More Light and No Heavy Cruisers - Revised
I had forgotten that Nürnberg was intended to be an 8,000 ton version of Leipzig, rather than a repeat of the Leipzig design. This is what the Germans actually wanted to do, because the larger hull would have given better hull strength, allowed for superior protection for the turrets and magazines, permitted a heavier flak armament and an increase in speed. However, the designers spent the years 1933-35 on what would become the Hipper class and as a result Cruiser F had to be a repeat of Leipzig because no other design was available.
As the Germans weren't designing what became the Hipper class ITTL it would be possible to design the enlarged Leipzig in time to build Cruiser F (Nürnberg) to this design. Therefore the 6 light cruisers built in place of the 5 Hippers would be "Super Leipzigs" rather than what I suggested before, which was to bring the Cruiser M design forward 4 years.
The Hipper class were intended to take 36 months to build, but the 3 ships that were completed took an average of 48 months to build. The Cruiser M class were planned to take 30 months to build at the time they were ordered and I was going to have the 6 Cruiser M class laid down instead of the 5 Hippers and Graff Zeppelin built in an average of 42 months. However, the real Nürnberg was build in 24 months, albeit before the Germans began their expansion programme. Therefore the projected building times for the 6 "Super Leipzigs) that I now propose to be laid down in place of the 5 Hippers and Graff Zeppelin to have a projected building time of 24 months but because of the overloading of the shipyards to complete them in an average of 36 months.
On that basis:
Rostock (Cruiser G - Blucher IOTL) laid down 15/08/1935 and completed on 20/09/1938 instead of 20/09/1939;
Elbing (Cruiser H - Hipper IOTL) laid down 06/07/1935 and completed on 29/04/1938 instead of 29/04/1939;
Wiesbaden (Cruiser J - Prinz Eugen IOTL) laid down 23/04/1936 and completed 01/08/1939 instead of 01/08/1940;
Mainz (Cruiser K - Seydlitz IOTL) laid down 29/12/1936 and completed 01/01/1940 instead of never;
Frankfurt (Cruiser L - Lützow IOTL) laid down 02/08/1937 and completed 01/08/1940 instead of never;
Dresden (Cruiser M - built in stead of Graff Zeppelin IOTL) laid down 28/12/1936 and completed 31/12/1939 instead of never.
One of the reasons behind the change from Cruiser M to Super Leipzig is what Saphroneth said about the shortage of gun pits. Although he was referring to 15" turrets for the 2 extra Bismarcks the same presumably applied to cruiser turrets and it would be easier to build 18 triple 6" than 24 twin 6".
If the Germans can get these ships out the shipyards about a year earlier, that reduces the congestion in the shipyards and increases the capacity to complete the other ships that were under construction or planned.
The 1930 London Naval Treaty allowed the British Empire 339,000 tons of cruisers and on that basis the Anglo-German Naval Agreement gave Germany an allowance of 118,650 tons. ITTL the Emden, Koln class, Leipzig and the 7 Super Leipzigs absorb 86,000 tons, which leaves 32,000 tons. Therefore the Germans would be within their rights to build another 4 Super Leipzigs. Therefore Cruisers N, O, P and Q are ordered in the middle of 1936 (which is the same time as J and K were ordered IOTL) and when the British announce their plan to expand their fleet from 50 to 70 cruisers it gives Germany the right to order Cruisers R and S in the first half of 1937. In 1936-37 it was planned that the first sextet of Super Leipzigs would be completed between July 1937 and July 1939 with the second 6 to be laid down after G to M were launched and completed between July 1939 and the end of 1940. As already explained the first 6 were completed between April 1939 and August 1940 so the second sextet was put back to from July 1940 to the end of 1941.
IOTL the Germans had planned to rebuild theKöln class, Leipzig and Nürnberg after the faults in their design had been revealed during the Spanish Civil War, but only the Karlsure had been rebuilt before war broke out. ITTL as the Germans are planning for the strongest possible fleet by 1939 they would assign greater priority to the rebuilds, even if it meant delaying new ships and they also have the advantage that only 4 ships need to be rebuilt instead of 5.
