M-boat

M-boat was a designation which the Allied powers applied to a family of torpedo-armed fast attack craft operated by the Greater Menghean Empire during the Pan-Septentrion War. In Menghe, these craft were known as "fast torpedo boats" (고속 어뢰정 / 高速魚雷艇, gosok ŏroejŏng).

The Allied name encompassed a variety of different ship types, from the 18-meter Type 24 class to the 35-meter Type 38 class. The armament of these types varied, with the heaviest ones incorporating autocannons for anti-aircraft and surface-to-surface operations. Some craft were also modified to carry supplies or small special forces teams in place of torpedoes, and others were converted to fast gunboats (고속 포정 / 高速砲艇, gosok pojŏng).

Apart from this variation in size and armament, they were broadly similar to the Ostlandian E-boat, the Columbian PT boat, and the Tyrannian Motor Torpedo Boat, and specialized in coastal operations and short-distance raids, including raids against enemy harbors.

History

During the Three States Period in the late 19th century, all major factions struggling for power made use of steam-powered torpedo boats, first by importing them from abroad and later by producing their own designs. These proved highly effective in coastal combat, especially around the rocky shores of Ryŏnggyŏng Province where most Sinŭi-Namyang naval engagements took place. After Menghe's reunification in 1900, the new Federal government saw light torpedo craft as an important defensive weapon against larger Casaterran navies, as they could rapidly sortie from port and engage heavier capital ships.

Initially, the Menghean designation "torpedo craft" (어뢰함 / 魚雷艦, ŏroeham) applied to vessels slightly smaller than a destroyer, generally with comparable torpedo armament and weaker gun armament. In 1924, with the delivery of the first Type 24 vessel to active units, the Imperial Menghean Navy created a separate category of "fast torpedo boats" (고속 어뢰정 / 高速魚雷艇, gosok ŏroejŏng) which it applied to vessels with a lighter tonnage and a shorter operational range. These craft later became known in the West as "M-boats."

The first "M-boats," the Type 24 class, were derived from Tyrannian naval technology, as Tyran had emerged as a potential partner of Menghe during the War of the Sylvan Succession. After Kwon Chong-hoon's military coup, however, Menghe turned to Ostland for military assistance. The Type 33 class torpedo boat was developed with the help of Ostlandian engineers who had worked on early E-boat projects, and displayed a number of Ostlandian influences, including the placement of the torpedo tubes. The engines were also of foreign design. The Type 38, which came next, also drew many features from Ostlandian E-boats, though there is no documentation of foreign naval architects' involvement in its construction.

During the Pan-Septentrion War, Menghean "M-boats" mainly provided support for coastal operations, intercepting enemy supply ships and transports. They were most active in Innominada, Khalistan, and Maverica. There is no record of an M-boat sinking an Allied warship, in part because fleets traveling in formation could mass enough secondary battery fire to drive attackers away, but these craft did have a significant impact on Allied and especially Tyrannian shipping early in the war. Menghean commanders also found that they could provide effective coastal fire support in lightly defended areas, owing to their shallow draft, autocannon armament, and high speed to evade defenders.

Major types

Type 24

<imgur thumb="yes" w="400" comment="Three major variants of the Type 24 motor torpedo boat.">6Qnay6p.png</imgur> Developed in the aftermath of the War of the Sylvan Succession, the Type 24 motor torpedo boat was derived from the Tyrannian 55-foot CMB, which had demonstrated its capabilities in that conflict. The Type 24 was powered by a single petrol engine converted from aircraft use, and in its initial configuration it could reach a top speed of 34 knots; this increased to 48 knots on the Type 24-II, which used a newer, more powerful engine and could carry slightly longer torpedoes.

As on the 55-foot CMB, the main armament consisted of two 45-centimeter torpedoes, which were stored side-by-side in a recessed compartment on the aft deck. To attack, the Type 24 would point the bow at the target, then propel the torpedoes aft using compressed-air charges hooked up to a bell-shaped cover on the nose. A wire tripped the torpedo engines as they fell off the stern, and the crew had a short period in which to execute a U-turn before the torpedoes overtook their craft from behind. As with the 55-foor CMB and the FSR's G-5, there is no recorded instance of a Type 24 being struck by its own torpedo, though there was one night engagement off the coast of Khalistan in which two Type 24s collided during an attack in formation.

From the start, the Type 24 was designed for versatility, and its rear compartment could be loaded with seven mines or ten depth charges in place of the two torpedoes. During the early years of the Pan-Septentrion War, Menghean forces found that it was possible to fit a ten-man squad with equipment into the torpedo compartment and use the Type 24 as a landing craft, a role where its high speed, shallow draft, and low profile made it highly effective at inserting reconnaissance units behind enemy lines. The Type 24-III variant, introduced in 1936, added railings and seats in the passenger compartment, a second 12.5mm machine gun, and a reinforced bow for amphibious operations, but lost the ability to fire torpedoes.

Specifications (Type 24-II)

• Length: 17.4 meters (waterline, excluding rudder), 19.7 meters (overall, including rear hoists)
• Beam: 3.4 meters
• Draft: 0.96 meters (full load)
• Power: 1200 hp (895 kW) total, 2 shafts
• Speed: 48 knots
• Crew: 5
• Armament:

• 2 × 550mm torpedoes in rear cradle
• 1 × 12.5mm air-cooled machine gun (Type 31)

Type 33

<imgur thumb="yes" w="400" comment="Three major variants of the Type 33 motor torpedo boat. Type 33-III, not pictured, carried single 20mm autocannons in place of the two dual 12.5mm HMGs.">pNYEpHw.png</imgur> The Type 33 was the most widely produced Menghean light torpedo craft of the Pan-Septentrion War, and it is the model that first led Tyran to coin the "M-boat" designation. It originated from an Ostlandian design, and bore some influences from the larger S-100 "E-boat" of the Kriegsmarine. Its main armament consisted of two forward-facing torpedo tubes, with no reloads carried on board, but it was also armed for anti-submarine warfare and minelaying operations.

