Sonoma-Marin Area Rail Transit grinds through tech challenges
Sonoma Marin-Area Rail Transit may be able to open its doors with commuter-train service between Santa Rosa and San Rafael in the fourth quarter of 2016, but it's going to be a race. Engineers on the $500 million project are working to solve a slate of engineering puzzles that come with coordinating the new rail, vehicles and signals.
'With a brand new rail vehicle, we have a brand-new state-of-the-art signaling system,' said Bill Gamlen, SMART's chief engineer. 'And we have brand-new grade crossings. We have been focused on each of these components. Now we're bringing them all together and testing. Various things come up as part of that. ... You have electronics, new vehicles, new wheels. Everything has to wear together and be integrated.'
In August, test trains reached speeds of less than 30 miles an hour. Top speed of the trains will eventually hit 79 miles an hour, Gamlen said, but only in open sections such as north of Santa Rosa or between Petaluma and Novato. Bullet trains in Japan reach 200 miles an hour. The world record for a maglev train was set in April 2015 at 374 miles an hour on an experimental track in Yamanashi.
'We're not high-speed rail. We're commuter rail,' said Gamlen, who oversees a team of six engineers. SMART's big advantage for commuters is avoidance of the Novato narrows section of Highway 101, which jams up every weekday morning and afternoon. When the train opens, SMART commuter fares will typically run $13 a day round-trip, with electronic ticketing through Clipper cards.
'We are bringing all this stuff online,' Gamlen said. 'We have been moving at relatively slow speeds on the railroads, not quite up to our design speeds. Grade crossings are timed for a certain speed — a passenger speed of 50 miles per hour. At 30 we're coming in the system is expecting to pick you up at 50 and operate at that speed. There are those kinds of issues as well.'
'It's a step process, Gamlen said. 'First we focus on the grade crossings. Then we start integrating the vehicles. Then we start integrating the signaling system. Then we start ramping up the speeds.'
The section of track between Santa Rosa and San Rafael is known as 'dark territory,' Gamlen said, where previously there was no signaling system. 'We have pulled fiber throughout the corridor to support that, to support our communication need,' he said. 'The biggest challenge is bringing all this together.'
Santa Rosa-based Sonic installed the fiber-optic cable along the train track in exchange for access to the right-of-way. 'We put in the conduits and they pulled all the fiber,' Gamlen said. 'It was a good deal for both parties.'
'Sonic is providing fiber-optic communications for their signals and controls,' said Dane Jasper, Sonic's founder and CEO. 'Alongside it, we can send our own traffic as well. We get to use their right-of-way,' serving business parks near the track with broadband access.
Other technical challenges remain for SMART. New continuous welded steel track came in 1,600-foot sections made by Allegheny Rail Products, located in Pueblo, Colo.
The fresh track was covered in mill scale, a flaky surface found on hot-rolled steel composed mostly of magnetite, a blue-gray iron oxide made of three atoms of iron married to four atoms of oxygen. Scale also includes other iron oxides — an inner layer of black wüstite, FeO, and a thin outer layer of hematite, Fe2O3. In recent months, SMART engineers used a grinder to shave off mill scale.
The scale had to be removed because train wheels require clean electrical contact with rails in order to communicate with signals that stop traffic from traversing the track while the train goes by.
'It's part of the process,' Gamlen said of mill-scale removal, which is ongoing.
There are two types of rail grinding.
Surface grinding takes off scale and imperfections created in milling the steel. It's to 'accelerate that process of getting a nice wheel-wear patch on the rail,' he said.
Then there's profile rail grinding. 'You grind a wheel profile to match the rail head, and the rail head to match,' Gamlen said. The rail head is the top part of the rail profile (cross-section) where wheels of the train roll.
'It's a little more common in light rail,' Gamlen said, and helps to reduce noise and vibration. 'Sometimes freight railroads pursue it as well for longevity,' where trains bear heavy tonnage. 'Whatever they can do to not have to replace track — it's all about making money for them,' he said.
For SMART, profile grinding translates to ride quality, Gamlen said. 'We spec'd a particular wheel and the rail to match,' he said. 'At this point we're not trying to get into the science of matching a particular wheel profile. That could come down the road if you had some issues or you want to improve ride quality.'