Zenker’s Cruiser Killer - German Battlecruiser design (1928)
Oct 22, 2021 9:53:15 GMT
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Post by lordroel on Oct 22, 2021 9:53:15 GMT
Zenker’s Cruiser Killer - German Battlecruiser design (1928)
The Weimar Republic, that forward-looking liberal outgrowth of the collapsed German Empire, was not a peace-loving entity. Well before the rise of Adolf Hitler, the republic planted the seeds of military revival.
The Versailles Treaty and its addenda destroyed German naval power — with serious help from the Germans themselves. On 21 November 1918, as part of the Armistice provisions, the bulk of the German High Seas Fleet sailed to Scapa Flow for internment. In May 1919, the Allies informed the German delegates at Versailles that all of the ships at Scapa Flow would have to be turned over to the Allies, with most going to Britain. Rear Admiral Ludwig von Reuter reacted by ordering the fleet to scuttle itself, and on 17 June 1919 twelve battleships, five battle cruisers, eight light cruisers and fifty destroyers went to the bottom of the anchorage.
The gesture did little for Germany: The angry Allies made the Germans hand over all their remaining modern warships, and billed them for the scuttled fleet.
When the Weimar Republic’s new Reichsmarine was founded on 31 March 1921, its leaders foresaw Germany going to war against an alliance of France and Poland. Britain and the United States, they believed, would stay neutral in such a conflict. British Prime Minister David Lloyd George’s behavior during the Russo-Polish War of 1921 seemed to confirm this belief, as Britain remained aloof while Poland was nearly overrun by the Red Army.
Vice-Admiral Hans Zenker, the Reichsmarine’s commander from 1924 to 1928, prepared the navy’s building program around this assumption. Germany would have to interrupt maritime contact between France and Poland, prevent French landings on the German coast, and conduct long-range commerce warfare against French interests. The fleet the Nazis would eventually inherit was built to Zenker’s specifications. When the Reichstag believed Zenker had pressed too hard for new ships, he gave way to Erich Raeder, who took a much slower approach and would lead the navy into the Second World War.
The Reichsmarine’s first ships were a passel of leftover veterans of the pre-dreadnought era: eight battleships and eight light cruisers, plus 12 destroyers and 12 torpedo boats. The navy was limited to 15,000 men, so even this small fleet could not all be operational and two of the battleships were disarmed and used as tenders while two others remained in reserve.
The navy was allowed to replace its cruisers when they became 20 years old, and this exception applied to all of them by 1922. The Reichsmarine laid down the light cruiser Emden in late 1921 to a design very similar to the High Seas Fleet’s final class of cruisers. Only six of the allowed eight cruisers could be in service at any one time, so during the rest of the 1920s the navy laid down four more modern light cruisers as well. Runaway inflation and economic collapse delayed these for a couple of years. A final cruiser to make the full six, which became Nürnberg, was in turn delayed by the outbreak of the Great Depression and not laid down until 1934. Though this came after the republic’s fall, she was part of the Reichsmarine program rather than the Nazi one that followed.
Germany was not a party to the Washington Naval Limitations Treaty of 1922; she had her own limitations imposed by the Treaty of Versailles. Warships could not exceed 10,000 tons and could not be armed with guns larger than 11-inch (280mm). This would, it was apparently supposed, yield only coast-defense ships similar to those operated by the Swedish navy.
Zenker famously manipulated these limits to produce the armored cruiser Deutschland. She had thin protection but very long range, as befitted her role as a commerce raider. German propaganda claimed that she could outrun what she could not outfight, and outfight what she could not outrun. Though not exactly true, it made for a good tag line.
During the 1920s, many navies looked at building what the naval journals of the time called a “Washington Treaty Cruiser Killer.” This was a ship of high speed and light armor, designed to destroy the “treaty cruisers” of the time. The Washington treaties limited heavy cruisers to 10,000 tons and an armament of 8-inch guns, but put no limit on their length. Thus most navies built very long ships of relatively high speed and thin armor.
