Database technology moves Bay area
The San Francisco Bay Area Rapid Transit (BART) District is composed of 150 miles of track that carry trains transporting approximately 300,000 passengers every day. Keeping the trains running smoothly and maintaining the highest levels of passenger safety is a big job. But BART manages to do just that with only one employee aboard each train.
That’s because BART is fully automated and has been since shortly after World War II. Still, the computer system that had been running the show for 50 years did not allow for the geographic expansion necessary to extend the line to San Francisco International Airport, which will be completed in the year 2000. Nor did it allow for any increase in passenger capacity. Additionally, its 20-year-old computers were no longer being built or serviced by the manufacturers.
These limitations proved critical in San Francisco, which is located in one of the fastest growing areas of the country. City officials, consequently, decided an upgrade was in order.
“Seven years ago we decided to upgrade BART’s computing environment and move to a distributed, open and scalable environment,” BART System Engineering Group Manager David Warwick says. “We also wanted a system that was independent of hardware manufacturers.
“We knew these were important factors in saving both time and money,” he says. “The upgrade allowed for the system to grow and improve, as well as ensuring the safety and efficiency of our passengers.”
Now, BART uses its database management system as the foundation upon which all the application software operates. The system has an automatic fare collection mechanism, which includes the convenience of debit/credit ticket purchasing to help passengers buy and redeem their tickets every day. It also handles BART’s network management (BARTnet data communication system) and telecommunications needs, including dispatch and radio communications.
Passenger safety was one of the primary motivations behind the $200 million upgrades. To ensure maximum safety for all its passengers, BART has a main control room that monitors the action across the entire system. Transbay Tube, the 6-mile main tunnel that runs under San Francisco Bay, is monitored by the system, and the data is displayed graphically on color monitors that are watched 24 hours a day.
Designing and implementing the control center was expected to take approximately four years. However, BART developed the software in-house and was able to install both the display and electric boards in half the allotted time.
The police and maintenance dispatchers, located in the main control center, monitor board displays of information from 30,000 data points that are polled every 23 milliseconds. The data points check the locations of all 54 trains and monitor: * whether doors are open or closed; * whether emergency telephones are working; * whether tracks are occupied; * whether direction control switches are locked and aligned; and * whether exhaust and tunnel ventilation fans and circuit breakers are operating properly.
If a problem such as a fire in the tunnel or an inoperable phone arises, the command staff can respond within seconds, correcting the situation with a single key stroke.
Future plans for the system include upgrading the network to a SONET fiber-optic backbone, which will create a higher capacity in performance between stations. “We are always upgrading and maintaining the system,” Warwick says. “And we are always looking for ways to make it easier and more convenient.”
