Oakland Wye

Oakland Wye
 
Richmond–Warm Springs/South Fremont
Antioch–SFO/Millbrae
Richmond–Daly City/Millbrae
Warm Springs/South Fremont–Daly City
Dublin/Pleasanton–Daly City
Warm Springs/South Fremont–Daly City
Dublin/Pleasanton–Daly City
Antioch–SFO/Millbrae
Richmond–Daly City/Millbrae
Richmond–Warm Springs/South Fremont
 

The Oakland Wye is an underground rapid transit flying wye junction in downtown Oakland, California which serves the Bay Area Rapid Transit (BART) system. Trains can switch between (a) the northbound Richmond or Pittsburg/Bay Point lines (first station: 12th Street/Oakland City Center, underground), (b) the westbound San Francisco lines (first station: West Oakland, elevated), and (c) the southbound Fremont or Dublin/Pleasanton lines (first station: Lake Merritt, underground).[1][2][3][4]:45–46 The Oakland Wye has been described as one of the central and most complex parts of the BART system, and is a speed bottleneck for the whole system because all BART trains pass through it.[1][5]

Design

Line diagram schematic of the Oakland Wye, a flying interchange that allows trains to bypass West Oakland (track C2→A1 or C1←A2), or pass through the Transbay Tube (M2→A1, M2→CX, or M1←C2)

The original operating speed through most of the Oakland Wye was intended to be 27 mi/h (43 km/h). Design problems led BART operations to impose a 18 mi/h (29 km/h) administrative speed limit on most tracks. Although the design has since been corrected, the speed restrictions remain as a cautionary measure.[1] The track turning north from West Oakland station through 12th Street/Oakland City Center is the only track with a higher operating speed of 36 mi/h (58 km/h) through the Wye.[1]

Bypasses that would connect MacArthur and Coliseum with the Transbay Tube directly have been proposed to create express service, avoid systemwide delays if glitches occur in the Wye, and potentially provide an infill station at Jack London Square.[6] Other infill stations or more frequent service may be provided in urban core areas if a turnback is built in the Oakland Wye.[7]

History

Incidents

In February 2000, automatic train controls failed due to an electrical short, and trains proceeding through the Oakland Wye were forced to operate in manual and slow to 5–10 mi/h (8.0–16.1 km/h) when switching tracks. Crews were dispatched to manually switch trains between tracks in the Wye, resulting in long delays during the morning commute.[8]

In February 2009, two northbound trains from West Oakland and Lake Merritt sideswiped in the Wye while heading north towards 12th Street/Oakland City Center. Both trains partially derailed. The automatic train control system should have prevented the collision, but one train was operating in manual mode.[9] After the trains were cleared from the tracks early the next day, BART released a statement noting the train operating in manual had proceeded past a wait point,[10] and the NTSB provided an investigator to assist.[11]

In January 2017, a westbound ten-car train arriving at West Oakland stopped partially outside the station, with only the first seven cars on the platform. The resulting backup delayed all train traffic entering the Transbay Tube from the East Bay, and forced commuters to take alternative means to their jobs, including ferries, buses, and ridesharing services.[12]

References

  1. 1 2 3 4 "BART Sustainable Communities Operations Analysis" (PDF). Bay Area Rapid Transit. June 1, 2013. Retrieved July 31, 2017. Station to station running times can identify areas within the system that may be susceptible to delay resulting from either speed / operating restrictions or from infrastructure issues. One of the key locations within the BART system is the Oakland Wye. The Oakland Wye is a multi-level interchange between West Oakland, 12th Street and Lake Merritt stations. BART provided information on the running times between these stations to identify any possible issues with regards route selection, route clearing and secondary delays. The information indicates that actual performance through the Wye is largely consistent with scheduled speeds. As a result, while the Wye does not cause significant delay to operations, it does result in slower overall speeds that could result in longer cycle times. Scheduled run times through this area do include a 10% padding to account for fluctuations in the running times through the Oakland Wye. Running times at other key locations within the BART system are consistent with the scheduled run times; more information can be found in Appendix A2 (a separate document). A previous BART signal system headway and capacity constraint study (Systra, 2012) identified the Oakland Wye is critically important to BART’s current operations and future growth in train service. The underlying signalling is in general well designed, although does have some issues that need to be addressed. The Sequential Occupancy Release System (SORS) overlay, however, was found to have severe and excessive impacts, and in many locations is unnecessarily restrictive. The study found that “SORS could be made to be much less restrictive, and need not be as restrictive as the underlying signal system”.
  2. ↑ Mallett, Zakhary (September 7, 2014). "2nd Transbay Tube needed to help keep BART on track". San Francisco Chronicle. Retrieved July 31, 2017.
  3. ↑ Eric (July 23, 2008). "New Feature: BART Track Map". Transbay Blog. Retrieved July 31, 2017.
  4. ↑ "Automatic Train Control in Rapid Rail Transit" (PDF). Office of Technology Assessment. May 1, 1976. Retrieved June 14, 2017.
  5. ↑ "crawl speed through the Oakland Wye tunnels..." BART Rage. November 19, 2007. Retrieved July 31, 2017.
  6. ↑ Cabanatuan, Michael (30 January 2001). "Building a bigger, better BART / Experts suggest improving the current system before extending it". San Francisco Chronicle. Retrieved 9 December 2017.
  7. ↑ Cotey, Angela (July 2012). "Bay Area Rapid Transit's push to invest in state of good repair, capacity improvements". Progressive Railroading. Retrieved 11 December 2017.
  8. ↑ Cabanatuan, Michael (11 February 2000). "Improperly Fastened Power Cable Blamed for Horrendous BART Delay". San Francisco Chronicle. Retrieved 9 December 2017.
  9. ↑ Cabanatuan, Michael (4 February 2009). "BART trains on time, crash site to be cleared". San Francisco Chronicle. Retrieved 9 December 2017.
  10. ↑ Cabanatuan, Michael (5 February 2009). "BART operator ran past wait point in collision". San Francisco Chronicle. Retrieved 9 December 2017.
  11. ↑ "NTSB Launches Investigator to Bart Collision" (Press release). National Transportation Safety Board. 4 February 2017. Retrieved 9 December 2017.
  12. ↑ Cabanatuan, Michael; Veklerov, Kimberly; Ravani, Sarah (6 January 2017). "BART systemwide meltdown after train gets stuck in West Oakland". San Francisco Chronicle. Retrieved 9 December 2017.

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