Battleships, meanwhile, were limited to 35,000 tons and 16-inch guns. Plus each signatory had an overall tonnage limit. Some thinkers pointed out, that two 17,500-ton ships with large-caliber guns could be built on the allotted tonnage for one battleship. The Washington Naval Treaty set 17,500 tons as the minimum displacement for a ship carrying guns larger than 8 inches, acknowledging this possibility. Italy actually authorized a pair of such ships in 1928, but the Great Depression scuttled them.
Zenker wanted a pair of ships like this for the German navy as well. Germany had re-entered world diplomacy in 1925 with the Locarno Pact, obtaining a permanent seat on the Council of the League of Nations and trading border guarantees with her western neighbors. The Weimar Republic appeared well on its way to re-joining the family of nations. Zenker seems to have thought an increase in the Versailles tonnage limit could be negotiated, as well as an increase in main gun caliber from 11 inches to the 12-inch size then being advocated by the British for all nations.
By 1925 at last the first three proposals were drafted, added to the 1923 studies, for five different design philosophies.
-Design 1923 "I/10" 32-knot (59 km/h; 37 mph) cruiser, eight 20.5 cm (8.1 in) guns
-Design 1923 "II/10" 22-knot (41 km/h; 25 mph) well armored ship, four 38 cm (15 in) guns.
In addition, I/10 had turbines, oil-only boilers for 80,000 shp and 4×2 210 or 208 mm turrets, plus 4x 88m, 8x50mm
II/10 had turbines steam turbines with boilers burning coal and oil for 25,000 shp, 22 knots, 2×2 150mm, 2x 88m, 2x50mm
-Design 1925 "II/30" had six 30 cm (12 in) as IV and V. here are the details:
-II/30 – Diesel 24,000 shp 21 knots, 3×2 305 mm turrets, 4x 105mm
-IV/30 – Same, 2×3 (all fore) 305 mm turrets, 2×2 150mm, 4x 105mm
-V/30 – same, 2×3 (1 fore, 1 aft) 305 mm turrets, 6x 150mm 3x 88mm
-I/28 – same, same as above, 2×2 150 mm, 6x 88mm
-II/28 – same, 3×2 (2 offset aft) 305 mm turrets, 4x 150 mm, 4x 88mm
-VI/30 – same, 2×2 (1 fore, 1 aft) 305 mm turrets, 2×2 150 mm, 4x 88mm
Design ('Entwurf') I/M26, alternative proposal for the Panzerschiffe
Entwurf II/30, one of the early designs, had six 305 mm/280 mm main guns in three twin turret and a top speed about 24-26 knots, and a 100 mm armor belt
Reichsmarine's admiral Hans Zencker wanted to lay down the first of these in 1926, but the design still needed to be finalized. The Reichsmarine 1926 maneuvers had some interesting retuens: One was that a greater speed was desirable. So two new designs were prepared, closing in on the definitive concept:
-Design 1927 "Panzerschiff A": Prepared in 1926, its first draft was ready in early 1927, but it was finalized in 1928. In between, admiral Zenker announced on 11 June 1927 that the Reichsmarine settled on the definitive armament, two triple turrets with 28 cm guns. This gave the:
-I/M26 Diesel 4,000 shp, 28 knots, 2×3 (fore & aft) 280 mm turrets, 4×2 120 mm DP, 6x 37mm
-II/M26 Diesel 54,000 shp, 28 knots, 2×3 (fore & aft) 280 mm turrets, 4×2 120 mm DP, 6x 37mm
Entwurf-3-b (): A possible successor of the Deutschland class, Similar but with larger displacement, higher speed and better Armor, up to 220mm for the armor belt
The Reichsmarine eventually settled as said above for the 28 cm (11 in) caliber, well known and for which still existed molds and machining, so not to provoke the Allies. This also lifted the burden for the engineers to design and develop, adapt to their design a brand new gun. From first draft to delivery, a new gun in peacetime could be a five years enterprise. In addition, although light, the trusted German 28 cm guns had a better muzzle velocity, so potentially better range compared to the British 12 in (305 mm) before WW1, and better anyway than 8-in guns, and with mount and breech block improvement, could also be as fast as a heavy cruiser gun.
