Norfolk Southern needs locomotives to reliably deliver freight, but the railroad owns a special fleet that will never pull a single ton – or cost a dime to fuel and maintain. To the NS technology engineers who “operate” them, though, these locomotives produce incredibly high value at bargain-basement costs.
Meet NS’ virtual locomotives. The only place you’ll ever see them run is on the “rails” of the company’s state-of-the-art Positive Train Control Virtual Lab.
As the rail industry moves to implement a fully interoperable PTC system, NS has developed a high-tech way to test still-evolving PTC technologies.
“PTC is a complex system,” said Warren Stubbs, NS director information system development. “Ensuring that all components are working as expected is daunting. The challenge is magnified by a steady stream of upgrades and fixes – it’s impossible to upgrade every component of every locomotive across our system simultaneously.”
Enter the virtual locomotive. Software imitates a diesel locomotive’s on-board computer and performs like a diesel locomotive. Compared to the real thing, a virtual locomotive is cheap. It’s also flexible – the system can simulate multiple locomotives at the same time and can be reconfigured quickly and easily. Traditional testing would tie up actual locomotives at much greater cost and with far less flexibility.
The PTC lab, located in the company’s operations center in Midtown Atlanta, provides NS engineers a safe, convenient, and efficient way to test the extremely complex hardware and software that composes the “brain” of PTC on a locomotive. That complexity is borne out of the dozens of versions and upgrades of onboard systems – more than 700 different permutations so far, and growing.
With the virtual test system, Information Technology can run hundreds of test scenarios against each hardware and software configuration. Testing is quick, thorough, and cost-efficient. Bugs are found early and easily, allowing the PTC Virtual Lab team to focus on further improvements and additional testing.
“In the lab, automated testing plays a huge role in preparing systems for the field,” said Stubbs. “Of course, we continue to perform additional tests on real locomotives once lab testing is complete, but virtual test locomotives have been a very important part of NS’ success in achieving the goals of our PTC implementation plan.”
Using virtual locomotives to do all that testing costs next to nothing compared to using the real thing, Stubbs said. So far, NS has invested about $100,000 to build 720 PTC virtual locomotives.
“We needed hundreds of locomotive configurations to properly test our PTC systems, so we bought the hardware and software we needed and built them ourselves – and spent less than we would to buy a 30-year-old diesel locomotive,” Stubbs said. “Managing assets and controlling costs are key components of NS’ strategic plan, and we think this is a good example of how we’re helping to achieve those goals.”
Leveraging virtual reality to test PTC software is one more way that NS is using technology to reimagine possible.