Engineers on California's high-speed rail project have worried for nine years about the sort of train wreck that occurred in New York last October.
Six hundred rail passengers were rolling across Long Island at 50 mph on a Saturday night when a maintenance train on a parallel track derailed and sideswiped their commuter train, injuring 33 and leaving others wandering in the dark through twisted wreckage.
Although construction on California's high-speed rail is already underway, designers are still sorting out safety's place in a delicate balance that also requires staying on budget and getting passengers from Los Angeles to San Francisco on time. One safety concern playing out at the moment stems from the fact that the bullet trains will run in some places at 220 mph, alongside lines carrying everything from toxic chemicals to military tanks.
Everyone agrees barriers are needed to keep debris from derailed freight trains from smashing into the fast-moving passenger cars. But for years freight train operators and the California High-Speed Rail Authority could not agree on their exact design.
They finally reached agreement last year. And only then did the contractor for the 31 miles of track in and around Fresno put a price tag on the work: an additional $140 million.
At least some experts see that bump in the bill as a worrisome harbinger.
Cost increases, after all, have dogged the bullet train for years, and new jumps in price may start surfacing as the complex engineering needed for passenger safety comes into clearer focus.
Aside from the debris barriers, the range of safety issues includes how bullet trains will operate in dense urban environments where they cross highways, how to contend with the possibility of fires and other mishaps in the long tunnels they'll pass through, and the type of brakes necessary to slow them on steep downhill grades.
In creating any public transportation system, designers must balance such considerations against cost and performance. But California's high-speed rail planners have little freedom to negotiate such trade-offs, because state law dictates that its bullet trains need to get passengers from downtown Los Angeles to downtown San Francisco in no more than 2 hours and 40 minutes.
"I would never expect the rail authority to sacrifice safety to save money," said Louis Thompson, the chairman of a state-appointed peer review panel for the project and a former executive at the Federal Railroad Administration. So it's "entirely possible," he said, that new safety problems or ones that emerge as more serious than first thought will drive up the cost.
"Safety is a top priority of the California High-Speed Rail Authority," said rail authority spokeswoman Lisa Marie Alley. "We continue to work with our partners to ensure that we are designing and building a system that is safe and secure."
And almost certainly, the rail agency will confront new and difficult trade-offs between cost, performance and safety.
The authority decided, for example, to share track from San Jose to San Francisco with the Caltrain commuter service, instead of building its own track on an elevated viaduct through Silicon Valley. That saved the project about $30 billion.
That means crossing 42 highways, a safety risk that planners would address by installing elaborate gates to fully block the intersections, where about 13 fatal collisions between standard-speed trains and motor vehicles already occur every year.
It also means slowing the trains to a proposed 110 mph, half the speed the train will be hurtling along at through parts of the Central Valley. That speed is still far faster than most U.S. passenger trains operate in such dense urban settings, experts said.
But at least some question whether even 110 mph is realistic.
"In a dense urban environment you are not going to go 110 mph," said Grady Cothen, an attorney and former chief of safety regulation at the Federal Railroad Administration. "If you eliminate the possibility of dedicated track, then you are certainly knocking down the maximum speed and increasing the trip time."
The alternative is to separate the highway crossings with bridges or tunnels, an effort that could cost additional billions of dollars.
If the trains go slower than 110 mph, the project could well fall short of the overall trip times that legislators built into the project's requirements and supporters used to sell it to the public. The same dilemma will confront the rail authority as it fine-tunes how trains will move from Burbank to Anaheim, where they will likely share track with Metrolink.
Alley, the rail authority spokeswoman, said the routes will have features "to achieve the highest safety and comply with federal standards."
But Steven Ditmeyer, a rail safety consultant and former research chief at the Federal Railroad Administration, accused legislators of hobbling the professionals who are best equipped to find the right balance among cost, safety and performance.
"There are many many trade-offs that have to be made," he said. "And somebody in the Legislature didn't want the engineers making those trade-offs."
Long tunnels will also require additional safety planning. Between Bakersfield and Los Angeles, trains will travel about 40 miles under parts of the Tehachapi and San Gabriel mountains.
The project cut its budget by $1.6 billion by planning to eliminate mechanical ventilation, relying instead on a strategy to "compartment" smoke in a train fire, and by reducing the diameter of tunnels, according to documents in the rail authority's 2016 business plan.
That approach is part of a plan is being shared with the Office of the State Fire Marshal and other regulators to ensure it meets safety requirements, Alley said.
Another trade-off will involve trains' downhill speeds in mountainous areas. The most challenging stretch is the 4,025-foot drop from the Tehachapi Pass to Bakersfield.
If the trains run at full speed, they may need a new type of brake technology, according to a 2013 rail authority memorandum. One possibility is a type of brake that magnetically transfers heat into the rails. It has been used in some rail systems, but not under the challenging technical conditions of the California mountains, according to rail industry executives.
Alley said the authority is also considering other less precipitous routes.
Recent discussions about the Central Valley barriers show that trade-offs already are driving up costs.
As far back as 2008, the rail authority had begun technical investigations into how it would prevent debris from a freight derailment from fouling its tracks, with engineers proposing that physical barriers be constructed anywhere freight and high-speed tracks were within 102 feet of each other.
The threat of debris from derailments hitting passenger trains is not theoretical.
The Times located records on the Federal Railroad Administration's safety database showing that on average there are 10 freight train derailments a year in the Central Valley's five southern counties. Across the nation, more than 1,000 trains derail every year, the database shows.
In last year's accident on Long Island, a federal report said the maintenance train derailed when it crossed a switch locked in reverse, a human error.
Worn wheels, defective axles, weak crossties and misaligned rails, as well as human error, also cause derailments. Nature can play havoc, as well.
An Altamont Corridor Express train derailed a year ago when a mudslide pushed a downed tree onto the tracks about 45 miles east of San Francisco. The derailed train plunged into a creek, injuring nine people.
At bullet train speeds, such accidents are more deadly. A 2013 crash of a Spanish Alvia train killed 79. A 2015 derailment in France killed 11. A 1998 derailment in Germany killed 101. And a 2011 collision of two bullet trains in China left 40 dead.
Many high-speed rail lines in other parts of the world separate passenger trains from freight trains. But the bond act that launched California's high-speed rail project requires it to share existing transportation corridors, so freight train debris is another serious derailment threat.
Discussions about the exact design of the barriers on California's high-speed rail project dragged on for years.
Freight carrier Union Pacific finally agreed that keeping the tracks 102 feet apart should be the standard about a year ago, according to an attorney close to the railroad. The other major freight line, BNSF, reached its agreement only in December, said spokeswoman Lena Kent.
Because Union Pacific demanded stronger structures, the costs have grown to about $10 million per mile, said an official knowledgeable about the negotiations.
But when Sylmar-based contractor Tutor Perini Corp. sent the rail authority a letter adding a proposed $140 million to its bill for building the barriers along 31 miles of track in the Central Valley, the officials balked.
The money "simply does not exist for these change requests," chief engineer Scott Jarvis wrote in an internal email that The Times obtained under a public records act request. So, Jarvis said in the email, the authority would begin searching for cheaper alternatives.
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