The Reichsmarine held a conference to evaluate these designs in May 1925. Results were inconclusive, and affected by the recent French occupation of the Ruhr industrial area, the result of payment default, and depriving Germany of any option of delivering quickly a large-caliber artillery. The design staff prepared two more designs:
-Design 1925 "I/35": A heavily armored ship with a single triple turret forward
-Design 1925 "VIII/30": Less armour but two twin turrets.
The VII/30 walked on Diesel engines for a total output of 24,000 shp providing 21 knots, and two forward 12-in (30.5 cm) main turrets, 2×2 150 mm, 4x 88mm.
VIII/35 design also used a Diesel but output halved at 16,000 shp, for 19 knots, a triple forward 305 mm turret, and 6x 88mm VIII/30 also used Diesel but output reached 36,000 shp for 24 knots, with a two twin 305 mm turrets configuration, same secondaries
Accordingly, he ordered a design prepared along those lines. His cruiser killer would have good range and a thin skin, and carry eight 12-inch guns in four double turrets. Secondary guns would be nine 5.9-inch guns in the same turrets then in production for K-type cruisers, and she’d have a bank of three torpedo tubes on either side. Her armor would be the same as Deutschland, then also in the design stage, but she would have considerably greater speed (34 knots against 28). Her range would be less than Deutschland, as she carried turbines like the last Imperial battlecruiser designs rather than diesels like Deutschland.
This ship would have little chance in battle against a true battleship; her cruiser-scale armor would not stand up to heavy guns. But with a speed of 34 knots, hopefully she wouldn’t have to, and could run down and destroy enemy cruisers from well outside their gunnery range.
International diplomacy did not in fact yield the agreements for which Zenker hoped; German diplomats don’t appear to have even asked for them. That failure also doomed most of the other alternative designs for a new armored ship: coast-defense ships with 380mm (15-inch) guns, armored cruisers with 305mm (12-inch) guns, and a heavy cruiser variant with 203mm guns. Zenker did not wish to fall back to cruiser-scale guns, and without the ability to fit larger weapons on the new ship he went with the armored cruiser armed with 280mm guns that became Deutschland.
illustration from a Russian "war at sea" magazine
The Weimar Republic, that forward-looking liberal outgrowth of the collapsed German Empire, was not a peace-loving entity. Well before the rise of Adolf Hitler, the republic planted the seeds of military revival.
The Versailles Treaty and its addenda destroyed German naval power — with serious help from the Germans themselves. On 21 November 1918, as part of the Armistice provisions, the bulk of the German High Seas Fleet sailed to Scapa Flow for internment. In May 1919, the Allies informed the German delegates at Versailles that all of the ships at Scapa Flow would have to be turned over to the Allies, with most going to Britain. Rear Admiral Ludwig von Reuter reacted by ordering the fleet to scuttle itself, and on 17 June 1919 twelve battleships, five battle cruisers, eight light cruisers and fifty destroyers went to the bottom of the anchorage.
The gesture did little for Germany: The angry Allies made the Germans hand over all their remaining modern warships, and billed them for the scuttled fleet.
When the Weimar Republic’s new Reichsmarine was founded on 31 March 1921, its leaders foresaw Germany going to war against an alliance of France and Poland. Britain and the United States, they believed, would stay neutral in such a conflict. British Prime Minister David Lloyd George’s behavior during the Russo-Polish War of 1921 seemed to confirm this belief, as Britain remained aloof while Poland was nearly overrun by the Red Army.
Vice-Admiral Hans Zenker, the Reichsmarine’s commander from 1924 to 1928, prepared the navy’s building program around this assumption. Germany would have to interrupt maritime contact between France and Poland, prevent French landings on the German coast, and conduct long-range commerce warfare against French interests. The fleet the Nazis would eventually inherit was built to Zenker’s specifications. When the Reichstag believed Zenker had pressed too hard for new ships, he gave way to Erich Raeder, who took a much slower approach and would lead the navy into the Second World War.
