Link to Post 124 which is what I think Germany should have built 1919 to c. 1932.
What I think the Kriegsmarine's Destroyer Policy should have been.
The Destroyers the Kriegsmarine built 1933-45 IOTL.
It is a continuation of Post 124, which is what I think the Reichsmarine's Building Policy should have been.
From June 1935 to April 1939 the size of the Kriegsmarine's Destroyer Force was a function of the size of the British Commonwealth's Destroyer Force. Initially, it was 52,500 tons which was 35% of the British Commonwealth's First London Naval Treaty Destroyer Quota of 150,000 tons. However, the British Commonwealth had 204,809 tons when that Treaty expired which meant that Germany could have 71,683 tons of Destroyers under the A.G.N.A., and at the outbreak of World War II it had grown to 256,752 tons which if the Agreement had still been in force would have given Germany the legal right to 89,683 tons of Destroyers. The growth in the size of the British Commonwealth's Destroyer Force and the permitted size of the German Destroyer Force is illustrated by the following table.
The Kriegsmarine had 9,600 tons of Destroyers at 18.06.35 (the 12 Small Destroyers of the 800-ton type built by the Weimar Republic) so the amount of tonnage available for new construction was:
- At 18.06.35 - 42,900 tons
- At 31.12.36 - 62,083 tons and 22 Z-Boats with an official displacement of 36,866 tons were ordered by that date.
- At 03.09.39 - 80,263 tons and 42 Z-Boats with an official displacement of 73,086 tons were ordered by that date.
Therefore, Germany wouldn't have been in breach of the A.G.N.A. on 03.09.39 if it had still been in force.
- The 42 Z-Boats ordered to 03.09.39 consisted of 4 Type 1934, 12 Type 1934A, 6 Type 1936, 8 Type 1936A and 12 Type 1938B.
- The 12 Type 1938B (Z31-Z42) were ordered in the Summer of 1939 and re-ordered as Type 1936A Z-Boats on 19.09.39, of which:
- 7 (Z31 - Z34 & Z-37-39) were built the Type 1936A design;
- 2 (Z35 & Z36) were built to the Type 1936B design and;
- 3 (Z40 - Z42) were re-ordered as Spähkreuzer 1 - 3, but none were completed.
- Therefore, only 39 of the 42 Z-Boats ordered to 03.09.39 were built.
- Another 14 Z-Boats (Z43 - Z56) were ordered during the war:
- 3 Type 1936B (Z43 - Z45);
- 5 Type 1936C (Z46 - Z50);
- 1 Type 1942 (Z51) and;
- 5 Type 1944 (Z52 - Z56);
- Z43 was the only ship out of the 14 ordered to be completed.
- At total of 40 large destroyers of the Z-Type was completed.
The faults of the Type 1934 and 1934A designs were cured in the Type 1936 design, but unfortunately (for the Kreigsmarine) 5 out of 6 were lost in the Narvik battles. This included reliable machinery because according to (Whitley who I got the above information from) the sole surviving Type 1936 destroyer (Z20 Karl Glaster) had a good reputation including a good serviceability record. According to him the Type 1936 Z-boats also had a marginally greater range than the Type 1934 and their machinery was more economical than the subsequent Type 1936A because their engines were modified at the insistence of OKM.
Then the Kriegsmarine went "back to square one"
with the Type 1936A, which was the Type 1936 hull & machinery mounting five 5.9in guns instead of the five 5in guns that had armed Types 1934, 1934A & 1936. The Type 1936B returned to an armament of five 5in guns but unfortunately (for the Kriegsmarine) only 3 out of the 5 boats could be completed. The Type 1936C was the Type 1936A hull & machinery with a main armament of six 5in guns in three twin DP mountings. Types 1942 & 1944 were new designs with diesel engines in place of the previous high-pressure steam machinery.
10 F-Boats & 12 T-Boats with an official displacement of 13,200 tons were also ordered to the end of 1936 which was increased to 10 F-Boats and 30 T-Boats with an official displacement of 24,000 tons by 03.09.39. These ships were built to exploit the section of the First London Naval Treaty that allowed unlimited construction of surface torpedo-craft displacing less than 600 tons. Therefore, they weren't counted as part of Germany's Destroyer tonnage. If they had Germany would have exceeded its A.G.N.A. allowance on 31.12.36 and (if it had still been in force) on 03.09.39 too.
Another 39 T-Boats were ordered during the war, which increased the total to 69, as follows:
- 12 Type 1935 (T1 - T12);
- 9 Type 1937 (T13 - T21) - 18 (T13 - T30) were ordered but the last 9 were built to the much better Type 1939 design;
- 15 Type 1939 (T22 - T36);
- 15 Type 1941 (T37-T51);
- 6 Type 1944 (T52-T57);
- 12 Type 1940 (T61-T72) which were ordered from Dutch yards.
However, only 36 (T1 - T36) were completed.
The Type 1935 & 1937 T-Boats (along with the Type 1934 F-Boat) were rubbish. They were so bad that Whitley (in his German Destroyers of World War II book) spends several paragraphs discussing whether they were a waste resources. It was fortunate (for the Kriegsmaine) that T31 - T36 were built to a different design because the Type 1939 T-Boats were Germany's best destroyers.