Imperial Menghean Navy

The Imperial Menghean Navy (Menghean: 대멩제국해군 / 大孟帝國海軍, Dae Meng Jeguk Haegun), often abbreviated IMN in Tyrannian-language literature, was the naval arm of the Greater Menghean Empire. Prior to Kwon Chong-hoon's successful military coup in February 1927, it was known as the Menghean Navy (대멩해군 / 大孟海軍, Dae Meng Haegun), the "Imperial" added to reflect Kwon's ambitious plans to restore Menghean supremacy in the South Menghe Sea. Its counterpart on land was the Imperial Menghean Army, and the two services aggressively competed for priority even after a unified command structure was imposed in 1932. As the Greater Menghean Empire lacked an independent air arm, both the Army and the Navy operated their own aircraft, a practice carried forward to the present.

During the interwar period, the IMN carried out an ambitious armament and upgrading program, attempting to achieve the maximum possible combat capabilities allowed by the tonnage restrictions in the Septentrion Nine-Power Naval Treaty. This aggressive emphasis on shipbuilding predated Kwon's 1927 coup, however, as from the War of the Sylvan Succession onward the Menghean Navy had poured enormous resources into building up a world-class battleship fleet. Initially, the aims of this construction program were primarily defensive, but in 1932 Kwon Chong-hoon and the upper political leadership orchestrated a reshuffling of the Navy's top ranks, bringing in more "offensive-minded" officers and establishing a joint command structure with the Imperial Menghean Army.

After Menghe's surrender to the Allied powers in 1945, the Imperial Menghean Navy was disbanded and its personnel dismissed. Some surviving warships were distributed to the Allied powers as prize ships, while others were sold for scrap. A small number of surviving ships were returned to the Republic of Menghe Navy in 1955 to form the basis of its own navy, and several of these were passed on to the Menghean People's Navy after the Menghean War of Liberation.

Origins

Treaty restrictions

Main article: Septentrion Nine-Power Naval Treaty

Pre-war history

April 11th Incident

Tensions came to a head on April 11, 1932, when Kwon Chong-hoon announced that "loyal and right-minded officers" within the Navy had uncovered "treasonous and seditious talk" among the Navy's upper leadership, including discussion of early plans for a coup. Whether such discussion actually happened remains unclear; in their memoirs, the naval leaders involved denied the existence of a nascent coup plot, and the "loyal and right-minded officers" who revealed this information to the political leadership were never identified by name.

Nevertheless, the April 11th Incident gave Kwon a much-needed pretext to bring the Navy under his control. He ordered the immediate dismissal of nine high-ranking officers supposedly involved in seditious discussion, including the Minister of the Navy, as well as their most trusted subordinates. In their place, he appointed a group of his own trusted allies within the Navy, and created a "Joint Strategic Planning Board" which . Kwon himself was said to have favored show trials and execution, but after the replacement staff protested that this could irreparably deepen the Army-Navy rift, he instead confined the accused officers to house arrest.

In effect, the April 11th arrests brought the Navy's period of autonomy to an end. While the Joint Strategic Planning Board did not render the Navy subordinate to the Army, as some historians formerly claimed, it did render it subordinate to Kwon himself, who favored the Army's war aims. Indeed, funding to the Navy increased after this incident, despite protests from the Army upper leadership. The Board also markedly improved Army-Navy coordination, ending the escalating Army-Navy rivalry which had been a defining feature of Menghean politics during the preceding two decades. The two services still had their differences in procedure and doctrine, but in general they coordinated better than the Imperial Dayashinese Army and Imperial Dayashinese Navy, as demonstrated early on by the amphibious operations against Innominada and Khalistan.

The IMN in the Pan-Septentrion War

Strength of the Menghean Navy in May 1935
Ship type	Active	Incomplete
Fleet carriers	2	0
Battleships	7	0
Super-heavy cruisers	2	2
Heavy cruisers	6	4
Light cruisers	18	3
Destroyers	75	23

While conventional Menghean historiography states that the Pan-Septentrion War in the Eastern Hemisphere began in 1933 with Menghe's declaration of war against Themiclesia, the Imperial Menghean Navy did not see any combat until two years later. The small Themiclesian navy, which at this point consisted of one Wickes-class destroyer, two ceremonial sailing ships, and a host of other harbor vessels and tugboats, did not leave port, and all fighting took place on the arid steppe of landlocked Dzhungestan. The Navy did propose in 1934 to send the battleships Anchŏn and Haeju, along with a small escort force, to patrol Themiclesia's coast as a show of force and hopefully induce a surrender, but Maverica and the Organized States threatened diplomatic sanctons if such an operation were carried out and refused to provide use of their ports for refueling.

