WHAT IS A LEAKY CABLE?

Slit cable is a communication system used in environments such as tunnels and underground mines. In this system, which is prepared by taking into account the Layman principles, the signal is broadcast to the outside environment at the desired points with the slits created on the cable designed not to spread the signal on it to the outside.

WORKING PRINCIPLES

A slot cable is a coaxial cable that passes through tunnels etc. This cable acts as an antenna that transmits radio waves or receives signals through slits on the cable. The slots on the cable are provided with gaps formed on the outer metal armor that prevents the wave from propagating outward. These gaps are used for both transmitting and receiving. Because of these slits in the cable, signal amplification devices are needed every 350-500 meters along the line to keep the signal detectable and meaningful. The transmitted signal is usually received by mobile devices. Communication between mobile devices on a vehicle such as an employee or locomotive, the rest of the system and the outside environment is possible through this cable system acting as an antenna. Since there is only one antenna in the system, there is no roaming problem in mobile systems. Since this system is both a transmitter and a receiver, two-way communication is possible. Although it is not possible to pass through solid objects due to the characteristics of the signal used (usually UHF and VHF), this system makes bidirectional communication possible along the line.

These cables are used in mines, especially for voice communication. In this way, it is ensured that all employees in an area are in constant communication. Likewise, this technology is also utilized in underground rail systems and tunnel crossings. Especially in long line railways where radio communication is used, the communication between the engineer and other components is interrupted inside the tunnel. With a transceiver installed at the tunnel entrance, outdoor signals are received and broadcast into the tunnel via a slotted cable. Thus, uninterrupted communication is provided along the line. Especially in railways, there may be no energy systems in the tunnel areas. If the line is electrified, the necessary energy can be provided from the catenary. If the line is not electric but diesel, then the required energy can be provided by solar energy etc. systems. Battery systems are needed for the continuity of energy. In such applications, energy efficiency becomes a little more important. Although generators are also used for these systems, continuous fuel supply increases operating costs and makes the application difficult.