YŎ-53/05 torpedo
| YŎ-53/05 | |
|---|---|
| Type | Torpedo |
| Place of origin | Menghe |
| Service history | |
| In service | 2006-present |
| Used by | Menghe Polvokia Argentstan Republic of Innominada |
| Production history | |
| Manufacturer | Buksŏng Industries Group |
| Variants | see below |
| Specifications | |
| Weight | 1710 kg |
| Length | 7.65 m |
| Diameter | 533 mm |
| Warhead | PBX |
| Warhead weight | 350 kg |
Detonation mechanism | contact and under-keel fuses |
| Engine | Electric motor with silver-zinc oxide batteries |
Operational range | over 60 km |
| Maximum depth | 800 m |
| Speed | 50 knots (high speed) 30 knots (low speed) |
Guidance system | Active or passive acoustic homing |
Launch platform | Surface ships aircraft HŎ-2N Poksŏl-N HŎ-3 Ryongorŭm |
The YŎ-53/05 is a type of heavyweight torpedo used by the Menghean Navy and other members of the Namhae Front. Originally a licensed copy of Eisenmaat's DM2A4 torpedo, it developed in parallel over the decades that followed, resulting in a number of similar but separate design changes. It is generally considered an "offshoot" design on the DM2 family tree. Major variants include the YŎ-53/05N with extended body, the YŎ-53/11 for use by midget submarines, and the extra-long-range YŎ-53/19, which can be launched from coastal installations but is mainly designed for use in standoff attacks against ships in enemy harbors.
YŎ-53/93
The YŎ-53/93 is torpedo model which immediately preceded the YŎ-53/05 in Menghean service. Derived from Eisenmaat's DM2A3, it was licensed as part of the same deal as the Megi-class submarines. The baseline "G" model is identical to the DM2A3, apart from a guidance wire plug which is compatible with the torpedo-tube socket used by preceding Menghean wire-guided torpedoes. The "N" model which followed it was longer in size to take advantage of Menghean submarines' longer torpedo tubes and magazine spaces. The added length went into an expanded conventional warhead and increased battery space, extending the torpedo's range by approximately 33%.
Description
Menghe obtained a production and development license for the DM2A4 in 2005, as part of a naval modernization program that followed the Ummayan Civil War. Previously, Menghean engineers had been working on a purely domestic torpedo design, but it was inferior in nearly all respects to the DM2A4 and other foreign torpedoes on the market. Dayashina's Type 89 torpedo was also considered as an option, but the DM2A4 was found to exhibit superior range, quieter operation, and better seeker performance in shallow water.
As with the YŎ-53/93, longer torpedo tubes on Menghean submarines - sized for Letnian Type 53 family torpedoes - allowed an extension of the DM2A4's modular design. On the "N" variant, the size of the warhead was increased, to raise the kill probability against a large aircraft carrier or cargo ship. To compensate for the added weight, a single battery module was added to the base design, bringing the total to five. Speed and range are thus roughly comparable between the larger YŎ-53/05N and the DM2A4.
Like the DM2A4 family, the YŎ-53/05 has a U-shaped conformal sonar antenna which gives it a wide field of view, covering over 100 degrees to each side of the direction of travel. This eliminates the need to execute scanning zigzags, which consume additional fuel, reduce speed, and increase noise. The seeker has good performance in shallow water areas with changes in salinity, characteristics that the Menghean Navy considered important for operations in the coastal areas of the South Menghe Sea and the Strait of Portcullia. It is also able to track multiple targets at once, and can distinguish between decoy-generated targets and the target it is already tracking. The conformal sonar antenna also allows for a more streamlined nose, reducing flow noise, cavitation, and drag.
For mid-course guidance, the torpedo relies on information transmitted via a fiber-optic cable in a reinforced sheath. Approximately 60 kilometers of rolled cable are carried in the torpedo and the shipboard wire casket loaded behind it. In addition to saving weight over a metal wire, the fiber-optic cable can achieve high data transmission rates, including transmission of high-quality acoustic readings from the torpedo seeker to the submarine sonar room for target confirmation.
