Madaesan-class cruiser

File:CA Madaesan 1932.png Madaesan as commissioned, without wartime AA improvements.
Class overview
Name:	Madaesan-class cruiser
Operators:	Greater Menghean Empire
Succeeded by:	Taegisan-class cruiser
Built:	1927-1932
In service:	1932-1945
Planned:	2
Completed:	2
Lost:	1
Retired:	1
General characteristics Madaesan, 1932
Type:	Heavy cruiser
Displacement:	11,850 tonnes standard 12,890 tonnes full load
Length:	181.4 m at waterline 186.1 m overall
Beam:	20.6 m
Draught:	7.14 m (normal) 7.35 m (full load)
Propulsion:	2 steam turbines, 100,000 shp total 8 three-drum boilers 2 shafts
Speed:	32.2 knots
Range:	4,200 nm (7,780 km) at 15 knots
Complement:	784
Armament:	4 × 2 200mm L/50 Type 29 naval gun 4 × 2 100mm L/40 Type 28 AA gun 8 × 12.5mm mg (8×1) 4 × 3 550mm trainable torpedo tube
Aircraft carried:	1 × Donghae Type 32 floatplane
Aviation facilities:	1 × catapult, recovery crane

The Madaesan-class cruisers (Menghean: 마대산급 순양함 / 馬垈山級巡洋艦, Madaesan-gŭb Sunyangham) were a pair of heavy cruisers built in the Greater Menghean Empire during the late 1920s. Conceived of as a response to the first generation of "treaty cruisers" being built in other naval powers, they were designed to withstand 8-inch shells at regular combat ranges, while retaining adequate firepower to defeat armor protection of their foreign counterparts. As such, they were the best-protected of the first generation of treaty cruisers, but also the slowest, with a top speed of 32 knots. They did not surpass the 12,000-ton standard displacement restriction set by the Septentrion Nine-Power Naval Treaty.

Background

Following the indecisive armistice that ended the War of the Sylvan Succession, the leading military powers again embarked on an arms race to build up their naval forces. The Septentrion Nine-Power Naval Treaty, signed in 1923, set a cap on new capital ship construction, but in its initial version it did not apply to warships displacing under 12,000 tonnes. This opened the way for an arms race in heavy cruisers which were designed to make the most of this ceiling. Among the early warships in this category were the Tyrannian County-class, the Sylvan Trento-class, and the Galenic AA-class cruisers. All of these vessels were armed with a main battery of 8-inch (203mm) rifled guns, also a feature of the treaty limits.

The Menghean Navy, led by Navy Minister Pak Dong-ha, responded by commencing design work on a heavy cruiser specifically designed to counter these new designs should they intrude into Menghean waters. In keeping with the Navy's doctrine at the time, these ships were designed to trade range and speed for protection, in anticipation of a defensive war fought not far from Menghe's own coast. As such, all design proposals were required to withstand 8-inch shells from contemporary hostile cruisers at typical combat ranges.

Construction was initially delayed by the Federal Assembly, which refused to allocate funds for such a project on the basis that the modified Hwaju-class battlecruisers - classified under the treaty as "large cruisers" - were already capable of fulfilling such a role. The Navy also experienced delays in the design and development process, in part due to concerns over the protection scheme and the draft of the ships. The government only allocated funds for construction in 1927, after Kwon Chong-hoon came to power in a military coup and stepped up defense spending across the board.

Construction proceeded slowly for a ship of this size, and a number of changes were made while the ships were still on the slipway. These included the addition of air-filled anti-torpedo bulges during construction, a change intended to sit the ships a little higher in the water, improve stability, and make full use of the 12,000-ton displacement limit. Concerns which emerged during construction also filtered over to the design of the Taegisan-class cruisers, which were laid down in 1929. The first two treaty cruisers, Madaesan and Baegaksan, were both commissioned in 1932, behind schedule and over budget, but still very capable for their time.

Design

Armament

The main armament of the Madaesan-class cruisers consisted of eight 200mm L/50 Type 29 naval guns in four two-gun mounts. These used the "G-type" turret design, in contrast to the "N-type" used on the Jinan-class cruisers. Though far from exceptional, the 200mm AP shell fired by these guns could easily penetrate the main belt armor of all contemporary heavy cruiser classes at ranges where the Madaesan class was relatively safe.

The main gun magazines were located in the lowest deck of the ship, to ensure maximum protection from plunging shells. Two hundred complete rounds were carried for each gun, in a mixture of armor-piercing, high-explosive, and illumination rounds, with two bags of powder for each shell. The shell and powder hoists used a bucket-type system with flash protectors that covered the hoist passage for most of the cycle, preventing a gun misfire or turret penetration from igniting an explosion in the magazine. Rate of fire is listed at 3 to 4 rounds per minute, depending on the angle of the gun, as ramming of new ammunition was performed at +5 degrees.

