When Congress soon convenes hearings on what went wrong at the Crandall Canyon Mine where six coal miners were killed earlier this month, rather than just grilling company officials, lawmakers should look at what progress has been made in meeting the requirements of a sweeping law passed last year after mine disasters killed 18. In the area of communications, for example, they are likely to find that progress is painfully slow.

Prompted largely by the disaster at the Sago Mine in West Virginia that killed 11 miners, Congress last year passed the Mine Improvement and New Emergency Response, or MINER, Act. It required that all coal mines adopt accident preparation plans, with an emphasis on communications.

After the Aug. 6 cave-in at the Crandall Canyon Mine in Utah, mine officials were unable to confirm where the trapped miners were. Many outside the industry wondered why the miners did not have GPS units or other means to relay their location.

A major technical problem is that relaying communications signals through the earth is difficult. At more than 1,500 feet below ground, the Utah miners would have been especially hard to track.

Mines now typically have phone lines strung along the tunnel ceiling and some miners are equipped with radio frequency ID tags that can relay their location through fiber optic cables strung in the mine. Cave-ins typically disrupt these types of communications.

Interference from all the equipment in a typical mine and the fact that mine gas could easily be ignited by a communication system’s power source make mine communication extremely difficult.

Still, Congress appropriated $10 million for work on communication, refuge areas and oxygen supplies in mine disaster. The National Institute for Occupational Safety and Health has been coordinating work in these three areas for nearly a year. NIOSH scientists have worked with inventors and manufacturers and tested several prototype communication system. However, its assessment of the possibility of better systems soon emerging is pessimistic. Although it had identified a number of “opportunities” with a reasonable likelihood of being available for in-mine use within three years, it warned that this wasn’t likely for $10 million. To maximize the money, the institute planned a competitive process to identify – and presumably fund – the technology most likely to be commercially available within three years.

In the meantime, more miners will be trapped without being able to communicate with the outside world. If this is a priority, Congress should shorten the timetable and provide more money.