u/Herfinde_NavyTD

Recognizing the limitations of relying solely on air support from the Regia Aeronautica (Italian Air Force) to counter the growing threat posed by aircraft to surface fleets, the Italian Navy proposed a new light cruiser design centered on air defense. This plan, named Settimio Bassiano, was slated for keel-laying in 1938 with an anticipated commissioning in early 1943.

​The main armament consists of twelve 13.5 cm/45 caliber guns in four triple turrets, while the anti-aircraft battery utilizes proven weaponry: twelve single 9 cm/50 caliber DP guns. Her torpedo armament comprises six 53.3 cm tubes in two triple launchers. For close-range defense, she carries a formidable anti-aircraft suite: eight twin 37 mm/54 autocannons (16 guns total) and sixteen twin 20 mm/65 autocannons (32 guns total), providing capabilities befitting an anti-aircraft cruiser.

​Her overall design is essentially an enlarged version of the contemporary Capitani Romani-class cruisers, measuring 172.5 meters in length and 18.1 meters in beam. Powered by a twin-shaft propulsion system, she could reach a top speed of 38.5 knots. Additionally, an EC.3 "Gufo" search radar was installed on the forward bridge for early detection of aerial threats.

Dinger was a large anti-aircraft destroyer design proposed by the US Navy, intended to enable larger-scale mass production by scaling down the Atlanta-class light cruiser. Conceived as a cross between the Fletcher-class destroyer and the Atlanta class, she was planned for commissioning in 1943.

​The long, slender hull measures 146 meters in length and 14 meters in beam, and was capable of a maximum trial speed of 38 knots. Her main armament consists of six twin 5-inch/38 dual-purpose mounts (12 guns total), arranged lower than those on the Atlanta class to avoid top-heaviness. Additionally, as she was expected to serve as a destroyer leader like the Atlanta class, torpedoes were not entirely omitted; she is fitted with a single 21-inch quintuple torpedo tube mount, though it likely would have been removed in the later stages of the war.

​For short-range anti-aircraft defense, she carries a mix of twin and quadruple mounts totaling 24 Bofors 40mm/56 guns, along with 14 twin 20mm/70 Oerlikon mounts (28 guns total). Integrated with Mk 51 fire control systems, these deliver formidable close-in anti-aircraft protection. She is also equipped with a large air-search radar and an SG surface-search radar.

Karl von Steinmetz was designed by the German Navy to counter French contre-torpilleurs (large destroyers) by expanding the design of the existing Type 1936A destroyer to carry a larger number of 15 cm guns, creating a new class bridging the gap between a destroyer and a light cruiser. As she was not a pure destroyer, she was not assigned a "Z" number. This planned warship was envisioned to enter service in 1944.

​While the Type 1936A was equipped with only a single twin turret alongside single mounts for its 15 cm L/45 guns, the Steinmetz standardized on twin turrets, mounting four of them for a total of eight guns. Her torpedo armament consisted of eight 53.3 cm tubes in two quadruple launchers, identical to standard German destroyers. Furthermore, with an anti-aircraft suite comprising ten twin 3.7 cm Flak M42 mounts (20 guns total), twenty 20 mm L/65 AA guns, as well as air- and surface-search radars, she possessed formidable air-defense capabilities for a vessel of her size.

​Although her overall silhouette resembled the unbuilt Type 1945-class destroyer, her hull was enlarged to a length of 141 meters and a beam of 13 meters to accommodate her heavy armament. Powered by a twin-shaft propulsion system, she could reach a top speed of 40 knots. True to her design philosophy, she would have been a formidable rival to France's large destroyers.

For her background prior to being handed over to the Republic of China, please check my previous post here.

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Even after reaching mainland China, the Yanhai's extraordinary fate continued. As the Second Sino-Japanese War escalated, the Chinese government, fearing the loss of the Yanhai—a symbolic force of the Republic of China—due to Japanese air raids, requested that she be handed over to her original manufacturer, Britain, via Hong Kong and incorporated into the British Eastern Fleet. Britain reluctantly agreed, but as Japan further expanded her front lines, they became concerned that a war between Britain and Japan and the sinking of the Yanhai would cause serious diplomatic problems. Therefore, she retreated from Hong Kong to Singapore, Trincomalee, and then Kilindini, constantly withdrawing further into the rear ahead of the Japanese advance.

