the British decided to work to a total of one hundred 10,000 ton cruisers for a total of one million tons.

Therefore, in 1935 Germany had the right to build 11 Hipper class cruisers (35% of 320,000 tons is 112,000 tons) instead of 5 and another 97,400 tons of 6in gunned cruisers (35% of 380,000 is 133,000 tons less the 35,600 tons of 6in cruisers they already had). This jumped to 112,000 tons of 8in cruisers and 238,000 tons of 6in gunned cruisers in 1936 when the British Government announced its new target of a million tons of cruisers (100 ships each displacing 10,000 tons) of which 32 would still be armed with 8in guns and 68 would be armed with 6in guns.

However, Germany didn't have the industrial capacity to build any more cruisers in this "Version of History" so they still had 8 cruisers on 03.09.39 (and were only able to complete one more) while the British Commonwealth had another 17 for a total of 82 instead of 65. Plus the total included 64 new cruisers instead of 37 and 14 of the new cruisers had heavier armaments.

Japan

Japan was free to build as many cruisers as it wanted between 1930 and 1936 in this "Version of History" provided that they displaced no more than 10,000 tons and were armed with 8in or smaller guns. However, I believe that it didn't have the money or infrastructure to build more than the 6 ships that were built under the First and Second Fleet Replenishment Programmes in the "Real World". Furthermore, Japan might not be able to build that many cruisers in this "Version of History" because it also lays down 6 capital ships 1931-36 (as was allowed by the Washington Naval Treaty) because the 1930 London Naval Treaty doesn't extend the battleship building holiday from the end of 1930 to the end of 1936 in this "Version of History". My guess is that the money saved from not rebuilding the 10 existing battleships in this "Version of History" will be enough to pay for the 6 new capital ships. However, if I'm wrong fewer submarines, cruisers and destroyers would have been built 1930-36 to provide the extra money.

However, the cruisers that were built in this "Version of History" would have been additional Takao class ships instead of the "Real World's" Mogami and Tone class cruisers. On the other hand the Japanese had to rebuild the Mogami class twice. First to strengthen their weak hulls and second when the 6in guns they were completed with were replaced with 8in guns. My guess is that the first rebuilding won't be needed because they would have had incorporated the lessons learned from the Takao class ships that were built in the "Real World" and the second rebuilding won't be necessary because they were built with 8in guns. Avoiding the two rebuilds would have given the IJN money and dockyard space that it could have used to build other ships.

The 2 Ibuki class would have been additional Takao class ships in this "Version of History" too. Japan formed its heavy cruisers into divisions of 4 ships and the plan was that they and the 2 Tone class would have formed a fifth full-strength heavy cruiser division. The IJN wanted them built under the Third Fleet Replenishment Programme of 1937 but a shortage of money and building capacity delayed this for 4 years and they were eventually ordered as part of the Rapid Naval Armaments Supplementary Programme of 1941. That's one of the reason why I think Japan could not have built more cruisers 1930-36 even if the 1930 London Naval Treaty allowed it to.

Japan also built some smaller cruisers of the Agano and Oyodo classes to work with its destroyers and submarines in the "Real World". These were built after the Japan left the Treaty System so all other things being equal there was not change to the number built. However, the RN was building more Edinburgh class instead of the Dido class in this "Version of History" and the USN may be building a Super Atlanta or more Baltimore & Cleveland class light cruisers instead of the Real-Atlanta class which were their destroyer support cruisers. Therefore, the IJN might want a "Super Agano" with nine 6in in 3 triple turrets instead of the Real-Agano with six 6in guns in 3 twin turrets or a Takao class cruiser armed with fifteen 6in guns in 5 triple turrets instead of ten 8in guns in 5 twin turrets.

The United States

The USA was free to build as many cruisers as it wanted between 1930 and 1936 in this "Version of History" provided that they displaced no more than 10,000 tons and were armed with 8in or smaller guns. Furthermore, it didn't have the financial & infrastructure restrictions that I think would have prevented Japan from building more than 6 cruisers in this "Version of History". However, Congress might not have provided the money in spite of the US Government's aspiration for naval parity with the British Commonwealth in all classes of warship and in spite of Britain completing 64 cruisers 1927-39 instead of 37 in this "Version of History". My guess is that Congress would have provided the money to lay down 10 capital ships 1931-36 (as was allowed by the Washington Naval Treaty) because the 1930 London Naval Treaty doesn't extend the battleship building holiday from the end of 1930 to the end of 1936 in this "Version of History" but it wouldn't have provided the money for more cruisers (or destroyers or submarines) and might even have provided less money for cruiser (and destroyer and submarine) construction.

This is probably a bit of wishful thinking, but the this "Version of History" version of the Cleveland class light cruisers had the Baltimore class heavy cruisers hull and machinery which allowed them to carry a fifth triple 6in gun turret. As I understand it the Cleveland class began as an 8,000 ton design (as per the terms of the Real-1936 London Naval Treaty) but grew into the 10,000 ton design that was actually built. Therefore, in this "Version of History" the class began as a 10,000 ton design (as per the terms of the Alternative-1936 London Naval Treaty) but grew into the 13,600 ton design that was actually built.

6 Cleveland class cruisers were converted into guided missile cruisers in both "Versions of History" but the ships converted in this "Version of History" had larger hulls which allowed more guns to be retained or a second Terrier or Talos launcher to be fitted. The resulting ships might have resembled Boston and Canberra, except that they had three triple 6in turrets forward instead of two triple 6in turrets forward. Unfortunately, in both "Versions of History", the cost of the Vietnam War prevented them from having another refit in the late 1960s in which new radars & electronics would have fitted and their guided missile systems would have been modernised.

The 9 Independence class light fleet carriers of this "Version of History" were more capable ships because they were effectively converted Baltimore class heavy cruisers instead of converted Cleveland class light cruisers and therefore had longer & beamier hulls. This might not have made much difference in World War II, but it would have made them more useful after the war, especially for the French Navy which received 2 in the 1950s and the Spanish Navy which received one in the 1960s.

There might not have been an Atlanta class anti-aircraft cruiser in this "Version of History" or at least they might have been built to a different design. The Real-Atlanta class (in common with the British Dido class and Japanese Agano class) was designed to work with the destroyer flotillas (hence the small size and large number of rapid fire guns) and replace the Omaha class light cruisers currently used in that role. However, with the RN building more Edinburghs instead of the Didos and the IJN possibly building a larger & more powerful version of the Agano class or versions of the Takao class armed with fifteen 6in guns the USN may have decided that a larger and more heavily armed version of Atlanta was needed or they should build more Cleveland class cruisers instead.

