Early model of the domestic S1100 submarine, note that it still uses a shell rudder
According to the "the drive" website, a new generation of domestic conventional submarines is undergoing sea trials. The submarine may have adopted a single-hull structure. It marks the shift of domestic submarines from double-hull to single-hull, which is a historic transformation of domestic submarines.
After analyzing the relevant pictures, the submarine is considered to be about 50 meters (160 feet) long. The control tower shell adopts trapezoidal shape, which is similar in appearance to the German 212 submarine and has good stealth noise reduction performance. In addition, it also uses a bow rudder instead of the hull rudder currently used by domestic conventional submarines. Generally speaking, the bow rudder efficiency is higher, but it is difficult to berth out of the voyage, it needs to be retracted, and the structure is complex. It also generates noise that affects the bow sonar detection capabilities. The shell rudder is less efficient, but it is far away from the sonar, does not need to be retracted, and the structure is simple. Of course, it needs to increase the volume and weight of the enclosure, which will affect the hydrodynamic power of the submarine and occupy the valuable space in the enclosure. We submarine designers should have taken into account all aspects and adopted a bow rudder on a new type of domestic conventional submarine.
The S1100 submarine, which is being tested, has been changed to a bow rudder
From the relevant characteristics, this submarine is reminiscent of the domestic new generation of export-type conventional submarines launched by CSIC - S 1100. According to the information provided by CSIC, the S 1100 has an underwater displacement of 1100 tons and a length of 60 meters. The biggest feature of the S 1100 series submarine is the use of a single-hull structure, which is also the first domestic submarine to adopt a single-hull hull. Although the S 1100 is an export submarine, its appearance shows that we have mastered the single-hull technology of submarines, paving the way for the transformation of domestic submarines, which is of far-reaching significance.
Domestic submarines were trained in the Soviet Union, and Soviet-made submarines traditionally used double-hulls. The advantages of the double-hull are large reserve buoyancy, strong wartime survivability, and suitable for activities in polar waters. However, the cost is also very large, the volume and tonnage increase, the exposure area increases, and the underwater maneuverability becomes worse. As an example, Russia's latest North Wind God class strategic missile submarine has a water displacement of 15,000 tons, which is lower than that of the Ohio-class strategic missile submarines of the United States, which has a water displacement of 17,000 tons. However, the former uses a double-hull hull, the latter is a single-hull hull, after diving, the North Wind God class underwater displacement is close to 25,000 tons, and the Ohio class has less than 20,000 tons. The former is 5,000 tons more than the latter, almost the full load displacement of a destroyer.
The North Wind God class strategic missile nuclear submarine has less underwater displacement than the Ohio class
The underwater displacement is much larger than the latter
Modern submarines have extremely high requirements for quietness, and submarines need to use various noise reduction measures, such as large floating raft vibration damping bases. All these put forward higher requirements for the internal space of submarines. Under the same conditions, the double-hull space is smaller than that of the single-hull hull. Alternatively, the double-hull volume and tonnage are significantly higher than those of the single-hull hull. The underwater displacement of Russia's AK-class attack nuclear submarines has reached 10,000 tons, compared with only about 7,000 tons in the Los Angeles class of the United States. Russia's latest Yasen-class attack nuclear submarines have adopted a single-hull, but the underwater displacement still reached 14,000 tons, compared with only 8,000 tons of Virginia-class attack nuclear submarines in the United States at the same time.
The Yasen class part adopts a single-hull hull structure
In fact, the Soviet Union also realized that the double-hull was becoming more and more limited, and the fourth generation of submarines began to transform into single-hulled submarines. The fourth generation of Soviet conventional submarines- the Lada class adopts a single-hull hull, which is also the first Type of Soviet-made submarine with a single-hull hull, while the Yasen class part adopts a single-hull hull structure. It is speculated that Russia's next generation of attack nuclear submarines and strategic missile nuclear submarines may also turn to single-hull hulls.
The Lada class is already a single-hull submarine
Domestic submarines are also facing the problem of a sharp increase in underwater displacement. With the increase of silent performance, the underwater displacement of the new generation of domestic submarines is also increasing rapidly. The domestic 039A AIP submarine has an underwater displacement of more than 4,000 tons. This figure is almost twice that of Western AIP submarines, such as the French Scorpio-class submarine AIP type with an underwater displacement of only 2,000 tons. Under the same conditions, the greater the displacement, the higher the price and cost, and the lower the underwater maneuverability. In order to export to the outside world, we had to shrink the Type 039A submarine, but its underwater displacement was still around 2300 tons. On the other hand, the shrinking of the submarine will definitely compress the internal space, which will also adversely affect the muting measures. In this case, CSIC developed the S 1100 submarine, which uses a single-hull hull. The internal space is guaranteed with reduced discharge, providing a material basis for silent measures.
The outside world speculates that domestic submarines will be transformed into single-hull hulls in the future, and not only conventional submarines but also nuclear submarines will use single-hull hulls to further improve combat capabilities.