Hwaju-class battlecruiser: Difference between revisions
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| <imgur w="300px">CidZ2SG.png</imgur> Hwaju in 1915 after delivery to Menghe.
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| Class overview | |
|---|---|
| Name: | Hwaju class |
| Operators: | Greater Menghean Empire |
| Preceded by: | Chŏlsŏng-class battleship |
| Succeeded by: | Songrimsŏng-class battleship |
| Built: | 1912–1917 |
| In service: | 1915–1941 |
| Planned: | 3 |
| Completed: | 2 |
| Cancelled: | 11 |
| Lost: | 2 |
| General characteristics (as built) | |
| Type: | Battlecruiser |
| Displacement: |
list error: <br /> list (help) |
| Length: |
list error: <br /> list (help) 204.5 m (waterline) 206.1 m (overall) |
| Beam: | 23.4 m |
| Draft: | 9.00 m full load |
| Installed power: |
70,000 shp 4 steam turbines 45 water-tube boilers |
| Propulsion: | 4 shafts |
| Speed: | 27.8 knots |
| Range: | 4,500 nm at 14 knots |
| Complement: | 1,057 |
| Armament: |
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| Armor: |
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| Notes: | 1: Emil-si converted to an aircraft carrier |
| General characteristics Baekjin, 1939 | |
| Type: | Heavy Cruiser |
| Displacement: |
list error: <br /> list (help) |
| Length: |
list error: <br /> list (help) 204.5 m (waterline) 206.1 m (overall) |
| Beam: | 25.4 m |
| Draft: | 8.99 m full load |
| Installed power: |
152,000 shp 4 steam turbines 12 water-tube boilers |
| Propulsion: | 4 shafts |
| Speed: | 33.2 knots |
| Range: | 6,000 nm at 15 knots |
| Complement: | 1,391 |
| Armament: |
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| Armor: |
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The Hwaju-class battlecruisers (Menghean: Hwaju-gŭb Gosok Jŏnham) were a family of battlecruisers built for the Federative Republic of Menghe during the 1910s. As Menghe's domestic shipbuilding industry was still immature but the designers wanted state-of-the-art ships, they were ordered from Tyran; delivery of the Emil-si and Baekjin was delayed until 1920, as the War of the Sylvan Succession had broken out while they were still under construction, and the Royal Navy commandeered them for its own purposes. This made them the last Menghean capital ships constructed abroad by a foreign power.
Under the Septentrion Nine-Power Naval Treaty, the Hwaju and Baekjin were converted into "large cruisers" with 20 centimeter main guns, occupying a special category between battleships and heavy cruisers. The Emil-si, which had been converted into an experimental aircraft carrier in 1921, was further modified during this period. As they lacked the armor or firepower to engage capital ships, the Imperial Menghean Navy used the "large cruisers" as commerce raiders during the Pan-Septentrion War, sending them alone or with light escort into the Helian Ocean to intercept Allied supply convoys bound for Hemithea and Meridia. Baekjin was lost in early 1940 during an engagement with the Tyrannian battleship HMS Warchild, and Hwaju was sunk by carrier aircraft in 1941.
Background
During the 1910s, the Menghean Navy began taking more ambitious measures to build up its fleet of capital ships. Despite an early focus on light torpedo boats, the Navy was growing increasingly concerned about the threat posed by dreadnought battleships, and its leaders determined that Menghe needed to obtain its own ships in this category. This need resulted in the construction of two Donghae-class battleships in Tyran and two Chŏlsŏng-class battleships domestically with imported foreign guns and equipment.
The development of faster foreign battlecruisers, however, led the Menghean Navy's leaders to express doubt over whether the slow Donghae and Chŏlsŏng classes would be adequate for national defense needs. In 1911, the Navy successfully pressured the Federal Assembly to approve the ordering of three dreadnought-style battlecruisers to fill this gap as a supplement to the slower battleship fleet. As the Navy wanted state-of-the-art propulsion systems to ensure maximum speed, they once again turned to a shipyard in Tyran for the ships' construction. Three hulls were laid down in 1912, 1913, and 1914 respectively.