The End of Cruisers
But NOMISYRRUC will return with Destroyers

Which hopefully will take a lot less time to write
And not be six pages of A4 long in twelve part Times New Roman.​
 
Last edited:
NOMISYRRUC said:
Cruisers​

Introduction

In the "Real World" the British Commonwealth had 65 cruisers on 03.09.39 plus another 27 that were building, on order or planned. However, in this "Version of History" the British Commonwealth had 82 cruisers on that date plus another 28 that were building, on order or planned. Two things made this possible. Firstly there was no Geddes Axe and British Government taxation & spending were maintained at 1921-22 levels from 1922-23 to the middle 1930s. Secondly, there was no 1930 London Naval Treaty or a less restrictive Treaty which didn't have tonnage quotas for cruisers (or submarines or destroyers).

Cruiser Requirements

In the "Real World" the Admiralty wanted 70 cruisers (of which 10 could be over-age) from 1924 to the middle 1930s to fight a war against one first class naval power (Japan) and 100 cruisers (of which 15 could be over-age) from the middle 1930s to 03.09.39 to fight a war against two first class naval powers (Germany and Japan). The 70 cruiser force consisted of 25 fleet cruisers and 45 trade protection ships. The 100 cruiser force consisted of 55 fleet cruisers & 45 trade protection and the 55 fleet cruisers included 30 in home waters & 25 in the Far East. But the First London Naval Treaty of 1930 limited the British Commonwealth to 339,000 tons of cruisers which was enough to maintain a force of 50 ships. The Second London Naval Treaty which came into effect on 01.01.37 abolished the cruiser tonnage quota (and the submarine tonnage quota & the destroyer tonnage quota) but there was only time to increase the number of cruisers from the 56 that actually existed at the end of 1936 to 65 by 03.09.39 which was done by not scrapping any ships during the intervening period.

In 1924 a cruiser became over-age 15 years after its date of completion, which required a building rate of 4 ships a year to maintain a force of 60 under-age cruisers, but the Government wouldn't provide the money to build 4 ships a year. Therefore, the Admiralty increased the age limit to 20 years after a cruiser's date of completion in 1926. The new age limit required a building rate of 3 ships a year to maintain a force of 60 under-age cruisers and 4¼ ships a year (i.e. 4 a year plus a 5th every leap year) to maintain a force of 85 under-age cruisers. The 20 year age limit became international law in 1930 when the First London Naval Treaty said that a surface vessel exceeding 3,000 tons but not exceeding 10,000 tons standard displacement was deemed to be "over-age" after 16 years if laid down before 01.01.20 and after 20 years if laid down after 31.12.19. This rule was carried over into the Second London Naval Treaty of 1936.

In terms of numbers the Admiralty's cruiser requirements were exactly the same as the "Real World" in this "Version of History", but the age limit wasn't increased from 16 to 20 years until the middle 1930s. This was possible because the Government spent more money on defence between 01.03.22 & 31.03.36 and there was no 1930 London Naval Treaty or one that didn't have tonnage quotas for cruisers (and submarines & destroyers).

Cruiser Construction 1924-36

According to Conway's 1922-46 the British Empire had 50 cruisers at the end of 1921 which were completed 1909-21. However, one of the 50 was the Hawkins class cruiser Vindictive which was completed as an aircraft carrier in 1918 & wouldn't be converted back into a cruiser until 1923-25 and the Hawkins class cruiser Raleigh which would be wrecked on 08.08.22. Another 8 cruisers were under construction at the end of 1921 and they would be completed 1922-26. Thus there were 57 cruisers at the end of 1926 including 4 that were overage. Except that 7 were broken up 1923-26 which reduced the total to 50 of which 3 were over age.

By mid-1923 (according to Freidman) the Board of Admiralty was calling for 70 cruisers (of which 10 could be overage) to be ready by the target modernisation date of 1929. The Director of Pans proposed a building programme of eight 10,000-ton cruisers in 1924, 1925 & 1926 and 4 in each succeeding year. He assumed, also, a 3-year building time. That would give 28 large cruisers in 1929 and a total of 59 under-age ships at that time. He didn't say so but the 28 large cruisers in 1929 were the 4 surviving ships of the Hawkins class and the twenty-four 10,000 ton ships class laid down 1924-26 & completed 1927-29. However, according to my calculations there would have been 66 underage cruisers at the end of 1929. That is 42 completed 1914-26 and 24 County class completed 1927-29.

However, 37 cruisers were actually laid down at an average rate of 3 per year 1924-36 (and completed 1928-39) in the "Real World" which was enough to maintain a force of 70 cruisers (including 60 less than 20 years of age). 64 cruisers were actually laid down at an average rate of 5 per year 1924-36 (and completed 1928-39) in this "Version of History" which was enough to maintain a force of 70 cruisers (including 60 less than 15 years of age) because the ships were being built at the rate proposed in mid-1923.

The British Commonwealth had 56 cruisers at the end of 1936 in the "Real World" including 20 that were more than 15 years old. Another 9 were under construction. They had been laid down 1934-36 and would be completed 1937-39. None of the existing ships would be discarded 1937-39 so the total at 03.09.39 was 65 cruisers including 25 that were more than 15 years old.

The British Commonwealth had 70 cruisers at the end of 1936 in this "Version of History" including 11 that were more than 15 years old. Another 12 were under construction. They had been laid down 1934-36 and would be completed 1937-39. None of the existing ships would be discarded 1937-39 so the total at 03.09.39 was 82 cruisers including 15 that were more than 15 years old.

Cruiser Construction 1936-39

In the "Real World" a total of 27 cruisers were laid down 1937-40 & completed 1940-44. This included 21 ships that were built under the 1936-37 to 1939-40 Navy Estimates and 6 ships built under the War Emergency Programme. Each ship took an average of 3 years to build.

In this "Version of History" 28 cruisers were laid down 1937-40 & completed 1940-42. This included 24 ships that were built under the 1936-37 to 1939-40 Navy Estimates and 4 ships built under the War Emergency Programme. Each ship took an average of 2½ years to build.