Having experienced almost no combat, the Yanhai was soon returned to the Republic of China and sailed back to the mainland, only for the Second Chinese Civil War to erupt. Even here, despite being the largest warship, she was deemed of little practical military value due to the limitations of her main armament. As the Nationalist forces' disadvantage became increasingly apparent in 1948, she was loaded with cultural artifacts and other items and evacuated to Taiwan in advance. Even after the Republic of China's territory shrank to just the Taiwan islands and a few mainland pockets, the Yanhai remained the flagship of the ROC Navy. However, lacking the economic resources to afford the fuel needed to move such a massive vessel, she remained moored in port, effectively serving as a semi-fixed floating battery.

​In the 1980s, as Taiwan's economic development allowed for the introduction of newer warships, the Yanhai was finally decommissioned. However, her history was inextricably linked to the history of the Republic of China, and her preservation as a museum ship was strongly desired. Because she had not experienced intense combat and suffered minimal hull damage, she was expected to be preserved in good condition, and she was chosen to be preserved as a museum ship at the Zuoying Naval Base.

The Yanhai(烟海, Yānhǎi) was a battlecruiser design ordered from Vickers by the Republic of China government in 1915—during the Yuan Shikai administration—as a successor to the battlecruiser proposal of 1913. However, the project was frozen due to the ongoing First World War and the fragmentation of mainland China into rival warlord factions following Yuan Shikai's death. An agreement was eventually reached with the Beijing government around 1918; construction began in 1919 with a payment plan involving installments, and completion was projected for 1922.

Yet, even after the ship was built, the intended recipient—the Republic of China government—was in a state of constant political turmoil, with leadership changing every few months. Payments fell behind, and years passed with Vickers unsure of where to deliver the vessel. Although the Washington Naval Treaty granted a special exemption allowing for the ship's provisional retention pending delivery to China, the inability to finalize the transfer led to accusations of treaty violations from other nations. Just as Vickers was considering scrapping the ship, the handover was finally completed. Ultimately, the Yanhai was sailed to mainland China in 1930, after the situation had stabilized somewhat following the Nationalist Government's completion of the Northern Expedition and the purchase cost had been fully settled through a deal involving resource concessions with the British government.

While the ship's overall profile resembled that of the Admiral-class battlecruisers (such as HMS Hood), her main armament was extraordinary: four single-mount 18-inch guns, utilizing the production lines originally intended for HMS Furious. Her secondary armament consisted of eight single-mount 6-inch guns, while the anti-aircraft suite comprised eight twin-mount 4-inch high-angle guns (sixteen barrels in total). Additionally, she carried thirty single-mount 2-pounder "pom-pom" guns as smaller-caliber anti-aircraft weaponry.

With an overall length of 240.5 meters and a relatively wide beam of 31 meters, the ship possessed greater hull strength than the Furious—having been designed as a true battlecruiser—yet there were restrictions on firing full main battery salvos. Perhaps due to the weight of the main armament, her speed was lower than that of the Hood, clocking in at 27.5 knots with a four-shaft propulsion system.

The Pyrmont was originally under construction as the second ship of the Waldeck-class large cruisers, but her design was modified mid-construction to be completed as an aircraft carrier. This plan was intended to enable more efficient commerce raiding by pairing her with the Waldeck, with commissioning envisioned for 1943.

​While her overall silhouette resembled the Graf Zeppelin, which was under construction around the same time, the Pyrmont's distinctive feature was her tower-shaped island, following the trend of medium and large carriers from other nations. Her secondary armament mirrored that of the Graf Zeppelin, consisting of sixteen 150 mm/55 guns in eight twin mounts, though her 105 mm/65 anti-aircraft guns were reduced to eight guns in four twin mounts. For close-in defense, her sponsons packed an exceptionally heavy anti-aircraft suite, featuring thirty-six 37 mm M42 autocannons in 18 twin mounts, and eighty 20 mm/65 Flakvierling autocannons in 20 quadruple mounts.