For the Menghean Navy, the war began in 1935, when Menghe declared war on Sylva in response to an escalating dispute over the status of Altagracia. The IMN played a starring role in the opening hours of the Menghean attack, bombarding Altagracian defensive positions in support of the Army's advance. Aware that Menghe could mass a superior force against it but unable to request reinforcements from Casaterra due to fears over Ostland's military aggression, the Sylvan Flota Oriental remained in Maracaibo for the first three years of the war, leaving Menghe with naval supremacy across the Hemithean theatre. Without having to contend with enemy warships, the IMN focused on supporting the Army's efforts in Innominada, bombarding coastal positions, escorting troop transports, and intercepting Sylvan supply convoys.

Even in the absence of any major surface actions, this stage of the conflict provided valuable experience in auxiliary aspects of naval warfare. After Sylvan land-based aircraft achieved early successes in damaging or driving off Menghean light vessels, Navy ship designers realized that they, like all other interwar powers, had seriously overestimated the effectiveness of shipboard AA. In the short run, this resulted in a hasty campaign to up-arm Navy warships with additional 12.5mm machine guns, or with older anti-air guns pulled out of storage; in the long run, it led to the development of the 37.5mm Type 38 anti-air gun. Amphibious operations along the Innominadan coast in 1936, the largest in the world at the time, also gave the IMN a change to practice amphibious operations, allowing them to test and fine-tune their doctrine, procedures, and equipment. Due to the necessity of attacking lightly defended areas and the availability of lightly armed coastal vessels, the Marine Infantry recognized early on the value of medium-caliber (130mm) gunfire for coastal fire support, and began attaching dedicated radio operators to landing units to direct naval gunfire from destroyers and cruisers during the landing operation.

The Imperial Menghean Navy's first major confrontation with a parity force came at the Battle of the Portcullia Strait, shortly after Tyran entered the war. In the last naval battle in which both sides fought in a conventional line of battle, Admiral Cho Sŭng-chŏl successfully lured Rear Admiral Andrew Hurst's Task Force Q into an engagement with his numerically superior Combined Fleet, sinking one capital ship and severely damaging three others. Combined with the loss of the carrier HMS Furious to Dayashinese aircraft the day before, and the loss of one of the damaged battleships to a submarine attack three months later, this battle re-established Menghean naval supremacy in the Eastern Hemisphere and opened the way for the invasion of Khalistan and the free raiding of supply convoys bound for Maverica and Meridia.

Planning and doctrine

Ministers of the Navy, 1901-1945
Name	Term in office
O Gwang-sik	1901-1906
Sŏn Gwang-hwan	1906-1908
Chae Dong-chŏl	1908-1912
Yun Sŭng-jae	1912-1915
Baek Jŏng-hwan	1915-1922
Ha Jun-hyŏk	1922-1923
Gu Gyu-chŏl	1923
So Gi-tae	1923-1926
Pak Dong-ha	1926-1932
U Gyŏng-tae	1932-1934
Jŏn Sŏng-nam	1934-1939
Hyŏng Chang-ho	1939-1941
Go Jun-tae	1941
Kang Ji-hwan	1942-1944
Sin Mu-yŏng	1944-1945
Kim Tae-hyŏn	1945
important figures in bold

Background

While the Army was the most active hotbed of nationalism in interwar Menghe, and Kwon Chong-hoon himself seized power on behalf of the Army without so much as consulting the Navy beforehand, the Navy's own militarist aims predated Kwon's rise to power. The Navy's concerns, which led it to demand expensive shipbuilding programs even as Menghe's weak economy struggled to support the cost of maintaining the existing fleet, stemmed from the disastrous experiences of the Uzeri Rebellion and the Sylvo-Menghean War in the early 19th century. During these conflicts, Western naval powers armed with superior cannons and, in the latter case, steam propulsion had obliterated the Myŏn dynasty's large, disorganized, and outdated junk fleets. Throughout the early 20th century, Menghean naval planners were painfully aware that they hailed from a poor country rife with internal strain in a region ringed with colonies. A strong navy, in their view, was a precondition for continued independence.