The "Version of History" ships were built after the cruiser requirement was increased from 70 (including 10 over age) to 100 (including 15 over age) with the new target to be reached by 31.03.42. They were also built after the age limit for cruisers was increased from 15 to 20 years and 14 of the 82 cruisers existing or under construction at the end of 1936 would be overage on 31.03.42. Thus 18 additional cruisers had to be laid down by March 1939 to meet the new target. This was done adding 4 ships to the 4 already being built under the 1936-37 Navy Estimates, building 8 ships under the 1937-38 Estimates and 8 more under the 1938-39 Estimates. This made a total of 20 ships (against a requirement for 18) so there would have been 12 underage cruisers on 31.03.42 instead of 14. The last 6 of these cruisers were actually laid down after 31.03.39 but were completed before 31.03.42 because they took about 2½ years each to build.

4 ships were built under the 1939-40 Estimates and another 4 were built under the War Emergency Programme. When they were ordered the plan was that they would be laid down by 31.03.40 and completed by 31.03.43. They were actually laid down between November 1939 & March 1940 and completed between May & September 1942.

Thus the total at 03.09.39 was 82 cruisers completed 1918-39 (including 10 over 20 years of age) with another 28 under construction or on order which would be completed 1940-42.

What Type of Cruiser?

I think 32 County class ships would have been ordered under the 1924-25 to 1928-29 Building Programmes instead of the 15 ships (13 County and 2 York class) that were built under these programmes in the "Real World". Australia paid for 2 of the County class ships in both "Versions of History".

I think 32 Edinburgh class ships would have been ordered under the 1929-30 to 1936-37 Building Programmes instead of the 22 ships (5 Leander, 3 Amphion, 4 Arethusa, 5 Southampton, 3 Gloucester and 2 Edinburgh class) that were build under these programmes in the "Real World". Firstly, I think the RN would still decide that it preferred 6in guns to 8in guns for its cruisers, plus budgets were less restricted so if could continue to build 10,000 ton cruisers in the numbers it required and the ALT-1930 London Naval Treaty didn't have tonnage quotas for cruisers (or submarines or destroyers) so there was no legal impediment to prevent it from reaching its target of 700,000 tons of cruisers, i.e. 70 ships displacing 10,000 tons each.

The 28 cruisers that were laid down 1937-40 and completed 1940-42 were additional ships of the Edinburgh class. This was possible because of the extra building capacity which had been created/maintained 1924-36 in this "Version of History" and because the 1936 London Naval Treaty of didn't reduce the size limit for cruisers from 10,000 tons to 8,000 tons.

The RN did have a requirement for smaller cruisers to work with the destroyer flotillas in the main fleets. However, I've decided to concentrate on larger ships for industrial reasons. For example, I think it would have been easier to build more triple 6" turrets than twin 5.25in turrets. This was partially because the former was already in production and also because the 16 Dido class ordered IOTL required 80 turrets (although not all were built) and 16 Edinburgh class needed 64 turrets.

The Old Cruisers

In the "Real World" the RN & RAN had 28 "old" cruisers at 03.09.39 consisting of Adelaide, 13 C class, 8 D class, 2 E class and 4 Hawkins class. 25 out of 28 were more than 15 years old and 19 out of 28 were more than 20 years old. As far as I know the plan was to convert the 10 newest C class to AA ships. In the end one of the 3 oldest & 7 out of the 10 newest were converted. This may have been because some of the newer ships were sunk before they could be converted. Rearming the 8 D class with 4.5in DP guns was considered, but the war stopped the programme, although Delhi was rearmed with 5 single American 5in DP guns & 2 Mk 37 FCS. One of the Hawkins class had its 7.5in guns replaced by nine single 6in guns & also had eight 4in AA guns in 4 twin mountings fitted and World War II prevented the other 3 from being modernised along similar lines. I don't remember any plans to rearm the E class in Friedman and haven't checked.

In this "Versions of History" the RN had 18 "old" cruisers at 03.09.39 consisting of 4 C class, 8 D class, 2 E class & 4 Hawkins class. 15 out of 18 were more than 15 years old and 10 out of 18 were more than 20 years old. All 4 C class and all 8 D classes had been rearmed with twin 4in AA guns. All 4 Hawkins class had been rearmed with nine single 6in guns and had also had eight 4in AA guns in 4 twin mountings fitted. Both E class had received eight 4in AA guns in 4 twin mountings by 03.09.39.

I did suggest rebuilding the Hawkins and E class along the lines of the Japanese Furukata class 1931-39 in the "Optimize the RN for WWII" thread on alternatehistory.com earlier this year as a way of preserving some infrastructure and increasing the number of modern cruisers. I'm not doing it in this thread for three reasons.
  1. Although I have more money to spend in this thread I think there isn't enough money for this and the 10 battleships that I want to lay down 1931-36. (Which can be done because there wasn't a 1930 London Naval Treaty in this "Version of History" or if the was it didn't extend the battleship building holiday from the end of 1930 to the end of 1936.
  2. There is less need to rebuild them as 64 cruisers were laid down 1924-36 in this thread compared to 52 in the other thread.
  3. Prior to 1936 the first pair of Hawkins class would become overage 1933-34, followed by the second pair in 1939-40 and the E class in 1941. Even after the age limit was increased to 20 years and the size of the cruiser force was increased to 100 ships they'd be replaced between April 1942 & March 1945 by the 12 cruisers that were to be built under the 1939-40 to 1941-42 Estimates. Therefore, they wouldn't be in service for long enough to make the rebuilds cost effective. That's also why I've rearmed the D class with 4in AA guns instead of the 4.7in DP gun which I want the RN to standardise on. The heavier guns would have been more expensive and required more extensive modifications to the ship, which would have taken more time cost more money.
Organisation of the Cruiser Force

In the "Real World" the Third Report of the D.R.C. (written in February 1936) recommended that the number of cruisers be increased from 50 (44 RN, 4 RAN & 2 NZ Div) to 70 (64 RN, 4 RAN & 2 NZ Div). It also recommended that the number of RN cruisers in full commission be increased from 30 to 44 which would allow the 7 existing cruiser squadrons to be increased from 4 ships to 5 and a second cruiser squadron (of 5 ships) to be formed in the Home Fleet.


The 14 extra cruisers would be distributed as follows:


Except, that there were 4 cruiser squadrons on the foreign stations and increasing them from 4 to 5 ships each produces a surplus of 2 ships.

In this "Versions of History" there were 70 cruisers from 1929 to 1936 including 64 in the RN (44 in full commission & 20 in refit or reserve), 4 in the RAN and 2 in the NZ Division.

The 100 cruiser force included 10 maintained by the Dominions. I don't know how many of the remaining 90 would have been in full commission, refit or reserve. My guess is that it would have been 62 in full commission and 28 in refit or reserve. About 70% of the 64 RN cruisers in the 70-ship force were to be in full commission and 62 allows or 12 squadrons of 5 ships and 2 flagships for the destroyer flotillas in the main fleets.

