A Muni conductor erred and failed to stop the cable car he was guiding to a stop-point at the downtown end of the California line in time to avoid a collision with another cable car on Friday morning, an investigation by the San Francisco Municipal Transportation Agency found.
Two operators were sent to hospital and released later in the day following the 8:16 a.m. collision at the corner of California and Drumm streets, according to SFMTA spokeswoman Kristen Holland.
The accident disrupted service on the California line for almost five hours, according to Holland.
Cable cars are operated by two people — a conductor who collects fares and is responsible for safety and a gripman who drives the tram, according to Holland.
The crash was blamed by Muni investigators on “human error” on the part of the conductor, who was guiding the cable car to the stop-point in neutral to give the gripman a break from driving, according to Holland.
It has been common practice for the conductors to occasionally move the tram to the stop-point to give the gripman a brief break, but that practice will now be banned, according to Holland.
No passengers were on board either cable car at the time of the crash, which occurred on flat ground at speeds below nine miles per hour, according to Holland.