Bŏdŭl-class gunboat

File:PG Bodul 1935.png The Bŏdŭl as she appeared prior to the outbreak of the war and during operations off Innominada.
Class overview
Name:	Bŏdŭl-class gunboat
Operators:	Greater Menghean Empire
Built:	1932-1937
In service:	1934-1945
Planned:	16
Completed:	12
Cancelled:	4
Lost:	10
Retired:	2
General characteristics Bŏdŭl, 1934
Type:	Gunboat
Displacement:	2,000 tonnes standard
Length:	104.5 m at waterline 105.8 m overall
Beam:	12.42 m
Draught:	3.96 m (normal) 4.27 m (full load)
Propulsion:	2 steam turbines, 6,400 shp total 2 oil-fueled boilers 2 shafts
Speed:	20 knots
Range:	2,000 nm (3,700 km) at 10 knots
Complement:	289
Armament:	2 × 2 130mm L/55 Type 32 naval gun 4 × 1 100mm L/44 Type 29 high-angle gun 6 × 12.5mm machine gun (4×1, 1×2)

The Bŏdŭl-class gunboats (Menghean: 버들급 포함 / 버들級砲艦, Bŏdŭl-gŭb poham) were a group of twelve gunboats produced in the Greater Menghean Empire shortly before the Pan-Septentrion War. They were designed to exploit a provision in the Septentrion Nine-Power Naval Treaty by maximizing the combat capabilities of a 2,000-tonne low-speed surface combatant. Originally designed for coastal operations, they were soon expanded to take on anti-submarine and anti-aircraft roles, though they never excelled in either. New construction of the Bŏdŭl-class ended in 1935 to free up small slipways for destroyers and escort ships.

Background

While the original 1923 draft of the Septentrion Nine-Power Naval Treaty only applied to capital ships displacing over 12,000 tons, the "cruiser amendment" added in 1930 placed new restrictions on cruisers, destroyers, and submarines, further restricting the space for new construction. Broadly speaking, the new limits applied to all ships displacing over 600 tons. Yet a special clause added an exemption for ships displacing 600 to 2,000 tons, if they met the following conditions:

• No guns exceeding 6.1 inches (155mm) in caliber;
• No more than four guns exceeding 4.1 inches (105mm) in caliber;
• No torpedoes, or provision for torpedo tubes; and
• A top speed not exceeding 20 knots.

Eager for ways to evade Menghe's relatively low tonnage restrictions and balance out larger naval powers, the Imperial Menghean Navy promptly opened a design competition to produce a gunboat which would make the most of these restrictions. While the clause was first included so that colonial powers would not have to count corvettes and avisos toward their destroyer tonnage, Menghe, which lacked overseas colonies, would use it to produce short-ranged but well-protected ships to help defend its coast against light vessels and submarines.

The Navy considered a range of submitted proposals over the course of the next two years, eventually beginning construction on a ship in 1932. One of the problems they faced during this process was the steady advance of mission creep: while the ships were originally intended as specialized coastal gunboats designed to fend off destroyers and bombard shore targets, the Navy added requirements that they be able to provide anti-aircraft cover for landing ships and conduct open-water anti-submarine patrols.

Design

The main armament of the Bŏdŭl-class consisted of four 130mm guns in two twin turrets, and was actually below the maximum caliber restrictions of the 1930 amendment. The Navy initially considered using 150mm L/50 guns of the same type introduced for the Taean-class cruiser, but concluded that the 130mm L/55 Type 32 naval gun had comparable range and penetration to the existing lower-velocity 150mm gun, and offered a much faster rate of fire: 10 rounds per gun per minute with a fresh crew, rather than 6. This was due to the use of single-piece ammunition and a sliding-block breech. As the gunboats were mainly expected to face destroyers, torpedo boats, and surfaced submarines, this tradeoff was considered worthwhile, even though it did not involve the maximum allowable gun caliber.