The 65 cruisers in the Royal Navies at the outbreak of war included 8 maintained by the Dominions. That is the RAN had 6 and the NZ Division had 2. There would also have been 8 Dominion cruisers in this "Version of History" but the RAN would have had 4 Edinburgh class instead of Adelaide & the 3 Amphions and the NZ Division would have had 2 Edinburgh class instead of 2 Leanders.

An Alternative Battle of the River Plate

Therefore, this "Version of History's" Battle of the River Plate would have been the Real-Graff Spee fighting 4 RN & NZ Division ships instead of 3 consisting of 2 County and 2 Edinburgh class ships instead of one York and 2 Leander class ships with a total of 40 guns (16 x 8in & 24 x 6in) vice 22 (6 x 8in & 16 x 6in). My guess is that Graff Spee would have been quickly overwhelmed by the British ships and sunk before she could make Montevideo. Furthermore, she would have done less damage in return to the British ships than was done in the "Real World".

Cruiser Construction by the other Naval Powers

Starting with the easy ones...

France and Italy

The size of the French and Italian cruiser (and submarine and destroyer) forces wasn't limited by the Real-1930 London Naval Treaty so I think they'd build 19 cruisers each in both "Versions of History". Neither nation had the money to build more cruisers in this "Version of History". Furthermore, a shortage of slipways prevented France from building more even if it wanted to and in fact delayed the construction of some of the ships (not just cruisers) that were built in the "Real World" so France couldn't have built more cruisers in this "Version of History" even if it wanted to.

I think that the cruisers built in the 1920s in this "Version of History" would have been built to the same designs as the "Real World" because the British only built heavy cruisers in both "Versions of History". However, both navies may have built 10,000 ton light cruisers to match the cruisers of that type the British built in place of the Leander, Amphion & Arethusa classes. Therefore, France might have built 7 & ordered 3 ships of this type instead of the Emile Bertin, La Galissonniere & De Grasse classes and Italy might have built 6 & ordered 2 ships of this type instead of the Montecuccoli, Duca D'Aosta, Abruzzi & Ciano classes.

Germany

The Reichsmarine/Kriegsmarine was screwed good and proper in this "Version of History" because before 1935 Germany was limited by the Treaty of Versailles to eight 6,000 ton light cruisers and after 1935 didn't have the industrial capacity to build more cruisers. Therefore, it would have been overwhelmed by the British Commonwealth's larger cruiser force.

The Anglo-German Naval Agreement of 1935 in both "Versions of History" allowed Germany to have 35% of the British Commonwealth's tonnage of surface warships. In 1935 that allowed Germany to have 245,000 tons of cruisers in 1935 because the British were working towards a force of seventy 10,000 ton ships for a total of 700,000 tons. This increased to an allowance of 350,000 tons when the British decided to work to a total of one hundred 10,000 ton cruisers for a total of one million tons.

Therefore, in 1935 Germany had the right to build 11 Hipper class cruisers (35% of 320,000 tons is 112,000 tons) instead of 5 and another 97,400 tons of 6in gunned cruisers (35% of 380,000 is 133,000 tons less the 35,600 tons of 6in cruisers they already had). This jumped to 112,000 tons of 8in cruisers and 238,000 tons of 6in gunned cruisers in 1936 when the British Government announced its new target of a million tons of cruisers (100 ships each displacing 10,000 tons) of which 32 would still be armed with 8in guns and 68 would be armed with 6in guns.

However, Germany didn't have the industrial capacity to build any more cruisers in this "Version of History" so they still had 8 cruisers on 03.09.39 (and were only able to complete one more) while the British Commonwealth had another 17 for a total of 82 instead of 65. Plus the total included 64 new cruisers instead of 37 and 14 of the new cruisers had heavier armaments.

Japan

Japan was free to build as many cruisers as it wanted between 1930 and 1936 in this "Version of History" provided that they displaced no more than 10,000 tons and were armed with 8in or smaller guns. However, I believe that it didn't have the money or infrastructure to build more than the 6 ships that were built under the First and Second Fleet Replenishment Programmes in the "Real World". Furthermore, Japan might not be able to build that many cruisers in this "Version of History" because it also lays down 6 capital ships 1931-36 (as was allowed by the Washington Naval Treaty) because the 1930 London Naval Treaty doesn't extend the battleship building holiday from the end of 1930 to the end of 1936 in this "Version of History". My guess is that the money saved from not rebuilding the 10 existing battleships in this "Version of History" will be enough to pay for the 6 new capital ships. However, if I'm wrong fewer submarines, cruisers and destroyers would have been built 1930-36 to provide the extra money.

However, the cruisers that were built in this "Version of History" would have been additional Takao class ships instead of the "Real World's" Mogami and Tone class cruisers. On the other hand the Japanese had to rebuild the Mogami class twice. First to strengthen their weak hulls and second when the 6in guns they were completed with were replaced with 8in guns. My guess is that the first rebuilding won't be needed because they would have had incorporated the lessons learned from the Takao class ships that were built in the "Real World" and the second rebuilding won't be necessary because they were built with 8in guns. Avoiding the two rebuilds would have given the IJN money and dockyard space that it could have used to build other ships.

The 2 Ibuki class would have been additional Takao class ships in this "Version of History" too. Japan formed its heavy cruisers into divisions of 4 ships and the plan was that they and the 2 Tone class would have formed a fifth full-strength heavy cruiser division. The IJN wanted them built under the Third Fleet Replenishment Programme of 1937 but a shortage of money and building capacity delayed this for 4 years and they were eventually ordered as part of the Rapid Naval Armaments Supplementary Programme of 1941. That's one of the reason why I think Japan could not have built more cruisers 1930-36 even if the 1930 London Naval Treaty allowed it to.

Japan also built some smaller cruisers of the Agano and Oyodo classes to work with its destroyers and submarines in the "Real World". These were built after the Japan left the Treaty System so all other things being equal there was not change to the number built. However, the RN was building more Edinburgh class instead of the Dido class in this "Version of History" and the USN may be building a Super Atlanta or more Baltimore & Cleveland class light cruisers instead of the Real-Atlanta class which were their destroyer support cruisers. Therefore, the IJN might want a "Super Agano" with nine 6in in 3 triple turrets instead of the Real-Agano with six 6in guns in 3 twin turrets or a Takao class cruiser armed with fifteen 6in guns in 5 triple turrets instead of ten 8in guns in 5 twin turrets.