The first ship in the series, Hwaju, was delivered on schedule in 1915, but the outbreak of the War of the Sylvan Succession shortly afterward interfered in their construction. Tyran initially halted new work on the ships due to the demand for steel elsewhere, postponing their delivery indefinitely. As the war escalated in 1916, Tyran resumed work on fitting-out the second and third hulls, but pressed them into service with the Royal Navy to increase its wartime strength. The second hull was commissioned into the Royal Navy as HMS Princess Anna, and the third, HMS Saint Christopher, was completed as a partial aircraft carrier with a flight deck covering 2/3 of its length.
Tyran's requisitioning of the incomplete Baekjin and Emil-si infuriated the Menghean Navy's leadership. At a time when a world war was raging around them, the Menghean Navy was left with only four dreadnought battleships and one battlecruiser, a small fleet compared to those of the other great powers. This perceived vulnerability led the Navy to order the construction of three Songrimsŏng-class battleships domestically to fill the gap, and led to the intensification of Menghe's domestic shipbuilding program in the long run.
After the end of the War of the Sylvan Succession, Tyran and Menghe entered into negotiations over the transfer of the ships, one of which was already a partial aircraft carrier. Both were commissioned into Menghean service in 1919, with the Emil-si serving as an experimental aircraft carrier; Menghe ordered a wing of carrier-capable aircraft delivered with her. From this point onward, Menghe would build all of its major warships domestically.
Description
Armament
As ordered, the Hwaju-class battlecruisers had a main armament of ten 12-inch (305mm) L/50 Mark XI guns of Tyrannian design and construction. These were the same type used on recently-constructed battleships and battlecruisers of the Royal Navy. In fact, at the time she was laid down, the Hwaju had a heavier broadside than any other Royal Navy battlecruiser under construction, able to bring all ten guns to bear on an opponent. The guns were arranged in five two-gun turrets following an AB-XYZ layout, with turret Y facing forward. The guns could elevate to only +15 degrees, another constraint common at the time but later limiting, for a maximum range of 19,300 meters. Ammunition stowage totaled 100 rounds per gun, and rate of fire was between 1 and 2 rounds per minute.
The ships' secondary armament consisted of twelve 125mm L/50 Type 10 naval guns. These were of Menghean design and construction, and were shipped to Tyran for the fitting-out of the Hwaju class. In Tyrannian service, the Princess Anna and Saint Christopher were completed with BL 4-inch Mk VII naval guns for ammunition and range table commonality with other ships of the Royal Navy.
After the ships arrived in Menghe, they were fitted with four 7.5cm Type 15 high-angle guns of Rajian construction for anti-air defense. Close-range AA defense came in the form of six water-cooled Maxim guns on pintle mounts.
Protection
Unlike the Chŏngdo-class battleships which followed ten years later, the Hwaju-class were "true" battlecruisers, with main belt armor 150 millimeters thick over the citadel and 100 millimeters thick at the fore and aft belts. The main battery barbettes were also 150 millimeters thick, as were the turret face and sides. Horizontal protection consisted of a single 50-millimeter armor deck over the citadel. This armor scheme was only sufficient to protect the ships from cruiser gunfire, and left them vulnerable to contemporary battleships' guns at all practical combat ranges.
As built, the Hwaju-class battlecruisers lacked any kind of torpedo protection, apart from torpedo nets which they could deploy while anchored or in port. They did have some internal compartments which could be sealed to contain flooding, but only fuel tanks on either side of the machinery rooms, a sacrifice intended to reduce beam and thus improve maximum speed. During interwar refits, both the large cruisers and the experimental carrier would be refitted with anti-torpedo bulges to improve underwater protection, a change somewhat compensated for by the addition of newer and more efficient engines.
Propulsion
Propulsion from the class came from four steam turbines, each one developing 17,500 shaft horsepower, in the space between the X and Y turrets. Steam for the turbines came from 45 Yarrow boilers of Tyrannian design and manufacture, grouped beneath three funnels. Like other Menghean capital ships of this period, they were entirely coal-fueled; a system for spraying oil onto the coal for a higher burn rate was considered, but ultimately rejected. At full power, the Hwaju could reach a top speed of 27.8 knots, respectable for the time and on par with other battlecruiser classes.