As a sort of "secondary battery," the ships also carried four 100mm L/40 Type 29 anti-aircraft guns, as guns with a caliber of less than 105mm were not limited on ships of this size. While mediocre by mid-war standards, this was identical to the flak armament of the Taean-class cruisers as they were originally built, and fairly potent by the standards of the time. The 130mm guns could also fire timed-fuse HE shells against aircraft, but as the turrets could only elevate to 45 degrees, they were of limited use against high-flying or maneuvering aircraft, especially dive bombers. Also mounted were six 12.5mm machine guns in four single mounts and one twin.

As the treaty did not specifically say whether or not ships in this category could carry armor, the Imperial Menghean Navy interpreted armor as unrestricted, and built the ships with a 75 to 100mm belt that covered the boilers and turbines. Additional 75mm armor boxes covered the magazines for the forward and aft turrets. Deck armor over the citadel was 25 millimeters thick. All in all, the Bŏdŭl-class gunboats had comparable protection to many contemporary light cruisers, allowing them to engage enemy destroyers with relative safety. Torpedo protection, of course, was nonexistent, to be expected for such a small ship.

Operational history

At the outset of the Pan-Septentrion War, the Bŏdŭls were primarily used in their intended role as coastal combatants, supporting the Imperial Menghean Army's offensive along the coast of Innominada and later the early landings on Khalistan. Because the Sylvan Flota Oriental withdrew to Maracaibo for the first few years of the war, they did not see much surface action, and were mainly used for coastal bombardment. The Baekham, which was struck by coastal defense guns during the initial attack on Altagracia, has the dubious honor of being the first Menghean warship sunk during the Pan-Septentrion War.

After 1938, the Bŏdŭl-class gunboats played a supporting role in the advance into Maverica, but as one of the few Menghean ship classes with sonar already installed they were increasingly pressed into service as convoy escorts. Slow, large, and equipped with old sonar, they were tempting targets for Allied submarine commanders, and only two survived the war.

Classification

When originally ordered, the Bŏdŭl-class vessels did not fit neatly into the Imperial Menghean Navy's classification and naming system for warships. Accordingly, the Navy revived the classification of gunboats (Poham) to accommodate them, even though they were much larger than earlier gunboat classes. In 1942 they were re-designated Haebangham, a term borrowed from the Dayashinese Kaibokan, and placed in this category alongside other gun-armed anti-submarine ships.

As the "gunboat" classification had been out of use for some time prior to the Bŏdŭls' ordering, the Navy named them after plants, in keeping with naming conventions for earlier gunboats. The plant name series was also used for Menghean torpedo boats during this period, but the Bŏdŭls were considered a separate type of ship, and they displaced nearly three times as much as the largest pre-war torpedo boats.

Ships in the class

Name	Meaning	Laid down	Commissioned	Fate
Bŏdŭl	Willow	1932	1934	Sunk by Maverican coastal gunfire in 1938.
Chŭngchŭngnamu	Dogwood	1932	1934	Torpedoed by a Columbian submarine in 1945.
Baekham	Lily	1933	1934	Sunk by Sylvan coastal guns during the attack on Altagracia, 1935.
Jangmi	Rose	1933	1934	Torpedoed by a Columbian submarine in 1942.
Haebaragi	Sunflower	1933	1935	Surrendered in 1945; scrapped in 1946.
Sonamu	Pine	1933	1935	In drydock for repairs at the war's end. Scrapped in 1947.
Goryang	Sorghum	1934	1935	Torpedoed by a Tyrannian submarine in 1940.
Daemaek	Barley	1934	1935	Torpedoed by a Columbian submarine in 1945.
Dwaejipul	Ragweed	1934	1936	Sunk by Maverican dive bombers in 1940.
Mokhwa	Cotton	1934	1936	Torpedoed by a Columbian submarine in 1944.
Yuhongcho	Cypress vine	1935	1936	Sunk by gunfire from Tyrannian cruisers in 1940.
Bbangnamu	Mulberry tree	1935	1937	Torpedoed by a Tyrannian destroyer in 1940.

See also

• Battle of the Portcullia Strait
• Type 17 rifle