The United States

The USA was free to build as many cruisers as it wanted between 1930 and 1936 in this "Version of History" provided that they displaced no more than 10,000 tons and were armed with 8in or smaller guns. Furthermore, it didn't have the financial & infrastructure restrictions that I think would have prevented Japan from building more than 6 cruisers in this "Version of History". However, Congress might not have provided the money in spite of the US Government's aspiration for naval parity with the British Commonwealth in all classes of warship and in spite of Britain completing 64 cruisers 1927-39 instead of 37 in this "Version of History". My guess is that Congress would have provided the money to lay down 10 capital ships 1931-36 (as was allowed by the Washington Naval Treaty) because the 1930 London Naval Treaty doesn't extend the battleship building holiday from the end of 1930 to the end of 1936 in this "Version of History" but it wouldn't have provided the money for more cruisers (or destroyers or submarines) and might even have provided less money for cruiser (and destroyer and submarine) construction.

This is probably a bit of wishful thinking, but the this "Version of History" version of the Cleveland class light cruisers had the Baltimore class heavy cruisers hull and machinery which allowed them to carry a fifth triple 6in gun turret. As I understand it the Cleveland class began as an 8,000 ton design (as per the terms of the Real-1936 London Naval Treaty) but grew into the 10,000 ton design that was actually built. Therefore, in this "Version of History" the class began as a 10,000 ton design (as per the terms of the Alternative-1936 London Naval Treaty) but grew into the 13,600 ton design that was actually built.

6 Cleveland class cruisers were converted into guided missile cruisers in both "Versions of History" but the ships converted in this "Version of History" had larger hulls which allowed more guns to be retained or a second Terrier or Talos launcher to be fitted. The resulting ships might have resembled Boston and Canberra, except that they had three triple 6in turrets forward instead of two triple 6in turrets forward. Unfortunately, in both "Versions of History", the cost of the Vietnam War prevented them from having another refit in the late 1960s in which new radars & electronics would have fitted and their guided missile systems would have been modernised.

The 9 Independence class light fleet carriers of this "Version of History" were more capable ships because they were effectively converted Baltimore class heavy cruisers instead of converted Cleveland class light cruisers and therefore had longer & beamier hulls. This might not have made much difference in World War II, but it would have made them more useful after the war, especially for the French Navy which received 2 in the 1950s and the Spanish Navy which received one in the 1960s.

There might not have been an Atlanta class anti-aircraft cruiser in this "Version of History" or at least they might have been built to a different design. The Real-Atlanta class (in common with the British Dido class and Japanese Agano class) was designed to work with the destroyer flotillas (hence the small size and large number of rapid fire guns) and replace the Omaha class light cruisers currently used in that role. However, with the RN building more Edinburghs instead of the Didos and the IJN possibly building a larger & more powerful version of the Agano class or versions of the Takao class armed with fifteen 6in guns the USN may have decided that a larger and more heavily armed version of Atlanta was needed or they should build more Cleveland class cruisers instead.

The End of Cruisers
But NOMISYURRUC will return with Destroyers

Which hopefully will take a lot less time to write
And not be six pages of A4 long in twelve part Times New Roman.​
Click to expand...
Thank you so much for your help!
 
Destroyers​

Introduction

In the "Real World" the British Commonwealth had 192 destroyers on 03.09.39 plus 24 under construction. However, in this "Version of History" the British Commonwealth had 266 destroyers on that date plus 48 under construction.

Two things made this possible. Firstly there was no Geddes Axe and British Government taxation & spending were maintained at 1921-22 levels from 1922-23 to the middle 1930s. Secondly, there was no First London Naval Treaty or a less restrictive Treaty which didn't have tonnage quotas for destroyers (or submarines or cruisers).

The 192 destroyers on 03.09.39 in the "Real World" were nearly enough to form 22 flotillas of 8 or 9 boats and the 266 destroyers on 03.09.39 in my "Version of History" were enough to form 30 flotillas of 8 or 9 boats. In the "Real World" one-and-a-half flotillas were manned by the Dominion Navies (½ RAN and one RCN). In my "Version of History" 3 flotillas were manned by the Dominions (one RAN & 2 RCN).

This section doesn't include the Hunt class escort destroyers because I'm counting them as minor war vessels.

Destroyer Requirements

The requirement in 1924 was for 15 flotillas, which increased to 16 by 1929 (of which 12 were to work with the fleet & 4 were for local defence) and 22 flotillas in the middle 1930s (of which 16 were to work with the fleet & 6 were for local defence). The fleet destroyers had to be under age and the local defence ships could be overage. It's much simpler in my "Version of History" as the requirement was for 30 flotillas of which 6 could be overage from 1924 to 1939.

In 1924 a destroyer became overage 12 years after its date of completion. The First London Naval Treaty increased that to 16 years for a ship laid down after 31.12.20 but left it at 12 years for a ship laid down before 01.01.21. There wasn't a First London Naval Treaty in my "Version of History" so a destroyer continued to become overage 12 years after its date of completion regardless of when it was laid down. Therefore, a building rate of 2 flotillas a year was required to maintain a force of 30 flotillas including 6 that were overage.

Destroyer Construction 1924-39

The 10-Year Plan of 1924 included the construction of 135 destroyers (15 flotillas).
  • 2 flotillas a year under the 5 Navy Estimates 1926-27 to 1930-31.
  • 1 flotilla a year in the 5 Estimates 1931-32 to 1935-36.
  • Plus 2 prototypes to be built under the 1924-25 Estimates.
85 destroyers (9½ flotillas) were built, plus the pair of prototypes and 2 ships built for Canada, for a total of 89.
  • 2 Experimental A class as planned under the 1924-25 Estimates.
  • 1 flotilla of A-to-I class a year in the 9 Estimates 1927-28 to 1935-36.
    • Except for the 1929-30 Estimates when half-a-flotilla of C class destroyers (5 ships) was ordered.
    • This was as a gesture of goodwill before the First London Naval Conference.
  • 1 flotilla of Tribal class (7 ships) in the 1935-36 Estimates.
  • 2 A class were built for the RCN.
The plan in 1936 was to build 8 flotillas (64 ships) in the 4 Estimates 1936-37 to 1939-40 at the rate of 2 flotillas a year. What was actually built was.
  • 1 flotilla of Tribal class (9 ships) under the 1936-37 Estimates.
  • 1 flotilla of Javelin class (8 ships) under the 1936-37 Estimates.
  • 1 flotilla of Javelin class (8 ships) in the 1937-38 Estimates.
  • 1 flotilla of Lightning class (8 ships) in the 1937-38 Estimates.
  • No destroyers were built under the 1938-39 Estimates. The 2 flotillas (16 ships) planned weren't built due to the "rationing" of the Rearmament Programme due to the economic problems that it was creating.
  • 1 flotilla of Javelin class (8 ships) in the 1939-40 Estimates.
  • 1 flotilla of Lightning class (8 ships) in the 1939-40 Estimates.
The grand total was 137 built under the 1924-25 to 1939-40 Estimates of which 113 were completed before 03.09.39 and 24 were under construction.