​Her propulsion system remained identical to the Waldeck's three-shaft configuration, but her maximum speed increased to 36 knots, likely owing to the removal of the heavy main gun turrets. Her overall length also remained unchanged at 233.3 meters, with a flight deck measuring 210 meters long by 29 meters wide—a standard size for a medium carrier. Equipped with two elevators (one forward and one aft), her hangar featured a fully two-tiered structure with a clearance of 4.8 meters each, boasting a capacity of 50 to 60 aircraft, which rivaled that of large fleet carriers. Additionally, like the Graf Zeppelin, she was equipped with two aircraft catapults.

[Squadrons]

• Fighters: Messerschmitt Bf 109T-0 (×17)
• Dive Bombers: Junkers Ju 87C-0 (×34)
• Torpedo Bombers: Fieseler Fi 167 (×23)

If the German Navy were to engage in hostilities with Britain, the most critical path to victory would be to attack and sever its trade routes, thereby isolating the British mainland. The Waldeck was a proposed large cruiser design created for this strategy, envisioned for commissioning in 1942.

​​​Her heavy armament consisted of eighteen 203 mm/56 guns in six triple turrets, supplemented by sixteen improved 105 mm/65 dual-purpose guns in eight twin mounts. This overwhelming firepower was intended to crush and sweep away the heavy cruisers, light cruisers, and destroyers that Britain deployed for commerce protection at the time. To accommodate this massive arsenal, the cruiser boasted dimensions comparable to a battleship, with an overall length of 233.3 meters and a beam of 25 meters.

​Driven by a three-shaft propulsion system, her slender hull allowed for a maximum speed of 33.6 knots. To expedite the design and construction process, the basic hull form was an enlarged evolution of the Admiral Hipper-class, though torpedo tubes were omitted to focus entirely on gunnery duels. In addition to the dual-purpose guns, her anti-aircraft suite included thirty-six 37 mm M42 autocannons in 18 twin mounts, and eight single 20 mm/65 anti-aircraft guns.

Porto Praya is a United States Navy aircraft carrier project designed with an eye toward the future of ever-larger carrier-based aircraft. Her design incorporates mechanisms capable of seamlessly operating large land-based aircraft. Construction was planned to begin in early 1940, with commissioning expected in late 1943.

The design progressed based on data obtained from the Army's new aircraft then under development, which would later become the B-25. However, the Navy subsequently instructed that the Porto Praya be built to Panamax specifications. This required the inclusion of numerous novel mechanisms, extending the construction period to three and a half years—a lengthy duration even given America's immense industrial capacity.

With an overall length of 288 meters and a waterline beam of 32 meters, she was one of the largest aircraft carriers of her time. Her flight deck, measuring 285 meters in length and 32 meters in width, was near the absolute limit for transiting the Panama Canal. She was equipped with two 20m × 18m elevators and a slightly smaller one in the center, allowing the B-25 to be raised and lowered without issue by positioning it slightly diagonally. The hangar height was an impressive 9 meters. Utilizing a newly designed high-capacity overhead suspension system, B-25s (stripped of fuel and ammunition) could be suspended in mid-air. By offsetting their positions, it was even possible to stow aircraft in a two-tier configuration, utilizing both the hangar floor and the overhead suspension. However, because a standard carrier structure could not withstand the weight of this system—and to prepare for the impact of large aircraft landings—the flight deck was fully armored, and the hangar sidewalls were reinforced, making her an armored aircraft carrier. Her overall hull form followed the precedent of the Yorktown class; powered by a four-shaft propulsion system, she could achieve a maximum speed of 31.6 knots, enabling her to launch land-based aircraft using wind over the deck (WOD) alone.

​The ship's organic armament provided enough surface combat capability to drive off light cruiser-class vessels, featuring a main battery of eight 6-inch/47-caliber guns in four twin turrets positioned fore and aft of the island, supplemented by eight single 5-inch/38-caliber dual-purpose guns as secondary and anti-aircraft artillery. This heavy armament was the result of implementing what could be considered excessive firepower to protect the carrier as a mobile base. Her anti-aircraft suite was equally formidable to keep enemy aircraft at bay, consisting of 16 twin Bofors 40mm mounts (32 barrels) and 36 twin Oerlikon 20mm mounts (72 barrels). While the sponsons housing these weapons increased her total beam to 35 meters, exceeding the Panama Canal's limits, some of these sponsons featured a folding mechanism. By temporarily removing the anti-aircraft weapons via cranes or manual labor, the overall width could be brought within the canal's restrictions.

