The JS Soryu submarine carries a variety of modern sensors, but cannot warn and prevent a bad collision with the Ocean Artemis cargo ship.
“The submarine was on a regular training mission and detected the cargo ship through the periscope while emerging, but could not dodge it in time. The communication equipment on the submarine was damaged, causing the crew to lose. More than 3 hours moving to a place with telephone waves to report, “Japan’s Defense Minister Nobuo Kishi said on February 8, referring to the JS Soryu submarine collision with the cargo ship Ocean Artemis off the coast. the south of this country.
The incident resulted in JS Soryu’s right wing rupture, a part of the superstructure was dented and the submarine had to move in a floating state to return to the base. The submarine’s command tower communications equipment was also damaged after the impact.
The cause of the collision has not been determined, but experts say that the incident once again shows that the danger is always present in submarine operations.
“Submarines are most susceptible to problems when lifting periscopes out of the water, as it is difficult to determine the surrounding situation. The submarine crew must understand this and follow the emergence procedure carefully, including including safety confirmation by sonar navigation system “, Professor Ito Toshiyuki, former deputy admiral of the Japan Maritime Self-Defense Force, commented.
Soyru-class submarines are equipped with a series of sensors, the main one being the Hughes / Oki ZQQ-7 sonar complex, with a sonar in the nose, four sonar flanks and a sonar pulling behind the tail to increase tracking. Besides, there is an electronic optical periscope and the ZPS-6F airborne perimeter radar for water and aircraft targets.
The crew can use active sonar to detect obstacles and warn the risk of a collision. However, they are rarely activated in combat scenarios, as sonar actively emits acoustic signals that can strike submarines, surface ships, and enemy submarine hunting aircraft.
“There are some conditions that allow short-term proactive sonar operation to detect the surroundings, but the combat conditions generally do not support this action. If you generate the signal yourself, there will definitely be. who discovered you, “said former British submarine officer Jeff Tall.
Submarines can also use passive sonar, which does not emit signals but only collects sound waves from the environment. It provides less information and is less accurate than active sonar, but fully capable of detecting a large cargo ship like the Ocean Artemis.
During the dive, the submarine often relies on an inertial positioning system to provide accurate location data, but it only aids in overcoming fixed obstacles. This system also needs to be constantly calibrated to ensure accuracy, as well as heavily dependent on the seabed map.
“Rising to the surface is one of the most dangerous processes a submarine has to go through. Before doing this, the crew must route all previously discovered objects, including cargo ships. civilian and battleship “, military expert Thomas Newdick commented.
It is not clear why the submarine operator JS Soryu only detected the Ocean Artemis cargo ship just before the collision, which prevented them from applying maneuverable measures to evade. “If the sensing system was working properly, there might be a problem with the crew’s qualifications or their coordination ability,” commented former Vice Admiral Toshiyuki.
Vu Anh (According to the Drive)