250 destroyers were built under the 1924-25 to 1939-40 Estimates in this "Version of History" of which 202 had been completed by 03.09.39 and 48 were under construction.
  • 4 Experimental A class under the 1924-25 Estimates.
  • 18 flotillas of A-to-I class (162 ships) under the 1926-27 to 1934-35 Estimates.
  • 10 flotillas of Javelin class (80 ships) under the 1935-36 to 1939-40 Estimates.
  • 4 A class were built for the RCN.
Thanks to the extra building capacity that was maintained 1922-36 in my "Version of History" it was possible to complete the 48 destroyers that were under construction at 03.09.39 faster than the 24 that were under construction at 03.09.39 in the "Real World". That is 16 were completed between September 1939 & March 1940, 16 were completed between April 1940 & March 1941 and the last 16 were completed between April 1941 & March 1942. That was a considerable improvement on the 24 "Real World" ships because the first 6 were completed between November 1940 & February 1941, the next 10 were completed between May 1941 & February 1942 and the last 8 were completed between May 1942 and April 1943. This meant that 48 destroyers were completed to March 1942 in this "Version of History" and only 16 were completed to March 1942 in the "Real World".

What Type of Destroyer?

The ALT-A-I classes were enlarged versions of the Real-A-to-I classes with longitudinally framed hulls. The hulls were larger because they had to take the extra top weight of the four or five 4.7in guns in single DP mountings and their DP tachometric director. The larger hull also meant that the destroyers could be fitted with radar, more light AA guns, new AS weapons and improved asdic more easily.

The ALT-Javelin class was an enlarged version of the Real-Javelin class because (in common with the A-to-I classes) to take the extra weight of the six 4.7in guns in twin DP mountings and their DP tachometric radar. Also in common with their predecessors the larger hull meant the class could be fitted with radar, more light AA guns, new AS weapons and improved asdic more easily.

There was no Tribal class in this "Version of History" because the RN had all the cruisers that it wanted so there was no need for a class of scout destroyers to supplement them. The Lightning class was built (in common with the Tribal class) to compensate for the shortage of cruisers by giving them more powerful guns than the Javelin class, but in this "Version of History" there was no need for the more powerful guns because the RN had more cruisers so no Lightning class.

The Old Destroyers

The 79 old destroyers at 03.09.039 in the "Real World" consisted of 8 Leaders, 59 V&W class and 12 R&S class ships. One Leader & 10 V&W classes had been converted to escort destroyers. Their existing armament (including the torpedo tubes) was removed and replaced by two or three twin 4in AA guns. Another 5 V&W class were converted to escort destroyer during the war.

In my "Version of History" there were 64 old destroyers (7 flotillas) which consisted of 8 Leaders and 56 V&W class. (The eighth leader formed a flotilla with the 4 Experimental A class & the 4 RCN A class.) None of them had been converted to escort destroyers because they were scheduled to be scrapped by March 1943 so the cost of the conversion was not considered to be worth it due to the limited remaining service life of the ships. However, one or two older flotillas of the A-to-I class might have been converted to escort destroyers in their place. The larger hulls may have allowed an extra twin 4in AA mounting to be fitted.

Destroyer Construction by the other Naval Powers

Starting with the easy ones...

France and Italy

The size of the French and Italian destroyer (and submarine and cruiser) forces wasn't limited by the Real-1930 London Naval Treaty so I think they'd build the same number of ships in both "Versions of History". Neither nation had the money to build more destroyers in this "Version of History". Furthermore, a shortage of slipways delayed the construction of some of the ships (not just destroyers) that France built in the "Real World" so France couldn't have built more destroyers in this "Version of History" even if it was richer.

With one exception I don't see the qualitative improvements in the RN's destroyers leading to France and Italy building better destroyers in this "Version of History". The exception is that not having the First London Naval Treaty may lead to them building the La Melpomène and Spica classes of torpedo boats to a larger design. E.g. France might build 12 ships of the Le Fier type in their place.

Germany

The real Reichsmarine/Kriegsmarine was limited to 16 destroyers of 800 tons by the Treaty of Versailles and from 1935 to 35% of the British Commonwealth's destroyer strength under the Anglo-German Naval Agreement in both "Versions of History". However, in my "Version of History" the British Commonwealth had considerably more destroyers, which Germany couldn't exploit because it didn't have the industrial capacity to build the extra ships and spent too much time making its mind up on the types of destroyers it wanted. Therefore, it still had 22 large & 12 small destroyers on 03.09.39 and would complete another 18 large & 36 small destroyers during the war. I think there wouldn't be any qualitative improvements to the ships.

Japan

Japan was free to build as many destroyers as it wanted between 1930 and 1936 in this "Version of History". However, I believe that it didn't have the money or infrastructure to build more than the 26 ships that were built under the First and Second Fleet Replenishment Programmes in the "Real World". Furthermore, Japan might not be able to build that many destroyers in this "Version of History" because it also lays down 6 capital ships 1931-36 (as was allowed by the Washington Naval Treaty) because the 1930 London Naval Treaty doesn't extend the battleship building holiday from the end of 1930 to the end of 1936 in this "Version of History". My guess is that the money saved from not rebuilding the 10 existing battleships in this "Version of History" will be enough to pay for the 6 new capital ships. However, if I'm wrong fewer submarines, cruisers and destroyers would have been built 1930-36 to provide the extra money.

On the other hand Japan would have been able to build 26 Asashio class destroyers instead of the 6 Hatsuharu cass, 10 Shiratsuyu class and 10 Asashio class built in the "Real World" because it didn't have to build the unsatisfactory ships of the first two classes because there wasn't a destroyer tonnage quota in my "Version of History". No tonnage quota in my "Version of History" also allowed Japan to build 20 second class destroyers of the Matsu type in place of the 12 torpedo boats (of 20 planned) that were built under the First and Second Fleet Replenishment Programmes.