[Squadrons]

• Fighters: Grumman F6F (×18)
• Horizontal Bombers: North American B-25 (×28)

Akitsushima (秋津洲), a seaplane tender intended for the maintenance and resupply of the Type 2 Flying Boat (H8K), was deemed incapable of operating with flying boats on board from her construction stage due to her insufficient hull size. Therefore, the Imperial Japanese Navy planned a larger seaplane tender capable of sailing with flying boats on board; the Dorokyo (瀞峡) was the proposed design for that vessel. This ship was envisioned to enter service in 1943, the year after Akitsushima's completion.

​While her general shape is an enlarged and improved version of Akitsushima, she boasts a massive hull comparable to a battleship, with a length of 215 m and a beam of 30 m, allowing her to sail with 4–5 H8Ks on board. An elevator is located at the center of the seaplane deck, leading down to a hangar capable of storing approximately 5 small seaplanes in a disassembled state. These were intended to be used as escort floatplane fighters for the flying boats. Furthermore, she features a twin-shaft propulsion system, capable of achieving a maximum speed of 28 knots.

​For self-defense, she is equipped with six twin Type 98 65-caliber 10cm high-angle guns, also known as the "long 10cm guns," totaling 12 guns. In addition, she is equipped with a total of 36 Type 96 60-caliber 25mm machine guns, giving her the capability to respond to air raids. Furthermore, the bridge is equipped with one Type 21 radar and one Type 22 radar.

​[Squadrons]

• ​Fighters: Kawanishi N1K Kyofu (×6) ​
• Horizontal Bombers: Kawanishi H8K Type 2 Flying Boat (×5)

The Fluorite was the second ship of the Feldspar-class large light cruisers, commissioned in 1929. Following the expiration of the naval treaties, it was planned to refit her with the same 6-inch triple turrets as the first ship. However, due to the large hull of this class and her high potential for growth, she was instead slated for a comprehensive conversion to better suit air defense, which included replacing her main armament with 5.25-inch Dual-Purpose (DP) guns. This refit was completed in 1943, and she was equipped with state-of-the-art radar.

While her basic hull form is identical to the refitted Feldspar, her major defining feature is the significant improvement in anti-aircraft capabilities through the installation of eight twin 5.25-inch mounts (16 guns total). However, because the two central turrets are waist mounts positioned on each beam, the actual number of guns that can be trained on a single broadside remains fourteen guns in seven turrets, unchanged from her original configuration. Similar to Feldspar, her torpedo tubes were halved and bulges were added, resulting in improved stability but a decrease in speed.

​Her secondary battery, consisting of six twin 4-inch HA mounts (12 guns total), mirrors Feldspar. However, her light anti-aircraft armament was so heavily augmented that she could well be classified as an anti-aircraft cruiser, boasting a total of 40 Bofors 40mm guns in quadruple and twin mounts, along with ten 20mm Oerlikon cannons in five twin mounts.

The Feldspar was a proposed F-class large light cruiser designed as a successor to the Emerald class. She was conceived under the Royal Navy's view that it was high time to build a "true" large light cruiser, following the conversion of the original Courageous-class ships into aircraft carriers. She was envisioned to enter service in 1928.

​With a length of 198 m and a beam of 20 m, she boasted an exceptional size for a light cruiser of her time. Her main armament consisted of fourteen 6-inch 50-caliber guns housed in seven twin turrets, effectively doubling the firepower of the Emerald class. She was also armed with four quadruple 21-inch torpedo mounts (16 tubes total). Her anti-aircraft armament included eight single 4-inch 45-caliber Dual-Purpose guns and ten 2-pounder "pom-pom" barrels.

​Although Feldspar possessed a hull comparable to a heavy cruiser, her design was fundamentally an extension of a light cruiser, as her classification implied. Her slender length-to-beam (L/B) ratio was a testament to this, enabling her to achieve a high speed of 36 knots.

​By the time of her completion, development of the intended triple turrets had stalled, resulting in the installation of the proven twin turrets. However, the hull had been designed to accommodate a future upgrade to triple mounts.

