Monday, July 20, 2009

NTSB says control at issue in San Francisco accident

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A National Transportation Safety Board investigator says it appears that the operator of a San Francisco Municipal Railwa (MUNI) light rail car switched fromautomatic to manual control just prior to a crash injuring 48 passengers. The train operator also was injured; none of the injuries was considered life-threatening.

The accident occurred July 18 as a westbound L train struck a K train that was sitting at a boarding platform in the West Portal Station, the western end of MUNI’s busy, underground LRT conduit running beneath the city’s Market Street. Investigators have found that the L-Taraval outbound train was switched from automatic to manual mode while still inside the tunnel approaching the platform. Normal MUNI procedure is to wait until the train enters the station to switch to manual.

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The MUNI operator reportedly told investigators he blacked out shortly before the accident.

This incident is the latest of several rail accidentsoccurring in recent weeks, including an accident May 9 involving two Massachusetts Bay Transportation Authority (MBTA) Green Line light rail transit trains that injured 49, and the deadly crash June 22 on Washington’s Metro RedLine, resulting in nine fatalities.

In the MBTA incident, the operator was suspected of text messaging against regulations, similar to the suspected actions of a Metrolink engineer last September, among the dead after his train ran a red signal and crashed into a Union Pacific freight train in Chatsworth, Calif.

A flaw in the automatic train control system, not operator error, appears the likely cause of the Washington MetroRail crash.