The board of the San Francisco Municipal Transportation Agency (SFMTA) agreed to spend $212 million to take its Muni Metro light rail off the floppy disks.
The Muni Metro Automatic Train Control System (ATCS) has required 5¼ inch floppy disks since 1998, when it was installed in the Market Street subway station in San Francisco. The system uses three floppy disks to load the DOS software that controls the system’s central servers. SFMTA spokesperson Michael Roccaforte gave more details about how light rail operates to Ars Technica in April, saying: “When a train enters the subway, its onboard computer connects to the train’s control system to run the train. in automatic mode, where trains drive themselves while operators supervise. “When they exit the subway, they disconnect from ATCS and revert to manual operation on the street.”
After beginning initial planning in 2018, the SFMTA originally hoped to move to a floppy-diskless train control system by 2028. But as Covid-19 prevented work for 18 months, the estimated completion date was pushed back.
On October 15, the SFMTA came closer to ditching floppy disks when its board approved a contract with Hitachi Rail to implement a new train control system that does not use floppy disks. the san francisco chronicle reported. Hitachi Rail technology is said to power train systems, including Japan’s bullet train, in more than 50 countries. The $212 million contract includes support services from Hitachi for “20 to 25 years,” the Chronicle said.
The new control system is supposed to be five generations ahead of what Muni is using now, Muni Director Julie Kirschbaum said, according to the Chronicle. To further illustrate the aging technology of light rail, the current ATCS was designed to last 20 to 25 years, meaning its expected expiration date was in 2023. The system still works well, but there is a risk of degradation of the data on the floppy disk and challenges in maintaining expertise in 1990s programming languages have further encouraged the SFMTA to seek updates.
Lots of work to do
Beyond the floppy disks, however, the Muni Metro needs many more improvements. The SFMTA plans to spend $700 million (including the $212 million Hitachi contract) to overhaul the light rail control system. This includes replacing the looped cable system to send data through servers and trains. Cables are said to be a more pressing concern than the use of floppy disks. The old cables are fragile, with “less bandwidth than an old AOL dial-up modem,” Roccaforte previously told Ars. The SFMTA is reportedly planning to have Hitachi begin replacing loop cables with a new communication system that uses Wi-Fi and cellular signals to track trains by 2028. However, the SFMTA board of supervisors still needs to approve this, said the Chronicle.
In addition to the old storage formats and communication infrastructure, Muni’s current ATCS includes onboard computers connected to the propulsion and braking systems, as well as local and central servers, and more. The SFMTA website says the current estimated completion date for the full review is “2033/2034.” Based on the timeline provided, it appears that the subway technology replacement phase is expected to take place in “2027/2028,” after which there is a technology installation phase on the track.
As with other entities, SFMTA’s slow exit from floppy disks can be attributed to complacency, budget constraints, and complications in overhauling critical technology systems. Several other organizations have also been slow to ditch the dated storage format, including in Japan, which only stopped using floppy disks into government systems in June, and the German navy, which is still trying to figure out a replacement for 8-inch floppy disks.
This story originally appeared on Ars Technique.