Railroad and Transit Products

Tunnel Radio understands the needs of railroads. Since 1992, we have constructed over 500 miles of rail tunnel wireless systems. Continuous clear coverage, system reliability, and customer service come with the Tunnel Radio package. Our UHF Tunnel Radio Link® distributed power technology and the VHF Tunnel Voice® radio communication systems are operating throughout the United States in some of the longest tunnels in America.
Tunnel Voice® (also known as FD-4®) is the VHF member of Tunnel Radio's family of rail products. Dependable two way communication between dispatch, trains, and maintenance crews will increase your tunnel's safety and productivity, and Tunnel Voice® gives you that dependable communication. When combined with our UHF radio systems, Tunnel Voice®, provides the complete tunnel communications solution: proven and reliable. Tunnel Voice® offers simplex dispatch as well as duplex narrow split operation, all within the AAR 160 MHz radio band.
Our 15 years of underground radio experience and our excellent field record guarantee system dependability. Across North America, our nation's largest railroads have installed the Tunnel Voice® radio technology in their tunnels. More than 500 miles of tunnels are currently operating across the United States and Canada, using our systems.

- Continuous voice communications--regardless of tunnel length
- Dependable communications between dispatch, trains, and maintenance crews
- All components are designed for the harsh tunnel environment
- Seamless full duplex radio coverage from surface to underground
- Amplified antenna network is extendable to any length tunnel
- No RF dead spots--regardless of tunnel length
- Low component count and easy maintainability
- Advanced VHF FD-4 amplifier technology
- 150 – 170 MHz
- Multiplies single and duplex narrow band channels

Tunnel Radio Link® is an extension system for Distributed Power and EOT/HOT systems. The system extends the radio signal for end-of-train and head-of-train communications no matter the tunnel length. It eliminates dead spots and increases radio signal ranges in the tunnel or a mountain pass environment. This patented technology is a major breakthrough in distributed antenna capability for UHF data systems.
Key Benefits
TMS - Tunnel Monitoring System

Tunnel Radio’s newest addition is the TMS Tunnel Monitoring System technology. When installed complementary to our TR-155 or TR-500 UHF UltraComm system, TMS enables and allows complete control and supervision of any mine utility by way of wireless. TMS is a diagnostic/monitoring technology that constantly tracks the condition of the UltraComm radio system and mine utilities. When the Tunnel Monitoring System detects a failure, such as a broken cable, or loss of power output, the condition is displayed on a VFD 4 x 20 line display. Fans, pumps, power centers, and even mobile equipment are controlled and monitored through Tunnel Radio’s TMS technology. It is also useable as a data link with MineAx tracking.
Tunnel Optic® enables the extension of VHF, UHF and other wireless services in difficult to cover tunnels and shadowed areas. This technology allows base stations, remote sites, and antennas to exchange high quality RF signals over a long distance; which makes it possible to obtain reliable communications inside a tunnel.
Each system consists of a head-end interface and Tunnel Optic®RF optical transmitter and receivers. The transmitter receives the RF signal, converts it into light, and transmits the optical signal over a fiber optic cable to the receiver, which reconverts the optical signal to an RF output signal with virtually no line loss.
Fiber Optic® RF equipment are protocol transparent, enabling them to carry all transmission standards, including CDMA, TDMA, AMPS, and GSM. Tunnel Optic® can also carry multiple services over the same fiber.
Each model comes with a variety of features. LED's, monitors, and alarms allow for complete system status monitoring and interfacing with M&C systems. One of the unique features is the serial data modem. An out-of-band sub-carrier is multiplexed with the RF signal over the same fiber, providing the most cost-effective method for monitoring and controlling RS232 communication. Another feature is gain control at the receiver site which optimizes both link gain and RF output level.