While the Oreste Baratieri’s eighteen-gun main battery and 28.5-knot speed made her highly attractive, she suffered from several issues. Her slender hull lacked sufficient stability when firing the main battery or during hard turns, which forced severe restrictions on her salvo fire. Furthermore, her anti-aircraft capability, though potent upon completion, was becoming inadequate due to the remarkable development of aviation. To resolve these problems, a modernization refit was completed in 1941.

​First, bulges were added below the waterline, widening her beam to 33 meters, and an underwater protection system was incorporated within them to enhance her survivability. The bridge structure and masts were also updated to a more modern configuration, ensuring her command capability.

​Although her main and secondary batteries remained unchanged, her small-caliber anti-aircraft guns were greatly strengthened; the 20 mm twin anti-aircraft mounts were doubled to twelve (24 guns total), and thirty-eight 37 mm/54 anti-aircraft guns were newly added in nineteen mounts. While this extensive overhaul reduced her speed to 27.3 knots, it was still a sufficient value for a fast battleship.

After the cancellation of the unfinished Francesco Caracciolo-class, the Regia Marina (Italian Navy) possessed only obsolete battleships during the interwar period until the completion of the Vittorio Veneto-class. Historically, they attempted to bridge this gap by extensively reconstructing these older vessels, ultimately entering World War II without adequate preparation. The Oreste Baratieri represents a hypothetical design for a newly constructed capital ship during this lull, envisioned to enter service in 1929.

​To simplify the armament design, she was equipped with an astonishing eighteen 320 mm/44 guns housed in six triple turrets, repurposed and bored out from older 30.5 cm guns. Her secondary battery consisted of twelve 15.2 cm/53 twin guns arranged in six turrets rather than traditional casemates, successfully mitigating the interference of heavy seas.

​Anticipating the rapid advancement of naval aviation and aircraft carriers, her anti-aircraft suite featured sixteen 10 cm/47 dual-purpose guns in eight twin mounts, complemented by twelve 20 mm anti-aircraft guns in six twin mounts.

​Measuring 225 meters in length with a 30-meter beam, her hull was remarkably long and slender for a battleship. Powered by a four-shaft propulsion system delivering 136,000 shp, she could achieve a maximum speed of 28.5 knots, making her a highly capable fast battleship.

​While her overall profile retained a somewhat archaic silhouette—characterized by the towering tripod masts fore and aft—her command and control capabilities were well secured by a substantial, imposing tower-like forward bridge.

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However, upon her completion, the vessel suffered from several inherent design flaws that required urgent rectification. (While one might argue these issues should have been resolved during the drawing-board phase, such post-commissioning defects were historically quite common in actual naval architecture.)

The Dlinnyy (Длинный) was a proposed anti-aircraft cruiser developed by the Soviet Navy in response to the urgent need for fleet air-defense vessels capable of protecting the fleet from German air attacks. Under this concept, existing weapons systems were adopted wherever possible. Had the ship been built, it would not have entered service in time for either the war against Germany or Japan, and is envisioned here as entering service in 1945, after the end of the Second World War.

Its main battery consisted of six twin 130 mm/50 gun mounts, while anti-aircraft defense was provided by eight twin 76 mm/55 dual-purpose gun mounts. Additional armament comprised forty 37 mm/67 anti-aircraft guns in a mixture of twin and quadruple mounts, giving the vessel a formidable anti-aircraft capability. Torpedo armament consisted of four triple 533 mm torpedo tube mounts.

Because its main guns were of destroyer-caliber, the Soviet Navy classified the vessel as a large anti-aircraft destroyer rather than a cruiser. Its name was likewise derived from the adjectives traditionally assigned to destroyers. Nevertheless, at 180 m in length with an 18 m beam, the ship was clearly cruiser-sized by contemporary standards, leading to considerable debate among foreign naval observers. However, with the London Naval Treaty already obsolete and the Soviet Union never having been a signatory, no serious diplomatic objections followed.

In appearance, the vessel represented something of a hybrid between contemporary Soviet destroyers and light cruisers. Powered by a twin-shaft propulsion system producing 99,000 shp, its long, slender hull enabled a maximum speed of 40 knots.