Caltrain officials received "a lot" of comments from the public, both via telephone and e-mail, asking Caltrain to reduce the volume of trains after the agency was forced to raise the decibel levels to meet the Federal Railroad Administration regulations, Caltrain spokeswoman Christine Dunn said.
Federal regulations specify the decibel level, the sequence of blasts and when the horn must be used. To meet federal requirements, the decibel level must be between 96 and 110 decibels, and the engineer must sound two long, one short and one long blast on the horn a quarter of a mile before entering a grade crossing, according to Dunn.
When it was discovered about a month ago that Caltrain's horns could not produce the sequential blasts required by law, the agency quickly came into accordance with that regulation and moved the horns from the bottom of the trains to the top so they would be louder, Dunn said.
Having the horns on the top of the trains disperses the sound over a wider area, and enables engineers to perform the required sequential blast, according to Dunn.
But the noisier Caltrain horns were not well received among members of the community who live near Caltrain stations, according to Dunn.
"As soon as we moved the horns up to the top of the trains, we started hearing from people that they were much louder," Dunn said.
The agency is investigating whether the horns can be moved back below the trains and still meet federal regulations, an investigation that could take several weeks, she said.
In the meantime, Caltrain has installed a regulator valve that allows the volume to be precisely set on locomotives and cab cars, and have turned the volume to as low as possible while still meeting federal regulations, according to Dunn.
"The horn's still at the top, but the volume has been reduced," she said. "We have reduced it as low as we can to still say within those regulations."
"We understand that it has really been a nuisance for people and we regret causing as much inconvenience as we have," Dunn said. "We're working very hard to try to correct it."