The United States

In the "Real World" the USN had 171 destroyers on 07.12.41. This consisted of 72 old and 99 new destroyers. It wouldn't necessarily have any more destroyers on that date in this "Version of History". Although the USA's aspiration was to have a navy that was second to none Congress didn't provide the money to do that in the "Real World" and the same would apply in this "Version of History". In a way it might have been worse here because in the "Real World" the USN had a legal entitlement to 150,000 tons of underage destroyers and it was able to get the Vinson-Trammel act passed in 1934 which forced Congress to provide the money necessary to reach that target.

Not having a First London Naval Treaty or a less restrictive one in my "Version of History" means that 32 flush deck destroyers don't have to be scrapped to stay within the Treaty's tonnage quota (because there was no tonnage quota) but the 61 ships with Yarrow boilers would still have been scrapped. However, the 32 extra ships may have been added to the 46 serving in subsidiary roles on 07.12.41 or the 50 transferred to Great Britain in the "Real World".

The RN laid down the A class destroyers in 1928 in the "Real World" but the USN didn't lay down the Farragut class until 1932. In my "Version of History" the RN laid down the A class destroyers in 1927 and the USN still laid the Farragut class down in 1932. It also ordered 250 destroyers 1924-39 (including the Experimental A class and the RCN A class) instead of 137 and I think that wouldn't spur Congress into increasing the number of destroyers funded over the same period either.

What would spur Congress is to funding more destroyers is Japan building more destroyers. As already related Japan may build 20 second class destroyers instead of the 12 (of 20 planned) torpedo boats, but other than that I think Japan couldn't afford to build any more than that. The construction of the 20 second class destroyers might push Congress into funding 20 destroyer escorts in the 1930s, but they didn't build 12 torpedo boats to match the 12 that Japan built in "Real World" and therefore the 20 small destroyers built in their place in "Version of History" doesn't automatically mean Congress would fund 20 ships to counter them.

However, not having a destroyer tonnage quota would allow the USA to build the same number of destroyers to a larger design and Congress may be persuaded to pay the extra cost. Therefore, the Farragut to Benson/Gleaves classes may have been built to proto-Fletcher designs. The Porter & Somers classes of flotilla leader were built to exploit the clause of the Treaty that allowed 16% of the USA's 150,000 tons to have a displacement of 1,850 tons instead of 1,500 tons. The USN didn't build specialised flotilla leaders afterwards which suggests that the Fletcher and later classes were large enough to perform the task and therefore didn't need to build flotilla leaders. If that's the case more proto-Fletchers would have been built instead of the Porter and Somers classes. However, if they weren't then classes of Super Porter and Super Somers class flotilla leaders would have been built in place of the real ships of those classes. They would have had hulls large enough to take eight 5in guns in four twin DP mountings (the real ships had LA mountings) and ten 21in TT in two quintuple mountings (instead of eight 21in TT in two quadruple mountings).

The End of Destroyers
But NOMISYRRUC will return with Minor War Vessels

This part was four pages of A4 long in twelve part Times New Roman.​
 
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Minor War Vessels​

Introduction

These include sloops, frigates, corvettes, large minesweepers and escort destroyers. That's why the latter weren't included in the destroyers section.

All the minor war vessels built to 1939 were classified as sloops and this is a quote from Page 172 of "Warships of World War II" by H.T. Lenton & J.J. Colledge.
Thus, by 1939, sloops fell into three broad classes as below:-
(a) Escort - capable of ocean A/S and A.A. duties.​
(b) Patrol - capable of coastal A/S duties.​
(c) Minesweeping - capable of ocean and coastal M/S duties and could be pressed into performing either (a) or (b) if so required.​
Click to expand...
There were 98 sloops of all types (including 3 RAN & 6 RIN) in service in September 1939.
40 Escort Sloops​
8 Flower, "24", Lawrence and Clive classes launched 1915-19 including one RAN and 3 RIN​
15 Bridgewater, Hastings, Shoreham and Falmouth classes launched 1928-32 including one RIN​
11 Grimsby class launched 1933-36 including 2 RAN and one RIN.​
3 Bittern class launched 1934-37.​
3 Egret class launched 1938.​
11 Patrol Sloops.​
2 PC class launched 1918 including one RIN.​
9 Kingfisher class launched 1935-39.​
47 Minesweeping Sloops.​
26 Hunt class launched 1917-19.​
21 Halcyon class launched 1933-39.​

104 minor war vessels were under construction or on order when war was declared.
20 Hunt class escort destroyers.​
8 escort sloops.​
2 Grimsby class for the RAN.​
4 Black Swan class for the RN.​
2 Black Swan class for the RIN.​
56 Flower class corvettes for the RN.​
20 Bangor class minesweeping sloops for the RN.​

In my "Version of History" the number in service was increased from 98 to 124 and the number under construction and on order was increased from 104 to 208.

Minor War Vessel Requirements

In 1929 the Admiralty wanted to continue building them at the then current rate of 8 a year. I don't know what the service life for minor war vessels was at the time, but I do know that it was 12 years for destroyers and 8 a year for 12 years produces a force of 96 underage ships. In the middle 1930s there was a requirement for 120 in the One-Power Standard Fleet and 226 in the Two-Power Standard Fleet. The requirement had risen to 300 by April 1939 and not long afterwards there was a requirement for 100 additional ships of a type that would become the River class frigates.

Minor War Vessel Construction

In the "Real World" 60 were ordered for the RN in the 11 financial years 1927-28 to 1937-38, none were ordered in 1938-39 and 98 were ordered in the 5 months between April 1939 & the declaration of war for a total of 158. Furthermore, 4 were ordered from British yards by the RIN and 4 were ordered from Australian yards for the RAN. The grand total ordered by the British Empire & Commonwealth was 166.

In my "Version of History" 120 were ordered in the 11 financial years 1927-28 to 1937-38 and 200 were ordered in the 17 months between April 1938 & the declaration of war for a total of 320. The number of vessels built for the RIN was doubled from 4 to 8. However, the number of RAN vessels was unchanged. That increased the grand total ordered by the British Empire & Commonwealth between 1927 and September 1939 from 166 to 332.

There were no legal restrictions on building minor war vessels in these numbers because the Real First London Naval Treaty allowed them to be built in unlimited numbers on the conditions that they displaced less than 2,000 tons, had a maximum speed of less than 20 knots, weren't armed with torpedoes and carried a maximum of four 6in guns. Furthermore, there wasn't a less restrictive First London Naval Treaty or none at all in my "Version of History".