I had forgotten that Nürnberg was intended to be an 8,000 ton version of Leipzig, rather than a repeat of the Leipzig design. This is what the Germans actually wanted to do, because the larger hull would have given better hull strength, allowed for superior protection for the turrets and magazines, permitted a heavier flak armament and an increase in speed. However, the designers spent the years 1933-35 on what would become the Hipper class and as a result Cruiser F had to be a repeat of Leipzig because no other design was available.
As the Germans weren't designing what became the Hipper class ITTL it would be possible to design the enlarged Leipzig in time to build Cruiser F (Nürnberg) to this design. Therefore the 6 light cruisers built in place of the 5 Hippers would be "Super Leipzigs" rather than what I suggested before, which was to bring the Cruiser M design forward 4 years.
The Hipper class were intended to take 36 months to build, but the 3 ships that were completed took an average of 48 months to build. The Cruiser M class were planned to take 30 months to build at the time they were ordered and I was going to have the 6 Cruiser M class laid down instead of the 5 Hippers and Graff Zeppelin built in an average of 42 months. However, the real Nürnberg was build in 24 months, albeit before the Germans began their expansion programme. Therefore the projected building times for the 6 "Super Leipzigs) that I now propose to be laid down in place of the 5 Hippers and Graff Zeppelin to have a projected building time of 24 months but because of the overloading of the shipyards to complete them in an average of 36 months.
On that basis:
Rostock (Cruiser G - Blucher IOTL) laid down 15/08/1935 and completed on 20/09/1938 instead of 20/09/1939;
Elbing (Cruiser H - Hipper IOTL) laid down 06/07/1935 and completed on 29/04/1938 instead of 29/04/1939;
Wiesbaden (Cruiser J - Prinz Eugen IOTL) laid down 23/04/1936 and completed 01/08/1939 instead of 01/08/1940;
Mainz (Cruiser K - Seydlitz IOTL) laid down 29/12/1936 and completed 01/01/1940 instead of never;
Frankfurt (Cruiser L - Lützow IOTL) laid down 02/08/1937 and completed 01/08/1940 instead of never;
Dresden (Cruiser M - built in stead of Graff Zeppelin IOTL) laid down 28/12/1936 and completed 31/12/1939 instead of never.
One of the reasons behind the change from Cruiser M to Super Leipzig is what Saphroneth said about the shortage of gun pits. Although he was referring to 15" turrets for the 2 extra Bismarcks the same presumably applied to cruiser turrets and it would be easier to build 18 triple 6" than 24 twin 6".
If the Germans can get these ships out the shipyards about a year earlier, that reduces the congestion in the shipyards and increases the capacity to complete the other ships that were under construction or planned.
The 1930 London Naval Treaty allowed the British Empire 339,000 tons of cruisers and on that basis the Anglo-German Naval Agreement gave Germany an allowance of 118,650 tons. ITTL the Emden, Koln class, Leipzig and the 7 Super Leipzigs absorb 86,000 tons, which leaves 32,000 tons. Therefore the Germans would be within their rights to build another 4 Super Leipzigs. Therefore Cruisers N, O, P and Q are ordered in the middle of 1936 (which is the same time as J and K were ordered IOTL) and when the British announce their plan to expand their fleet from 50 to 70 cruisers it gives Germany the right to order Cruisers R and S in the first half of 1937. In 1936-37 it was planned that the first sextet of Super Leipzigs would be completed between July 1937 and July 1939 with the second 6 to be laid down after G to M were launched and completed between July 1939 and the end of 1940. As already explained the first 6 were completed between April 1939 and August 1940 so the second sextet was put back to from July 1940 to the end of 1941.
IOTL the Germans had planned to rebuild theKöln class, Leipzig and Nürnberg after the faults in their design had been revealed during the Spanish Civil War, but only the Karlsure had been rebuilt before war broke out. ITTL as the Germans are planning for the strongest possible fleet by 1939 they would assign greater priority to the rebuilds, even if it meant delaying new ships and they also have the advantage that only 4 ships need to be rebuilt instead of 5.