As "Large Cruisers"
<imgur thumb="yes" w="400" comment="First reconstruction of the Hwaju, with 250mm guns and original propulsion system.">fb9Y1LD.png</imgur> After the signing of the Septentrion Nine-Power Naval Treaty in 1923, Menghe was restricted to seven capital ships: the battleships Chŏngdo, Sunju, Anchŏn, Haeju, Songrimsŏng, Daegok, and Gyŏngsan. Due to the very recent delivery of the Baekjin, however, Menghe was able to successfully negotiate for the retention of both battlecruisers in the Hwaju class, as long as they were refitted to "large cruisers" with 250mm guns and no armor upgrades. The Emil-si, now classified as a separate ship class, was retained as a training carrier, with the requirement that her flight deck be extended all the way forward to replace the A and B gun turrets.
First reconstruction
Because Menghe's two capital-ship-sized drydocks were still busy working on the Chŏngdo-class battleships, the Hwaju and Baekjin were first stripped of their guns as a temporary treaty-compliance measure. This also gave the Navy time to invest in the development of a current-generation 250mm gun. The battlecruisers were moved into two newly excavated drydocks at the Kimhae Naval Yard in 1925 for a more thorough reconstruction, prompting negotiation among treaty signatories over whether the treaty defined "10th year of service" as time since commissioning or time since the laying of the keel. Time since commissioning won out, and the planned refits were reduced to the installation of the newly designed 250mm L/45 Type 26 guns. The supporting arms for the torpedo nets were removed in preparation for the installation of anti-torpedo bulges, but this was called off until the full refit period.
Second reconstruction
<imgur thumb="yes" w="400" comment="Hwaju after her second reconstruction. Note the new turrets and funnels, anti-torpedo bulge, revised superstructure,a dn floatplane catapult.">6KYE00w.png</imgur> Both ships in the series were brought into drydock for a second major reconstruction in 1929, ten years after Baekjin was delivered to Menghe. By this time, Kwon Chong-hoon's government was in power, and the Navy had received increased funding for construction of non-regulated ships, though it still held to its pre-coup defensive doctrine.
In the realm of protection, the designers replaced the 6-inch armor belt with a 200mm one, and increased the deck armor above the citadel to 75 millimeters. They also added anti-torpedo bulges on the sides, bringing a much-needed increase in underwater protection. An additional 50mm armor plate beneath the main belt served as a torpedo bulkhead, and helped stop shells which struck the water ahead of the ship from continuing through below the main belt into the citadel.
Internally, the machinery section was gutted and replaced with a more efficient configuration using twelve larger boilers in place of 45 small ones. These burned oil rather than coal, and were state-of-the-art models, generating considerably greater output for the same internal space. The use of liquid fuel required a redesign of the internal coal bunker, with vertical tanks on either side of the machinery spaces to further supplement the added torpedo protection. The turbines were replaced with newer types capable of handling higher steam pressures, increasing maximum output to 38,000 horsepower per shaft or 152,000 horsepower total. Even with the increase in beam due to the new torpedo protection, this change allowed the Hwaju-class to reach a top speed of 33.2 knots, faster than the Madaesan-class cruisers.
More curious changes were applied to the main armament. While the original construction plan had been to retain the 250mm guns, the Navy concluded from its assessment of foreign ship construction that any hostile ship classes protected against 200mm SAP shells were also protected against 250mm and 300mm shells. Therefore, they replaced the main armament of the Hwaju-class yet again, giving each ship five three-gun turrets fitted with the 200mm L/50 Type 29 naval gun. This weapon was able to penetrate the belt and deck armor of all Sylvan and Tyrannian heavy cruisers at regular combat ranges, while increasing the number of shells per broadside by 50 percent.
Operational history
During the interwar period, the Imperial Menghean Navy grappled with the question of how best to use its large cruisers, which had no direct counterpart in any foreign navy. Their main guns could easily penetrate the armor of any contemporary heavy cruiser, and their armor could withstand 8-inch shells at regular combat ranges; yet in both penetration and protection, they were incapable of fighting a battleship on equal terms. The pre-reform Menghean Navy treated them as "fleet interceptors" which could pick off enemy scout cruisers. After the April 11th Incident, the new Navy leadership pivoted to a more offensive mindset, modifying the ships for greater operational range in violation of the Nine-Power Naval Treaty and planning to use them on commerce raiding duties. There, the Navy reasoned, they were unlikely to encounter any opponent larger than a heavy cruiser, and their ample guns could devastate convoys and their escorts.