After Menghe's unification, Vice Admiral O Gwang-sik, the first Minister of the Navy, advocated for the integration of the Namyang and Sinyi navies into a combined force under central authority, rather than federal or regional fleets. He also persuaded the Federal Assembly to allocate funding for new ship construction, at a time when the Prime Minister's priority was to draw down the size of the fleet. Aware that Menghe could not match the strength of the largest navies, O invited prominent Sieuxerrian theorists of the Jeune École school to serve as advisors, and emphasized the construction of small, agile torpedo boats to counter enemy battleships.

Nevertheless, as the young Menghean Navy matured, so did the threats around it. After the emergence of a dreadnought arms race in the 1900s, Menghe ordered two Donghae-class battleships from New Tyran, forming the core of a new fleet. As part of the same shift to a capital ship focus, the Menghean Navy began bringing in more Tyrannian naval advisors. By 1915, Menghe had laid down its first domestically designed battleship, and by 1923 it operated the 6th largest capital ship fleet in the world. The War of the Sylvan Succession played a key role in enabling this growth, allowing Baek Jŏng-hwan - the "father of the Menghean Navy," even though he was only the fifth Navy Minister - to justify expensive new shipbuilding projects and demonstrating through naval combat in Casaterra that battleships remained a key element in any surface fleet.

Defensive Fleet and Decisive Battle doctrines

Menghean naval doctrine under Baek Jŏng-hwan centered on the "defensive fleet," a force of world-class battleships which would head off an enemy invasion force in a direct engagement. Jeune École torpedo boats still played a role in Baek's war plans, but only as a supporting force which would wear down the enemy fleet during its approach and interfere in its movement along the Menghean coast. Operating with greater freedom of movement, the defensive fleet could mass a formation of capital ships ahead of any threatened port, heading off an invasion. As the Menghean Navy grew, Baek expanded this theory to include the "combined fleet decisive battle," in which the Menghean Navy would mass all of its capital ships into a single battle line and attempt to engage and destroy the attacking fleet after nighttime torpedo attacks had already worn it down.

Key to this approach was its defensive nature. Though theorizing seventy years later, Baek was still gripped by the mindset of the Sylvo-Menghean War, and expected that any major war would involve a hostile fleet attempting to secure a port city as a bargaining chip or landing area. As such, he promoted a ship design philosophy which traded range and speed for weaponry and protection: the Menghean fleet would only need enough fuel for a brief sortie off the coast, and it would only need enough speed to get in front of an approaching threat. At most, the Navy would only need a few fast vessels to head off unexpected incursions or scouting forces. He also observed that as the larger colonial powers had to police and protect far-flung empires spanning multiple continents, they might only be able to bring half of their total naval assets to the war, allowing Menghe to gain a numerical advantage by massing its capital ships together in a Combined Fleet. Finally, Baek hoped that the Menghean Navy could defeat the enemy fleet in a single decisive battle before it could secure any foothold on land, thus forcing the humiliated opposing side to the negotiating table without the need for the kind of prolonged war which Menghe's weak economy would be unable to support.

These assumptions and conclusions continued to motivate the Menghean Navy and the Imperial Menghean Navy long after Baek Jŏng-hwan's retirement, and they had a profound influence on Menghean ship design. The Madaesan-class cruisers, for instance, were slow and short-ranged, but had the best protection out of all their contemporaries, with 150 millimeters of belt armor and underwater anti-torpedo bulges. The Navy also continued to procure large numbers of smaller vessels not regulated by the treaty system, such as the Myŏnma-class torpedo boats and Type 24 motor torpedo boats. Long-range offensive capability, by contrast, fell by the wayside, as it was seen as unnecessary in the kind of war scenario Baek envisioned.

Shift to offensive warfare

After the April 11th Incident, which resulted in a reshuffling of the upper staff and the dismissal of Navy Minister Pak Dong-ha, the Imperial Menghean Navy began to change its doctrinal priorities. The Joint Strategic Planning Board, created to manage Army-Navy cooperation, became an avenue through which Kwon could bring the Navy's chain of thought in line with his own. Kwon pointedly ridiculed the Navy's former band of "defensive-minded" officers, and his replacement appointees all aligned themselves with Kwon's offensive aims: namely, the use of the Navy's forces to expel colonial powers from what the nationalists viewed as Menghe's rightful sphere of influence.

