The Bermuda Triangle. The telephone exchange is going crazy, random calls on the ship

On every ship, there are many different episodes with systems and equipment that can be explained and that defy any logic. But with years of practice, you understand that everything that happens on the ship with systems and equipment can be analyzed from a scientific point of view. Even if some outright "miracles" occur that do not fit in the head.

In this short story, I want to tell a story that happened with the telephone exchange on the ship. One fine day, random calls began to come to the cabins of the crew members at night, when people were sleeping. This continued for about two days. At first, they did not attach any importance to this, since only two people complained and decided that someone simply mixed up the cabin number when dialing.

The next day, calls began to the engine room. At the same time, there was just noise in the receiver. By a "lucky" coincidence, the ship was passing the Bermuda Triangle at the same time, and it is easy to imagine the mood of the crew when such anomalies occur.

In this situation, my task, as a ship's electrical engineer, was to find out the cause of this problem and fix it. I immediately thought that there was a problem with the automatic telephone station and it was simply going crazy. I disassembled the entire telephone station, check all possible contact groups, but still found nothing.

Rebooting the station did not help. I also checked the ship's public address system, since it is an adjacent system with the telephone station. Having already despaired, I decided that it was necessary to change the PLC board.

The random calls began at the time when the pitching increased and they were irregular, which complicated the search.

At some point, I noticed the socket for connecting the bunker telephone on the left side of the main deck. It turned out that the socket was flooded with water, which during strong pitching got on the contacts (plus and minus 24V DC). Thus, the resistance and voltage of the circuit changed, and these random calls to the cabins and the engine room occurred. At the other end of the handset, the sound of the sea was heard :)

Water in the socket

Bunkering telephone socket

Terminal block and electrical tape in water

Bunkering telephone socket (on the cover on the back side you can see the water level that was inside)

At the same time, the last time the ship was at the berth, bunkering, the bunker telephone was connected to this socket and the calls in the future were exactly the same as during bunkering operations (to the same places).

After replacing the socket, the calls stopped and the telephone station worked fine. These are the kinds of incidents that happen on a ship, and once again we can conclude that any breakdown should be approached first from the simple side, i.e. check the simple elements that can break, and then deal with more complex parts of the equipment.

Ship telephone station: MARINE TYPE TELEPHONE SYSTEM. NIPPON HAKUYO electronics, ltd.