The Reichsmarine’s first ships were a passel of leftover veterans of the pre-dreadnought era: eight battleships and eight light cruisers, plus 12 destroyers and 12 torpedo boats. The navy was limited to 15,000 men, so even this small fleet could not all be operational and two of the battleships were disarmed and used as tenders while two others remained in reserve.
The navy was allowed to replace its cruisers when they became 20 years old, and this exception applied to all of them by 1922. The Reichsmarine laid down the light cruiser Emden in late 1921 to a design very similar to the High Seas Fleet’s final class of cruisers. Only six of the allowed eight cruisers could be in service at any one time, so during the rest of the 1920s the navy laid down four more modern light cruisers as well. Runaway inflation and economic collapse delayed these for a couple of years. A final cruiser to make the full six, which became Nürnberg, was in turn delayed by the outbreak of the Great Depression and not laid down until 1934. Though this came after the republic’s fall, she was part of the Reichsmarine program rather than the Nazi one that followed.
Germany was not a party to the Washington Naval Limitations Treaty of 1922; she had her own limitations imposed by the Treaty of Versailles. Warships could not exceed 10,000 tons and could not be armed with guns larger than 11-inch (280mm). This would, it was apparently supposed, yield only coast-defense ships similar to those operated by the Swedish navy.
Zenker famously manipulated these limits to produce the armored cruiser Deutschland. She had thin protection but very long range, as befitted her role as a commerce raider. German propaganda claimed that she could outrun what she could not outfight, and outfight what she could not outrun. Though not exactly true, it made for a good tag line.
During the 1920s, many navies looked at building what the naval journals of the time called a “Washington Treaty Cruiser Killer.” This was a ship of high speed and light armor, designed to destroy the “treaty cruisers” of the time. The Washington treaties limited heavy cruisers to 10,000 tons and an armament of 8-inch guns, but put no limit on their length. Thus most navies built very long ships of relatively high speed and thin armor.
Battleships, meanwhile, were limited to 35,000 tons and 16-inch guns. Plus each signatory had an overall tonnage limit. Some thinkers pointed out, that two 17,500-ton ships with large-caliber guns could be built on the allotted tonnage for one battleship. The Washington Naval Treaty set 17,500 tons as the minimum displacement for a ship carrying guns larger than 8 inches, acknowledging this possibility. Italy actually authorized a pair of such ships in 1928, but the Great Depression scuttled them.
Zenker wanted a pair of ships like this for the German navy as well. Germany had re-entered world diplomacy in 1925 with the Locarno Pact, obtaining a permanent seat on the Council of the League of Nations and trading border guarantees with her western neighbors. The Weimar Republic appeared well on its way to re-joining the family of nations. Zenker seems to have thought an increase in the Versailles tonnage limit could be negotiated, as well as an increase in main gun caliber from 11 inches to the 12-inch size then being advocated by the British for all nations.
By 1925 at last the first three proposals were drafted, added to the 1923 studies, for five different design philosophies.
-Design 1923 "I/10" 32-knot (59 km/h; 37 mph) cruiser, eight 20.5 cm (8.1 in) guns
-Design 1923 "II/10" 22-knot (41 km/h; 25 mph) well armored ship, four 38 cm (15 in) guns.
