San Francisco Railroad Accident Michael Murphy SYSM /25/12 San Francisco Railroad Accident Michael Murphy SYSM /25/12 San Francisco Railroad Accident Michael Murphy SYSM /25/12 San Francisco Railroad Accident Michael Murphy SYSM /25/12

 Serves approximately 35% of the entire San Francisco population.  Covers approximately 47 square miles.  7th largest transit system in the US, 2nd in California.  Consists of 506 buses, 313 trolley buses, 151 light rail vehicles lines, 40 cable cars and 40 streetcars.  Fleet average speed is 7 – 8.1 mph (slowest in US). San Francisco Railway Transit System (MUNI)

 Date: July 18, 2009  Time: 2:50 pm, Pacific daylight time  Property Damage: $4.5 million  Injuries: 48 (28 serious)  Accident: L train 1433 struck the rear end of standing K train 1407  K train was at the end (aka platform) of the West Portal Tunnel, waiting to merge onto the K line.  L train, controlled by automatic train control system (ATCS), pulled into tunnel.  L train operator “cut out” of ATCS to manually pull ahead to the platform.  L train was moving about 5 mph when the operator “blacked out” until impact.  Emergency pushbutton found not engaged  Throttle stick found in maximum power position San Francisco Railroad Accident

 Operators are to keep the trains on ATCS until reaching the West Portal platform.  Operators are to ask the Operating Control Center (OCC) for permission prior to switching from ATCS to manual mode.  OCC employees are to monitor when trains are switching from ATCS to manual mode. Notable West Portal Tunnel Requirements

Accident Simulation KL Tunnel Platform Inbound Outbound KL KA-BLAM!!! K Train arrives in tunnel, no cars at platform. K Train pulls ahead to platform. L Train arrives in tunnel, K Train still at platform. L Train changes to manual and pulls ahead to platform.

 Weather  NTSB determined weather had not limited visibility  Operator under the influence of drugs/alcohol  All tests came up negative  Track Defects  None were identified by NTSB after the accident  Train Malfunctioned  Operators claim trains operated normally and MUNI records indicated that the train equipment had been inspected and tested within the required intervals Human Error  L Train Operator failed to keep the train in automatic mode until reaching the station stop at the West Portal platform  Would have been a safe guard against his “black out”  OCC failure to monitor and enforce requirement that the operator wait until reaching the platform before changing operating mode of the train. Possible Causes of Accident

 2 days after the accident, the superintendent of train operations issued a bulletin reminding the train operators not to “cut out” of the ATCS without OCC permission. The final sentence of the bulletin read, “Failure to comply with these existing rules outlined in the Rules and Instruction Handbook will result in discipline, up to and including termination.” Corrective Actions Taken

 Corrective Actions only addressed the human error.  No system requirements were identified that prevent the human from making the error.  No system requirements were identified that prevent the trains from running into each other. Requirements Issues