The ships' initial AA armament began with six 100mm L/40 Type 28 anti-aircraft guns in unshielded single mounts, three on each broadside. While not outstanding, this was about average for the time, and in 1937 both ships would be fitted with twin mounts in place of the single ones. Secondary anti-aircraft armament also increased over the course of the ships' lifetimes, from eight 12.5mm machine guns at the beginning of the war to a wide assortment of autocannons at the war's end.

Torpedo armament was relatively heavy, at four triple 550mm traversing mounts, two per broadside. These initially fired the Type 23 torpedo, but by the outbreak of the Pan-Septentrion War they were usually loaded with the Type 23-II, which had a longer range of 11,000 meters at 31 knots. This was still below the expected maximum range at which these ships were intended to fight, and it was in some respects an afterthought; most initial design proposals did not include torpedo tubes. No on-board reloads were carried.

Protection

<imgur thumb="yes" w="300" comment="Cross-section of the Madaesan at her boiler rooms, showing armor thicknesses at various locations. Note that draft markers are for heavier mid-war loadouts.">Qm6BA4V.png</imgur> The Madaesan and Baegaksan were by far the best-protected ships in the first generation of "treaty cruisers," in large part due to the Navy's requirement that they be able to withstand main battery fire from enemy heavy cruisers. Their main armor belt was 150 millimeters thick and angled slightly downward, and beneath it was a secondary belt narrowing from 100 millimeters at the top to 50 millimeters at the base. The turret faces were 200 millimeters thick, and the barbettes 150 millimeters thick. The armored deck consisted of a 50mm layer of hardened armor stacked on top of a 25mm structural backing, totaling 75 millimeters in all. In general, this armor scheme was twice as thick at any location as the armor on their Sylvan counterparts, the Trento-class cruisers, and in some places three times as thick.

Taken together, the components of this armor scheme allowed the Madaesans to withstand a typical interwar 8-inch SAP projectile from ranges of between 15,000 meters, below which it would penetrate the belt, and 25,000 meters, above which it would penetrate the deck. These corresponded to practical combat ranges for warships of the time, and allowed the Madaesan to engage contemporary heavy cruisers with relative impunity. Furthermore, as the ships sat low in the water, the main armor belt barely rose above the waterline at full load, meaning that most 8-inch projectiles striking the ship were unlikely to penetrate the armored citadel.

Equally formidable was the class's underwater torpedo protection. On either side, the boiler and turbine compartments were separated from the outside water first by a 10-millimeter torpedo bulkhead, then oil tanks, and then by anti-torpedo bulges which were added during construction to bring standard displacement just shy of the 12,000-ton limit. Together, this added up to a buffer space averaging 3.5 meters thick over the machinery spaces, consisting of alternating air and liquid filled watertight compartments with the lower portion of the belt armor in between. This layout proved useful in dissipating the explosive force of a nearby torpedo detonation, and containing any lengthwise flooding within the protected spaces. Underneath, the ships had a fairly generous double bottom, which provided protection against mines and seafloor obstacles.

Maneuverability

Needless to say, the impressive armor of the Madaesans came at a cost. As the machinery space had to fit within the confines of a low armor deck and wide anti-torpedo bulkheads, the ships only had room for a 100,000-horsepower powerplant. Combined with the added anti-torpedo bulges on either side of the already wide hull, this reduced their top speed to around 32 knots at a normal combat load.

The naval planners of the time, headed by Pak Dong-ha, considered this an acceptable tradeoff, as they anticipated using their heavy cruisers in a defensive fashion. Even before Kwon Chong-hoon purged the Navy of its existing upper staff, however, critics within the IMN argued that the slow speed of the Madaesan-class hamstrung its ability to fight enemy heavy cruisers effectively, as the opponent could simply accelerate to full steam and outrun its pursuer. This was even more true for enemy light cruisers. In the heavy cruiser classes that followed - the Taegisans and particularly the Hasŏlsans - the IMN would attempt to correct for this problem by trading away some protection for greater speed.

Operational history

<imgur thumb="yes" w="400" comment="Lengthwise cross-section of the Madaesan (1932 layout) showing her internal systems.">nNtcs1X.png</imgur> The cruisers Madaesan and Baegaksan were both commissioned in 1932, three years before the outbreak of war with Sylva. Both took part in Operation Chŏng-Chŏn, the campaign to take Altagracia, where they bombarded shore positions in support of the Army's advance. Shortly afterward, on August 29th, Baegaksan demonstrated the value of the ships' heavy underwater protection when she sustained two torpedo hits from Sylvan bombers but did not experience any leakage into her vital spaces. The conditions were somewhat ideal - both torpedoes hit at the widest section of the anti-torpedo bulge, and they were WSS-vintage 18-inch torpedoes with relatively light warheads, but the incident led to high confidence in the IMN about Menghean warships' torpedo protection.