During the war, the Type 33 underwent a number of modifications and improvements. The Type 33-II, introduced in 1941, carried a single manually aimed 37.5mm Type 38 anti-aircraft gun on the aft deck, a change introduced in response to engagements with similarly up-armed PT boats in Columbian and Maverican service. This change required the removal of the depth charge racks, which were found to be of limited use in combat operations, though the reduction in capability meant that most Type 33s would retain the Type 33-I configuration up to the war's end. A smaller change, the Type 33-III, replaced both dual machine guns with 20mm autocannons, while retaining the depth charge racks and minelaying rails.

The final variant in the Type 33 family, designated Type 33-IV, was built as a dedicated gunboat, with the torpedo tubes removed and replaced with an additional 20mm pintle-mounted autocannon on each side. A dedicated fire-control pedestal for the 37.5mm autocannon was also installed. This type was mainly used as a coastal patrol vessel or light escort, and was designed to fend off aircraft and other light torpedo craft.

A wide variety of field modifications also existed, carrying foredeck- or aft-mounted 37mm or 50mm anti-tank guns, 75mm mortars, or 2-4 additional machine guns in place of the torpedo tubes. These configurations were mainly carried out in the field by crews using scavenged equipment, and did not receive formal designations of their own. Variants with guns on the foredeck had poor seaworthiness, and were limited to low-speed coastal and river operations for the safety of the forward gun crew.

Specifications (Type 33-I)

• Length: 24.1 meters (waterline), 25.2 meters (overall)
• Beam: 6.1 meters
• Draft: 1.83 meters (full load)
• Powerplant: 3 60-L displacement petrol engines
• Power: 3000 hp (2237 kW)
• Speed: 42 knots
• Crew: 2 officers, 12 men
• Armament:

• 2 × 550mm torpedo tubes (no reloads)
• 2 × 2 12.5mm water-cooled machine gun

Type 38

<imgur thumb="yes" w="400" comment="Two major variants of the Type 38 motor torpedo boat.">J0YYXL9.png</imgur> Developed during the conflict with Sylva, the Type 38 was intended to improve on the Type 33's characteristics through increased range and seaworthiness, allowing it to venture further into the open ocean or patrol further along the coast. For this purpose, it used two diesel engines rather than the prior generation of petrol engines, and carried more fuel and supplies onboard.

Along with the increase in size and range, the new ships also received an increase in armament. While they carried only two forward-facing torpedo tubes, they also carried two additional torpedo reloads amidships. The initial defensive armament consisted of three dual 12.5mm Type 31 machine guns in water-cooled mounts. On the Type 38-II, these were replaced with two 20mm cannons, one of them in a sealed, powered mount, and a Type 38 anti-aircraft gun. A modest draft allowed the type to close with the shore or sail up major rivers and use its deck guns for coastal fire support.

Two depth charge racks at the rear offered some anti-submarine capability, though even in its final iterations the Type 38 lacked sonar equipment and had to rely on signals from nearby destroyers or visual indicators of a submarine's location. Late in the war, the depth charge racks were often removed or left empty.

Specifications (Type 38-II)

• Length: 34.6 meters (waterline), 35.4 meters (overall)
• Beam: 5.08 meters
• Draft: 1.92 meters (full load)
• Powerplant: 2 diesel engines
• Power: 4000 hp (2983 kW), 2 shafts
• Speed: 42 knots
• Crew: 28
• Armament:

• 2 × 550mm torpedo tubes (2 reloads)
• 2 × 20mm Type 41 autocannon (1 in enclosed powered mount)
• 1 × Type 38 37.5mm anti-aircraft gun

Post-war usage

After Menghe's surrender, the Allied powers ordered that all surviving M-boats be scrapped as part of a comprehensive disarmament program. Most surviving M-boats met this fate, as the Allies showed little interest in retaining survivors for testing and analysis.

A small number of M-boats, eight in all according to most sources but nine according to some, were anchored in Azbekistan when Menghe surrendered. Retreating Menghean forces turned them over to Azbekistani militia, who continued to use them against Tyrannian forces attempting to restore control over what was then Tyrannian East Khalistan. Most of these vessels were lost in battle or captured, and none of them ever engaged a Tyrannian warship, although one did sink a transport vessel bringing in supplies. After Azbekistan gained independence, two aging M-boats were still serviceable and remained in use with the Azbekistani Navy; both were retired in the 1970s.

Today, there is only one surviving M-boat, a Type 38 model designated GŎ-152. It was captured by Tyrannian forces in 1940 during the Acheron campaign, to insert commandos and spies behind Menghean lines. Throughout the Khalistan campaign, the Menghean Army never discovered that GŎ-152 was in Tyrannian hands; the Navy assumed the craft was lost and struck it from the official register, but never passed this on to Army coastal patrols, who spotted the GŎ-152 on several occasions but did not suspect anything out of the ordinary. GŎ-152 survived to the end of the war, and was purchased by a private collector in 1946; after a careful restoration in 1998, it now resides at the Hadaway Naval Museum.

See also

• Jindo-class destroyer