When Menghe declared war on Sylva in 1935, the Hwaju and Baekjin initially remained in reserve, due to concerns that the Sylvan Flota Oriental could sortie from Innominada and intercept them. As the war entered its second year with the Sylvan Navy's battleships still in port, the two large cruisers grew increasingly aggressive in their open-ocean raids, making several stops in Ostland to take on fuel and supplies. Due to the long range required and the need for light vessels elsewhere, they usually operated alone during these missions, supported by the refueling ships Badasaja and Aengmujogae. The raiding tactics continued after Tyran declared war on Menghe in 1938, posing a serious threat to the supply line between Casaterra and Khalistan.
Sinking of the Baekjin
<imgur thumb="yes" w="400" comment="Baekjin as she appeared when setting off on her final voyage.">2ZXypIn.png</imgur> In late 1939, Tyrannian military intelligence teams made a breakthrough in deciphering the Imperial Menghean Navy's radio codes, using work which they had accumulated by intercepting signals before the start of the war. With this information, they hoped to estimate the positions and courses of the Hwaju and Baekjin and route convoys around them, reducing shipping losses. Yet as the ships spent most of the time operating on radio silence, information on their movements was rare, and Royal Navy intelligence still relied primarily on distress signals from ships lost to their attacks.
On January 7th, 1940, a Tyrannian convoy guarded by the escort carrier HMS Greenwich received reports that the Baekjin was operating northeast of their position. After a reconnaissance plane confirmed the ship's location, the Greenwich launched a formation of twelve Blackburn Skuas to attack it. As the captain of the Baekjin did not expect serious aerial resistance, he had taken off some of the ship's medium-caliber AA guns in port prior to the mission, and her crew did not immediately spot the first wave of planes. One of the first bombs dropped struck the deck amidships, missing the funnels but destroying the port-side catapult and damaging one of the dual 10cm anti-air guns. The ship remained largely operational, however, as the high-explosive bomb had exploded on the deck rather than below it. The second wave of four aircraft failed to score any hits, leaving only the final group. By this time, the Baekjin was conducting evasive maneuvers, and her gun crews were on high alert. Braving a barrage of small-caliber and flak fire, Lieutenant Peter Watson closed with the ship from behind and dropped a 500-lb bomb toward the quarterdeck, later reporting that he had hoped to destroy the ship's rudder. The bomb landed off the starboard side of the deck and exploded in the water - Lt. Watson initially reported it as a miss - but the shock of the detonation sheared off the outermost starboard propeller and warped the shaft, causing further damage to its connection with the hull. The Royal Navy lost one Blackburn Skua in the attack, with two more seriously damaged but still able to return to the carrier; the captain of the Greenwich initially wanted to press the attack, but as the carrier was mainly equipped for anti-submarine warfare, she did not have enough high-explosive bombs for a second wave.
The loss of a starboard propeller shaft did not immobilize the Baekjin, but it did present serious problems. The warped shaft had torn part of the ship's plating at its connection to the hull, flooding three watertight storage compartments. Furthermore, in order to balance the ship's propulsion, the outermost port turbine could no longer be used, forcing the Baekjin to rely on her two inner propeller shafts only. At half power, she could only manage 25 knots at full output, and even this speed reportedly resulted in increased leaking around the seal to the starboard shaft. Judging that it was too dangerous to continue raiding with this damage, Captain Kim Tae-yŏn decided to return to Menghe for repairs.
Using continued intercepts of Menghean radio transmissions, the Royal Navy outpost in the Acheron Islands was able to discern the approximate position of the returning cruiser as it limped toward the Strait of Portcullia, and on January 20th a flying boat from the islands spotted the Baekjin 500 kilometers to the northwest. The battleship HMS Warchild sailed out on an intercept course, bringing along two light cruisers as her escort. As Baekin had lost her port seaplane to bomb damage and her starboard one was still suffering maintenance issues, she had no reconnaissance of her own, and the IMN was reluctant to dispatch the battleships Anchŏn and Haeju to rendezvous at sea as they feared that this could give away the position of the Baekjin.
