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.

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 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, because it is difficult to determine the situation around them. The submarine crew must understand this and follow the emergence procedure carefully, including

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 pulled behind the tail to increase tracking.

The crew can use active sonar to detect obstacles and warn the risk of a collision.

"There are some conditions that allow short-term proactive sonar operation to detect the surroundings, but combat conditions generally do not support this action. If you generate the signal yourself, there will be

Submarines can also use passive sonar, which does not emit signals but only collects sound waves from the environment.

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.

"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.

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.