Repost from the Contra Costa Times

Derailment: Should rail tracks have fence sensors in landslide prone Niles Canyon?

By Matthias Gafni, Sam Richards and Thomas Peele, 03/08/2016 07:09:45 PM PST

SUNOL — A deep stretch of Niles Canyon where a crowded commuter train from San Jose derailed Monday night is fraught with landslides, yet it lacks a system to alert engineers that their path may be blocked by mud or toppled trees.

But officials — who called it an “absolute miracle” no one was killed — said that may change.

Altamont Commuter Express Spokesman Brian Schmidt said the transit agency, which resumes service Wednesday, will talk with track owner Union Pacific about installing fencing in the area with sensors that set off alerts when hit by trees, mudslides or falling rocks. That is similar to what has been done along the Feather River Canyon in northeastern California and in western Colorado. The sensors have been available but are not widely used, and there are none in the slide-prone Niles Canyon.

“If there’s any place in the Bay Area to have a landslide, Niles Canyon is it,” said Jonathan Stock, a USGS geologist who has studied the area. “It has a long history of things going bump in the night.”

The first two cars of ACE train No. 10, with 196 passengers aboard, derailed between Sunol and Fremont around 7:15 p.m. Monday, with the lead car tumbling into rain-swollen Alameda Creek. As water filled the partially submerged car, passengers frantically worked to free injured riders.

Nine people were injured. Four of the injuries were serious, though not life-threatening, and one patient — a 24-year-old man — remained hospitalized Tuesday in good condition.

Using two cranes, crews started pulling the submerged lead car out of the creek on Tuesday afternoon, while the other four cars were moved down the track.

Federal Railroad Administration investigators, as well as those from the California Public Utilities Commission and track owner Union Pacific, are involved in the investigation. It was unclear Tuesday whether the landslide broadsided the train as it rolled past at 35 mph, in the 40 mph zone, or if the slide happened beforehand and the train crashed directly into the debris. Other trains went through the canyon earlier Monday and apparently did not report problems.

Christopher Chow, a PUC spokesman, said the agency sent two inspectors to the scene Monday night, and they remained on-site late Tuesday.

“Their focus is on identifying the root cause of the incident and collecting evidence to determine if there were any violations by ACE,” Chow said. “As part of the investigation, we will be reviewing relevant records, including our last inspection of the track.”

FRA accident data identifies 325 train derailments in California between 2011 and 2015. All but eight involved freight trains. Three people were injured, data show. There were no fatalities.

Alameda County Supervisor Scott Haggerty, a member of the ACE board, agreed it’s time to talk about installing slide fences with sensors.

“One thing we can’t ignore is technology, and we have to continue to look at what’s available, and use what’s appropriate,” Haggerty said Tuesday.

Stock reviewed photos of the hillside above the crash site and said it appeared that the unnaturally steep slope created when the line was built, aided by heavy rain, caused the debris flow and tree fall that investigators say likely caused the train to derail.

“That’s an old cut from when it was blasted for the railroad to go through,” said Stock. “It appears to be a small, thin failure off a modified piece of landscape.”

With tracks historically built on the flattest possible ground, often near rivers in valleys and canyons alongside steep hills, “washouts” in the industry are fairly common, said Gus Ubaldi, an Ohio-based engineer who specializes in railroads.

Even with frequent inspections, washouts are nearly impossible to predict, and “can happen in an instant. It’s an act of God,” he said.

Union Pacific inspects its track through Niles Canyon at least twice weekly, Schmidt said, with additional inspections done when storms, earthquakes or other weather- or geology-related events occur, as required by federal regulations. Locomotive engineers operating freight and passenger trains through the canyon also keep an eye out for any slide potential, Schmidt added. In addition, state and federal regulations require regular vegetation maintenance.

The decision to halt service can be made if a storm is deemed a threat to train crew or passenger safety. All UP tracks in California are subject to a “very robust” inspection process, and the tracks had gone through an additional “stormwatch” inspection just ahead of this weekend’s rainstorms, said Francisco Castillo, a Union Pacific spokesman.

Because there were no other slides reported from the recent storms — the area received about 2.13 inches of rain since March 1, according to the National Weather Service — Stock speculated that the ground movement started from a saturated tree falling, pulling debris down onto the tracks with it. An Alameda County sheriff’s deputy said the smell of eucalyptus, a tree prone to fall during landslides, was overwhelming at the scene Monday night. He also saw the tracks littered with shards of tree branches.

Whatever brought the hillside down was not unusual for the area.

Stock said he’s found at least five newspaper articles on major slides since the 1860s impacting rail traffic. In December, the Alameda County Public Works department issued a study concluding “the entire Niles Canyon corridor is notorious for rockslides and landslides, which often activate during rainfall or seismic events.” A 2004 California Geological Survey study reached the same conclusion.

The Pacific Locomotive Association, which runs the six-mile historical Niles Canyon Railway on the north side of the canyon, fights mudslides and related issues every few years. The most recent was on Christmas Eve 2013, said President Henry Baum; the mudslide didn’t cover the rails but diverted water runoff that undermined the track and closed it temporarily.

“We spend a lot of time and money cleaning up small slides making sure they don’t turn into big ones,” he said.

The only landslide in Niles Canyon that Schmidt said he could remember since ACE started operations in October 1998 was a small one several years ago encountered by a Union Pacific freight train. That train did not derail, he said.

Many years before ACE started operations, a landslide damaged a part of the current-day ACE line alongside Old Altamont Pass Road about a mile west of the old Altamont summit. That resulted in a “shoofly” built around the slide area, a little curve in the track that became permanent.