At 1546 hours on January 21st, the watch on the Baekjin spotted the Warchild's masts on the horizon, followed by the masts of two destroyers. Captain Kim ordered an immediate turn to the north, hoping to escape to a captured port in Maverica, but with only two turbines running, the Baekjin was slightly slower than the Warchild. The latter ship opened fire at 1652, and as the engagement continued, her shell splashes drew progressively closer. Baekjin returned fire, concentrating at first on the light cruisers and scoring some hits. Yet she could not inflict any damage on the Warchild with her main guns, and her remaining Type 23-II torpedoes lacked the range to hit the Warchild unless Captain Kim took the risk of slowing down until the range closed to under 11,000 meters.
A direct hit to the Baekjin's X turret broke through its front armor and disabled it, though the blast failed to spread to the magazines below. Roughly ten minutes later, at 1725, another main battery shell penetrated the citadel rear bulkhead and passed into the aft turbine room, narrowly missing the main battery magazines again but detonating on top of her turbine rooms. This left her dead in the water except for emergency backup generators, with three hostile warships rapidly closing in from behind and fires burning on the aft deck. Kim Tae-yŏn issued the order for all hands to assemble on deck and prepare to abandon ship, but gathered a group of volunteers to head into the lowest decks and make preparations to scuttle the Haeju so that she would not fall into enemy hands. As the remainder of the crew climbed aboard the lifeboats, the volunteers opened the seacocks and the doors between internal watertight compartments.
Initially suspecting that the Baekjin was attempting to close the range and launch torpedoes, the Warchild continued to fire on the stricken ship, scoring a third hit on the starboard deck near where the first bomb had landed two weeks earlier. Only when the range had closed to 9,800 meters did the Royal Navy realize that the crew of the Baekjin was climbing into lifeboats. The light cruiser HMS Harrington moved ahead to pick up survivors, preparing a boarding party to take control of the ship if possible. As she drew to within a kilometer, however, a cloud of smoke issued from the vents over the aft turbine rooms, followed by an explosion which tore a hole in the ship's side beneath the X turret. The stern, already sitting low in the water, began to draw in water, and the bow started rising into the air; the captain of the Harrington initially considered a boarding operation to attempt to contain the flooding, but decided that it would be too dangerous a risk for such a badly damaged ship, and instead circled the ship to pick up survivors.
In popular culture
In Tyran, the campaign to intercept the Baekjin became a significant moment of national pride, signaling the first victory against a Menghean capital ship and a major step in protecting shipping between Casaterra and Meridia. The 1960 black-and-white film Hunt for the Paik Chin, using the ship's wartime romanization, brought the story into popular memory, tracing the full series of events from the breaking of the IMN operational code to the ship's explosion on the retreat. A more recent (2011) Menghean film, Last Voyage of the Baekjin, presented events from the IMN's perspective, including the popularized claim that Kim Tae-yŏn ventured below decks to help scuttle the ship and died after volunteering for the certain-death task of breaking open the water ballast compartments under the bow.
Accounts differ as to the cause of the Baekjin's sinking. Multiple Menghean sailors pulled from the water stated that Captain Kim had ordered the formation of a scuttling party and chosen to go down with his ship. Some reported seeing him on the bridge while descending to the lifeboats, while others claimed that he had joined the volunteers himself in the suicidal mission to flood the lower compartments. Eager to present news of a victory and cover up the failure to capture the battlecruiser, Tyrannian newspapers reported that the Baekjin was sunk by gunfire from HMS Warchild, and long after the end of the war some Tyrannian and Columbian historians promoted the view that the explosion which finished the Baekjin was the result of a magazine fire rather than a deliberate detonation, which would have required time and preparation which the crew did not have. A Menghean expedition in 2016 uncovered the wreck and reported that the Kingston valves along the bottom of the hull were indeed open, confirming the scuttling hypothesis, though critics have questioned the impartiality of the expedition and argued that the open valves still did nothing to rule out an accidental magazine explosion.
See also