In addition, I/10 had turbines, oil-only boilers for 80,000 shp and 4×2 210 or 208 mm turrets, plus 4x 88m, 8x50mm
II/10 had turbines steam turbines with boilers burning coal and oil for 25,000 shp, 22 knots, 2×2 150mm, 2x 88m, 2x50mm
-Design 1925 "II/30" had six 30 cm (12 in) as IV and V. here are the details:
-II/30 – Diesel 24,000 shp 21 knots, 3×2 305 mm turrets, 4x 105mm
-IV/30 – Same, 2×3 (all fore) 305 mm turrets, 2×2 150mm, 4x 105mm
-V/30 – same, 2×3 (1 fore, 1 aft) 305 mm turrets, 6x 150mm 3x 88mm
-I/28 – same, same as above, 2×2 150 mm, 6x 88mm
-II/28 – same, 3×2 (2 offset aft) 305 mm turrets, 4x 150 mm, 4x 88mm
-VI/30 – same, 2×2 (1 fore, 1 aft) 305 mm turrets, 2×2 150 mm, 4x 88mm
Design ('Entwurf') I/M26, alternative proposal for the Panzerschiffe
Entwurf II/30, one of the early designs, had six 305 mm/280 mm main guns in three twin turret and a top speed about 24-26 knots, and a 100 mm armor belt
Reichsmarine's admiral Hans Zencker wanted to lay down the first of these in 1926, but the design still needed to be finalized. The Reichsmarine 1926 maneuvers had some interesting retuens: One was that a greater speed was desirable. So two new designs were prepared, closing in on the definitive concept:
-Design 1927 "Panzerschiff A": Prepared in 1926, its first draft was ready in early 1927, but it was finalized in 1928. In between, admiral Zenker announced on 11 June 1927 that the Reichsmarine settled on the definitive armament, two triple turrets with 28 cm guns. This gave the:
-I/M26 Diesel 4,000 shp, 28 knots, 2×3 (fore & aft) 280 mm turrets, 4×2 120 mm DP, 6x 37mm
-II/M26 Diesel 54,000 shp, 28 knots, 2×3 (fore & aft) 280 mm turrets, 4×2 120 mm DP, 6x 37mm
Entwurf-3-b (): A possible successor of the Deutschland class, Similar but with larger displacement, higher speed and better Armor, up to 220mm for the armor belt
The Reichsmarine eventually settled as said above for the 28 cm (11 in) caliber, well known and for which still existed molds and machining, so not to provoke the Allies. This also lifted the burden for the engineers to design and develop, adapt to their design a brand new gun. From first draft to delivery, a new gun in peacetime could be a five years enterprise. In addition, although light, the trusted German 28 cm guns had a better muzzle velocity, so potentially better range compared to the British 12 in (305 mm) before WW1, and better anyway than 8-in guns, and with mount and breech block improvement, could also be as fast as a heavy cruiser gun.
The Reichsmarine held a conference to evaluate these designs in May 1925. Results were inconclusive, and affected by the recent French occupation of the Ruhr industrial area, the result of payment default, and depriving Germany of any option of delivering quickly a large-caliber artillery. The design staff prepared two more designs:
-Design 1925 "I/35": A heavily armored ship with a single triple turret forward
-Design 1925 "VIII/30": Less armour but two twin turrets.
The VII/30 walked on Diesel engines for a total output of 24,000 shp providing 21 knots, and two forward 12-in (30.5 cm) main turrets, 2×2 150 mm, 4x 88mm.
VIII/35 design also used a Diesel but output halved at 16,000 shp, for 19 knots, a triple forward 305 mm turret, and 6x 88mm VIII/30 also used Diesel but output reached 36,000 shp for 24 knots, with a two twin 305 mm turrets configuration, same secondaries
Accordingly, he ordered a design prepared along those lines. His cruiser killer would have good range and a thin skin, and carry eight 12-inch guns in four double turrets. Secondary guns would be nine 5.9-inch guns in the same turrets then in production for K-type cruisers, and she’d have a bank of three torpedo tubes on either side. Her armor would be the same as Deutschland, then also in the design stage, but she would have considerably greater speed (34 knots against 28). Her range would be less than Deutschland, as she carried turbines like the last Imperial battlecruiser designs rather than diesels like Deutschland.
This ship would have little chance in battle against a true battleship; her cruiser-scale armor would not stand up to heavy guns. But with a speed of 34 knots, hopefully she wouldn’t have to, and could run down and destroy enemy cruisers from well outside their gunnery range.
International diplomacy did not in fact yield the agreements for which Zenker hoped; German diplomats don’t appear to have even asked for them. That failure also doomed most of the other alternative designs for a new armored ship: coast-defense ships with 380mm (15-inch) guns, armored cruisers with 305mm (12-inch) guns, and a heavy cruiser variant with 203mm guns. Zenker did not wish to fall back to cruiser-scale guns, and without the ability to fit larger weapons on the new ship he went with the armored cruiser armed with 280mm guns that became Deutschland.
illustration from a Russian "war at sea" magazine
