An apparently unprecedented, super freight train extending about 3 1/2 miles rolled through Southern California over the weekend, catching state regulators off guard and prompting concerns about potential safety risks and traffic delays, The Times has learned.
Union Pacific said that the train was used to test equipment and find ways to improve operating efficiency, but that the company had no plans to run such trains regularly.
Some officials worry that the train may be a harbinger of things to come in a crowded region where passenger and freight trains already share tracks that cross hundreds of intersections bustling with cars and trucks.
"I will be asking a lot more questions," said Democratic U.S. Rep. Grace Napolitano, whose San Gabriel Valley district includes part of the train route.
"If they're testing to increase the size of trains in L.A., I have a problem with that," she said.
The state Public Utilities Commission raced a team to Imperial County on Saturday to monitor the train as it headed toward the Inland Empire. The train originally left Texas on Friday night and reached its ultimate destination, a large intermodal facility near the Port of Long Beach, on Sunday.
"We were quite concerned about it, which was why we scrambled our people to be out there Saturday to essentially find out what was going on," said Richard W. Clark, who oversees rail safety at the PUC.
There are no state or federal limits on the length of trains or requirements to notify agencies about unusually long trains, officials said. Union Pacific said it did alert local federal regulators, who observed the train's movement.
The 18,000-foot-long train was two to three times the length of a typical freight train, Clark said, and the largest he knew to operate in the state.
It linked 295 rail cars, carrying more than 600 cargo containers, mostly double-stacked, said Tom Lange, a Union Pacific spokesman. Nine locomotives were spread along the train and additional personnel were on board to monitor equipment.
The train, the longest ever assembled by Union Pacific, was permitted to travel up to 65 mph as it crossed the Los Angeles Basin, Lange said. He said the train needed three to five minutes to clear a grade crossing.
The test was part of an effort to explore ways to "better serve our customers," Lange said. Such trains reduce the chances of derailment, he said, because locomotive power is distributed along the train, easing stress on couplers and other equipment.
In addition, although a long train might extend waits at an individual intersection, it would reduce overall waiting time compared to three shorter trains, Lange said. That's because crossing signals begin stopping traffic 20 to 25 seconds before each train arrives. The long train tested over the weekend was the equivalent of three mile-long trains, which would have added 40 to 50 seconds to total motorist wait time.
Still, Napolitano, who sits on the House Transportation and Infrastructure Committee, said that because there are 54 grade crossings in her district, she is concerned about traffic tie-ups.
"I don't believe three to five minutes," she said, referring to the estimated motorist waits. She said she also would look into safety risks in the event of a derailment by such a large train.
No incidents were reported during the weekend test, but state regulators were continuing to examine issues raised by such operations, Clark said.
His agency will look into what is required to safely brake a train 3 1/2 miles long, as well as possible delays for emergency responders if intersections are blocked for longer times.
Of particular concern would be scenarios in which "the hospital is on one side and the crash or heart attack is on the other side and the ambulance can't get across," he said.
The state now prohibits stopped trains from blocking an intersection for more than 10 minutes.
Union Pacific's Lange said such issues are not new because mile-long trains also can block intersections. The railroad works with local emergency agencies to plan alternate rescue routes, he said.
At least for now, logistical issues probably will limit the use of such trains, according to the Federal Railroad Administration.
"There are operational problems, like siding lengths," said spokesman Robert Kulat, who added that most sidetracks off railroad main lines can't hold such trains. It also can be "difficult to maintain radio communication" on such long trains, he said.
As for braking distance, it can take about one mile to stop a mile-long freight train, Kulat said. That should be about the same for a much longer train, assuming that proper communication and control is maintained with trailing locomotives, he said.
In general, federal regulators have not raised concerns about longer trains, he said. "It's recognized that it's an efficient way to move goods," he said.