New priorities for the Navy did not translate into an abandonment of all previous doctrinal work, and IMN planners and commanders would continue to focus on the decisive battle strategy before and during the war. The truly consequential changes took place at the level of grand strategy. While the IMN under Pak still envisioned operations that were confined to the South Menghe Sea, the "new IMN" prepared for a "second-stage conflict" in which, having defeated the enemy battle fleet, it would support Army operations to seize and liberate neighboring colonies. During this phase, the emphasis would be placed on maintaining blockades in the Helian Ocean and South Menghe Sea to hold off enemy supplies, a task which would require mobile surface action fleets with high speeds and long endurance.

In light of this reversal in doctrine, Menghean warships laid down after 1932 generally possessed higher speeds and longer operational ranges than their earlier predecessors, especially in the case of cruisers. The IMN also laid down larger numbers of submarines, a category of warship which it had neglected during the last few decades, though its submarine warfare tactics remained dated throughout the Pan-Septentrion War. Other changes were organizational: the Marine Infantry, reduced to a base security force in 1908, were greatly expanded, and their mission shifted to amphibious warfare, a change which also required the construction of new troopships.

Role of aircraft carriers

Like many navies of the time, and unlike the neighboring IDN, the IMN was slow to recognize the power of independent carrier action groups as the center of a modern navy. Based on its own exercises in the 1920s, and its observation of Columbian exercises, it concluded that carrier aircraft were unable to meet the ambitious expectations of their strongest proponents, and that armored battleships would remain the most vital assets for some time. In particular, the Navy believed that flying existing naval aircraft types against existing naval AA guns would result in unacceptably high losses for the attacking force, and that the light payloads of interwar carrier strike aircraft were incapable of inflicting major damage on capital ships with deck armor and torpedo protection. While the Navy did anticipate that carrier aircraft could improve in the coming decades, they also anticipated that anti-air guns would improve at an even greater rate.

Instead, the IMN's interwar planners believed that aircraft carriers were best conceived of as force multipliers for larger capital ship fleets. It built two aircraft carriers of its own, the Menggang and Rogang, one for each side of the South Menghe Sea. Each of these would be assigned to a separate battleship formation, or they could operate together in support of a Combined Fleet. The IMN conceived of the mission of its carrier aviation in the following order of priority:

1. Conduct reconnaissance in support of the fleet, to detect enemy warships and submarines.
2. Intercept hostile reconnaissance aircraft to deny the enemy force information about the disposition of the friendly fleet.
3. Intercept hostile torpedo and bomber aircraft, either ship-based or land-based.
4. Harass enemy forces, especially isolated forces, by means of air attacks.

In 1933 the Navy added a fifth priority, "locate and sink enemy supply, transport, and auxiliary ships," and a sixth, "conduct strikes on inland targets, such as airfields, which are out of the range of surface ships' guns."

In light of this focus, a "typical" Menghean carrier air wing in the early war period was split roughly half and half between single-seat fighters and multi-purpose three-seat aircraft which could be used as level bombers, torpedo bombers, or reconnaissance aircraft. Dive bombers were not introduced until 1938, and even then they only made up a small share of each carrier's air wing.

Once the time came to test this carrier doctrine in the Pan-Septentrion War, the Imperial Menghean Navy was slow to recognize its shortcomings and incorrect assumptions, in part because it did not confront an opposing carrier force until late October 1940 when the Organized States entered the war. The Sylvan navy remained in Maracaibo during the early war, and the small Maverican Navy was easily defeated in initial engagements, leading the IMN to believe that its focus on carrier reconnaissance worked. The Battle of the Portcullia Strait involved one fleet carrier, the HMS Furious, but this was lost to Dayashinese carrier aviation before it could pose a threat. The IMN did learn some lessons by observing reports on the successes of Dayashinese carrier aviation, but it only selectively adapted, modernizing its carrier aircraft and laying down new fleet carriers but never fundamentally rethinking its overall doctrine.

Only in the middle of the war, after repeated confrontations with the Organized States, did Menghean naval planners realize the seriousness of their errors in neglecting carrier warfare.

See also

• Greater Menghean Empire
• Kwon Chong-hoon
• Kim Myŏng-hwan
• Pan-Septentrion War