The cruiser Madaesan, by contrast, had a career crossed with ill luck. During a demonstration in January 1933, a torpedo from her forward starboard tube set fired by accident, narrowly missing the base of the pyramid mast as it skidded along the deck. As the fuse failed to arm properly, the warhead did not detonate, but the captain had to withdraw from the exercises and evacuate the ship while an ordnance disposal team came on board.

Another incident took place in September 1936, when Madaesan was undergoing refueling while at anchor in the captured harbor at Nueva Meridia. As she pulled away from the tanker alongside her, her stern brushed alongside, and her outermost starboard-side propeller cut a series of holes in the hapless vessel, spilling oil into the harbor. Fearful of the public relations consequences at home, the Imperial Menghean Navy tried to cover up the incident, blaming it on colonialist saboteurs; thus, little surviving information is available to assess what went wrong prior to the collision and why the braces over the propellers failed to stop it.

Madaesan encountered problems again two years later, during the Evacuation of Santiago. After Rear-Admiral Choe Jŏng-nam belatedly identified an unexpected formation of Sylvan battleships on the horizon, he ordered his ships to immediately turn around, setting off a chaotic scramble to change formation. In the midst of the confusion, Madaesan collided with the light cruiser Ichŏn, and the two scraped alongside each other as the Ichŏn struggled to pull away. The Madaesan suffered only minor damage during this incident, as her torpedo protection absorbed the force of the collision and prevented water from entering vital spaces, but her lighter counterpart was not so lucky. With heavy flooding in all of her boiler spaces, the Ichŏn quickly lost power and began to sink, prompting her commander to issue the order to abandon ship. During the same engagement, Baegaksan was more fortunate; a Sylvan large-caliber shell, possibly fired by a battleship, struck her above her armor belt at a shallow angle and passed clean through the ship, bouncing off the 75-millimeter armor deck without causing any damage to vital systems.

After undergoing repairs in late 1938, the Madaesan and Baegaksan spent the height of the war operating along the coast of Maverica, where their short range and low speed were less of a problem. They came under aerial attack at the First Battle of Swartzburg, though neither was seriously damaged. At Baumburg they provided coastal bombardment during the attempted Menghean breakout, though they were ultimately driven off after running out of high-explosive shells.

The cruisers' final mission took place in February 1944, as they escorted a large convoy of Menghean troop transports out of Khalistan. Columbian dive-bombers attempting to stop the evacuation struck the Baegaksan on her quarterdeck, damaging her steering motors and causing her to veer sharply to starboard. Madaesan, which was sailing in formation behind her, made a shallow turn to starboard, for reasons that remain disputed; some accounts suggest that she mistook Baegaksan's out-of-control turn for a change in formation, while others hold that her captain's orders were garbled in transmission to the backup navigation space inside the ship, leading the helmsman to turn to starboard rather than port.

Whatever the cause, Madaesan rammed prow-first into the side of the Baegaksan just aft of her #4 turret. A large portion of the latter ship's stern was sheared off, while Madaesan herself saw her bow crumple inward under the high-speed impact. With two of her propeller shafts warped by the collision, Baegaksan was unable to move under her own power, and water had flooded into her aft magazines. After coming around, Madaesan attempted to tow her to port, but the former ship's captain decided it was safer to scuttle the immobilized ship, as the entire formation was traveling in submarine-infested waters and the main priority was to keep pace with the troopships.

Madaesan herself was able to sail to Kusadasi under her own power, where port engineers patched the worst damage in her bow. She then sailed to Haeju for more comprehensive reconstruction, but remained in drydock until the end of the war, as the Navy was too weak to attempt a major confrontation and steel and fuel were needed for the Army's defense. She sustained additional damage during the atomic bombing of Haeju, which knocked her off of her supporting struts and seared the starboard side of her superstructure. After Menghe's surrender, she was lightly decontaminated and then broken up for scrap.

On closer examination of ships' logs and other records, some historians have come to the defense of the ill-fated Madaesan, noting that in each of its collision incidents the major contributing errors were made by the other ship, not the cruiser herself. She also proved herself a capable ship in surface-to-surface and surface-to-air combat, with her low, well-armored citadel providing good protection against enemy fire and her well-padded sides stopping torpedo hits on her final mission. Nevertheless, her reputation for accidents has come to outshine her combat record, and after she returned to port for repairs in 1944, some Menghean engineers and sailors regarded her as a "cursed ship."

See also

• Taean-class cruiser
• Taegisan-class cruiser