Variants
YŎ-53/05G
The baseline variant. It is a direct licensed copy of the 4-battery DM3A4, save for the socket adapter at the end of the guidance cable. This variant was rushed into service to fill the gap while the "N" variant was being prepared.
YŎ-53/05N
The most common variant, produced from 2009 onward. It was lengthened to take full advantage of Menghean submarines' deeper torpedo tubes. The extra length is devoted to a heavier warhead (350 kg vs. 260 kg) and an extra battery module.
YŎ-53/11
This is a shortened version of the YŎ-53/05, with the number of batteries cut down to two. Some sources also claim that the wire-guidance system was replaced by a mid-course inertial navigation system. It is designed to be used by midget submarines like the Pirami class, which have a limited sonar range and shorter torpedo tubes.
YŎ-53/19
This is a major variant which was introduced in 2019, based on experience from the opening engagements of the Innominadan Crisis. It uses the same basic design as the YŎ-53/05, but adds a sixth and seventh battery module. It also incorporates a guidance system inspired by that of Eisenmaat's SeaHake mod 4 ER, with a satellite datalink antenna on a retractable periscope-like mast. It omits the guidance wire as well, replacing it with an inertial navigation system. The guidance module was modified as well, to incorporate an active blue-green Lidar system for terrain avoidance in shallow water.
Role
Menghean sources state that the YŎ-53/17 is mainly intended for long-range attacks on stationary targets, such as docked ships and bridge towers. The combat center operator programs a multi-leg trajectory into the torpeodo before launch, including the target's dimensional characteristics if available. For the first leg of its trajectory, the torpedo remains underwater, to avoid giving away the submarine's location. Once it is a safe distance away, it ascends, deploys its mast, and takes a brief Constellation SATNAV reading to correct its location and bearing information. It continues toward the destination in a similar guidance pattern, running on inertial navigation with periodic satellite updates. Some analysts speculate that as the torpedo approaches a harbor or other shallow area, the blue-green laser bottom profile could be used for undersea terrain contour matching, though this would require detailed depth surveys of the harbor in question. As it approaches the target, the torpedo switches to its active sonar seeker, and either makes a direct impact or conducts a below-keel detonation.
The YŎ-53/19 has an alternative running mode which allows it to travel continuously with the satellite antenna above the surface, to receive constant course updates via satellite. This allows it to engage moving targets at long ranges, but only if the launch platform has a surfaced satellite datalink as well. This mode is not typically used by submarines, as it requires keeping the satellite communication antenna above the waterline and broadcasting for an extended period of time, but it is used by the JŎB-53/2 system.
Specifications
- Length: 7.8 m
- Mass: 1750 kg
- Range: over 200 km at 30 knots
- Maximum speed: 50 knots
- Warhead: 350 kg PBX
- Guidance:
- Mid-course inertial with satellite updates
- Terminal active acoustic homing
JŎB-53/2
The JŎB-53/2 Ŏbu ("Fisherman") is a land-based launch system for the YŎ-53/19 long-range torpedo. It consists of a wheeled Taekchŏn T512 chassis with two torpedoes in a rear-facing carriage. When on combat alert, the vehicle moves to a prepositioned launch position or existing embankment, parks with the rear facing the sea, and lowers the carriage into the water. The torpedo launches under its own power and runs at a shallow depth with the mast extended to receive constant tracking updates, which are relayed via satellite from the launch platform. The launch platform, in turn, receives updates on the target's movement from another datalinked platform such as a patrol aircraft. At a set distance from the target, the torpedo dives to conceal its antenna and runs toward the target's predicted location on inertial guidance until its passive seeker detects it.
Compared with a land-based anti-ship missile launcher, the Ŏbu system is less flexible in the launch positions it can use, has a longer reaction time, and fires a projectile which takes a much longer time to reach the target. Its main advantage is the lack of anti-torpedo hardkill systems on many enemy warships. The Menghean Navy has acquired a small number of launch batteries, and bases them close to Altagracia and Isla Diamante.