What type of Minor War Vessel 1927-37?

The ships ordered 1927-37 in the "Real World" were fit for purpose. The problem was that there weren't enough of them. Therefore, with one exception each class was built in double the numbers of the "Real World". The exception was that 60 Halcyon class minesweeping sloops were built instead of 18 Kingfisher class patrol sloops and 42 Halcyons.

The Real-Jane's 1939 said that the 22 RN escort sloops of the Bridgewater to Grimsby classes were to be rearmed with six 4in AA guns in three twin mountings. The ALT-Jane's 1939 said that the 44 RN escort sloops of the Bridgewater to Grimsby classes were being rearmed with six 4in AA guns in three twin mountings. This was in part because no fleet destroyers were being converted to escort destroyers in my "Version of History" so the guns and fire control equipment fitted to them in the "Real World" was fitted to some of the sloops in this "Version of History".

Doubling of sloop construction between 1927 and 1937 didn't mean that the number in service at the declaration of war was increased from 98 to 160. Instead it was increased from 98 to 124. The number of RN vessels was increased from 89 to 151 and the number of RAN & RIN vessels was the same at 3 and 6 respectively.

What Type of Minor War Vessel 1937-39?
Escort Destroyers

The first 20 Hunt class destroyers were ordered in the 1939-40 Estimates in the "Real World" and 40 were ordered in the 1938-39 & 1939-40 Estimates in my "Version of History". Unlike 84 of the 86 ships of the Hunt type built in the "Real World" all the Hunts built in this "Version of History" carried an armament of six 4in AA guns in three twin mountings and three 21in torpedo tubes in a triple mounting. Furthermore, they all had a maximum speed of 30 knots.

Escort Sloops and Patrol Sloops

The designs built 1927-37 were fit for purpose, but they could only be built in yards with warship building experience so the hulls couldn't be built in the numbers required in wartime. Furthermore, there wasn't enough capacity to build their geared-turbine machinery in the numbers required in wartime.

The "Real World" solution was to build as many Black Swan class escort sloops as possible and supplement them with large numbers of Flower & Castle class corvettes and River & Loch/Bay class frigates which could be built in yards that had no warship building experience. The Flower class was an enlarged commercial whaler and in turn the Castle class was an enlarged Flower class. According to Friedman (who else) the River class was a version of the Black Swan class that could be built by yards that had no warship building experience.

The Loch/Bay was a redesigned version of the River class and was optimised for mass production on dispersed sites. This is a quote from Page 22 of "Royal Navy Frigates 1945-1983" by Leo Marriott.
To facilitate this, the ship was built of prefabricated sections which could be constructed at dispersed sites and moved by road or rail to an assembly slipway. Each section had maximum dimensions of: length 29ft; width 8ft 6in; and height 8ft in. Maximum weight of each section was set at 2½ tons to suite crane capacity at the shipyards. Eighty per cent of the hull and superstructure was made of prefabricated units, the rest of the structure was worked in by the assembly yard. The setting up of the organisation necessary to run a widely dispersed production system was a massive task, and took some time. However, once in operation, the time required to complete a frigate was drastically reduced. Whereas the average time take to complete a conventionally constructed "River" class frigate was in the order of 15 to 18 months, a prefabricated "Loch" class frigate was completed in an average time of 10 to 11 months. Had the war continued past 1945, building times would probably have fallen even more as the tempo of production increased.
Click to expand...
In this "Unreal World" more shipyards had warship building experience because more warships were built between the mid-1920s and the mid-1930s. This included double the number of destroyers and double the number of minor war vessels. The capacity to build geared turbines was greater too. Therefore, Britain was able to build at least twice as many Black Swan class frigates. The number building or under construction at the declaration of war in the "Real World" was 6 made up of 2 RN in the 1937-38 Estimates, 2 for the RN in the 1939-40 Estimates and 2 for the RIN. In my "Version of History" it was 16 made up of 4 for the RN in each of the 3 Navy Estimates for 1937-38, 1938-39 & 1939-40 and 4 for the RN.

However, this still wasn't enough and a design that could be built in yards that hand no warship building experience was still required. The solution in my "Version of History" was to "cut out of the middlemen" and build frigates based on the Black Swan class from the start. Therefore, 112 Bay class were ordered under the 1938-39 and 1939-40 Estimates. In common with what Marriott wrote the setting up of the organisation necessary to run a widely dispersed production system was a massive task, and took some time. Therefore, the first ships weren't completed until well after the declaration of war in spite of being ordered in the spring of 1938. However, as he also wrote once in operation the time taken to complete a frigate was drastically reduced. Furthermore, a greater proportion of the ships built in place of the "Real World's" corvettes and frigates could be built with geared turbines because the capacity to build them was greater in this "Version of History".

Minesweeping Sloops

Again the Halcyon class was an excellent design that the Admiralty thought couldn't be built in the required numbers in wartime. The result was the Bangor class, which were diminutives of the Halcyon class and equally efficient. The first 20 were built under the 1939-40 Estimates. Unfortunately, later war requirements to counter influence (and magnetic & acoustic) mines resulted in them being cramped for space and their construction was discontinued in favour of the Algerine class which reverted to the larger dimensions of the Halcyon class.

In my "Version of History" more Halcyon or more Algerine class minesweeping sloops were built instead of the Bangor class. 40 were built to pre-war programmes, but the number of hulls built during the war was the same as the number built in the "Real World". However, a larger percentage was built with geared turbines instead of reciprocating engine or diesels because the capacity to build them was greater in this "Version of History".

Minor War Vessel Construction by Other Countries

Unlike the other types of warships so far discussed the extra minor war vessel production by the British Commonwealth between the wars had no effect on the number or design of vessels of this type built by other nations.

The End of Minor War Vessels
But NOMISYRRUC will return with Capital Ships​
 
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NOMISYRRUC said:
Submarines
Part4 – What were the other naval powers doing?​
Click to expand...
You seems to forgot the USSR, which actually was the largest submarine-builder in 1930s. And in cruisers and destroyers, too. While USSR wasn't directly involved into treaties system, it actually observed very carefully other nations development and made a conclusions out of it.
 
Destroyers and Minor War Vessels Ordered for the Royal Navy only 1924-39.
They don't include ships ordered for the Dominion Navies and India.
They don't include ships ordered under the War Emergency Programme.

"The Real World"

DD & FF 1919-39 Real World.png

"My Version of History"

DD & FF 1919-39 Unreal World.png

The Difference

DD & FF 1919-39 Difference.png ​
 
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