Tunnel Communication Radio System Project Overview:
In some locations, Reclamation uses underground tunnels, sometimes many miles long, to deliver water to our customers and to produce power. Inspecting and repairing these long, dark tunnels tunnels can be dangerous and intimidating---especially if you can't communicate well with support crews on the surface. Science and Technology Program Researchers at the Bureau of Reclamation developed and built a wireless tunnel communication system that dramatically increases the safety of tunnel inspection and maintenance crews, reduces costs, and minimizes tunnel outage times.
The researchers, reading a report that alluded to the frustration
of not being able to effectively communicate with crews in some
of Reclamation's long tunnels said "hey, we've got an idea."
Since there was no commercial equipment suitable for Reclamation's
tunnel work, they decided to develop and build their own specialized
tunnel communication radio system. They had great success testing
their equipment in tunnels in Colorado, California, and New Mexico
during maintenance operations. All of these tunnels are over 5 miles
long. As a result of these successes, they developed, tested, and
built radio systems that Reclamation field employees use today.
A patent application is underway, and Reclamation is investigating
ways to transfer the technology to the private sector.
The impetus for this project came from a safety issue raised in a 1993 Reclamation publication dealing with tunnel inspections:
Itineraries are left with surface crews to watch for the exit of the examination teams from the tunnels. This is because radio communications from inside a tunnel are not usually feasible.
The Hydroelectric Research and Technical Services Group, reading that field personnel were dealing with a difficult situation, responded by formulating a special research investigation in an effort to ease the burden. When the tunnel communication radio system project was undertaken, suitable commercial radios were not available for use in tunnels. Further, pressure to obtain communication means was brought about by OSHA regulations requiring voice communication in permit-required confined spaces. While wire communication systems exist, they have many disadvantages for non-permanent water-conveyance type tunnel applications. A wireless system would greatly enhance safety, reduce costs, and minimize tunnel outage times.
State-of-affairs research showed that radio wave propagation in underground environments improves as the frequency increases. Consequently, state-of-the-art hand-held 936-MHz radios were purchased for testing. Laboratory-grade test equipment was rented to determine the best frequency range for tunnel communication. Propagation tests took place in two Reclamation tunnels during the winter of 1997.
In 1999 a radio designed for the radio amateur market (GunnplexerTM Transceiver) was located that operates in the middle of the microwave frequency range previously determined to have the best chance of tunnel communication success. This equipment was purchased and tested in Hunter Tunnel, near Basalt, Colorado. The results were so impressive that other successful tests were performed in Clear Creek Tunnel near Redding, California, during cleaning operations, and in Blanco Tunnel, Chama, New Mexico, during maintenance operations. All of these tunnels are over 5 miles in length.
As a result of these successes, and due to the fact that there still was no commercial equipment suitable for Reclamation’s tunnel work, it was decided to develop our own specialized tunnel communication radio system. With FY 2001 funding from the Chama Field Division, the Eastern Colorado Area Office, and the MP Regional Office, the new radio system was developed, tested, and four communication sets (consisting of two radios each) were built. Science and Technology funds were highly leveraged for this research, development, and demonstration project. Deployment funding came from field service request agreements for complete systems. One radio set remains with 86-68450. The other sets were delivered to the above-named offices. These radios have all performed in the field as intended, providing continuous voice communications between maintenance crews inside and outside the tunnels at distances up to 13 miles (longest tunnel available).
The latest success in March 2002 was at Pacheco Tunnel which is operated by the Santa Clara Water District in northern California. The MP Region provided their radio set for a tunnel inspection. The following unsolicited feedback came from a Reclamation employee at the site:
In case you have not already heard, the equipment you [TSC] put together worked great. We had no problems communicating the 5+ miles in the Pacheco tunnel. . . . The water district folks were very pleased and talking about getting one for themselves. You guys did a great job putting the Tunnel Communications set together and it was a pleasure using it. Thanks.
To complete this research-initiated program, a patent application is underway for technology transfer purposes to enhance marketing and commercialization potential (i.e., deployment).
A request for an invention by a user rarely occurs. It takes someone removed from the situation and watching the user dealing with a limitation to say "hey, I’ve got an idea." Usually the innovator wanders off to develop a solution. In this case, the user was not even aware that 2000 miles away someone read the disguised plea for help and went off to do something about it. The need for an innovation isn’t easily identified, and a request to provide a specific innovation is seldom received. Such is the innovative/creative process. Can this process be planned? Managed? No, not exactly, but only sort of. Planning and managing research is often times likened to herding butterflies. You can sort of guide them to the correct garden, but what flower they light on is anyone’s guess. We did land in Reclamation’s yard, and we are very happy we were able to make a small contribution. (Phil Atwater, 303-445-2304 / Bert Milano, 303-445-2300)