The Crash of Two Subway Trains on the Williamsburg Bridge

1. The Crash of Two Subway Trains on the Williamsburg Bridge June 5, 1995 New York City, New York John B. Hamilton SE 6361 Z01 Advanced Requirements Engineering Fall 2012, Instructor Dr. Lawrence Chung Ph.D.

2. The Williamsburg Bridge is a suspension bridge across the East River connecting the Lower East Side of Manhattan at Delancey Street with the Williamsburg neighborhood of Brooklyn on Long Island at Broadway near the Brooklyn-Queens Expressway (Interstate 278). It is among of the three bridges to use Non-flexible type of towers. The other two bridges are the Brooklyn Bridge and the George Washington Bridge. The main cables of the Williamsburg bridge were spun by John A. Roebling Sons inc. Same company spun cables for the superb Manhattan Bridge and the great George Washington Bridge. Since the wires in the main cables in the Williamsburg Bridge are not galvanized the bridge engineers have had a problem in terms of protecting them from corrosion.

3. The Williamsburg Bridge opened in 1903, but construction began seven years earlier in 1896. It cost about $24,200,000 to build, and, at the time of its opening, it was the largest suspension bridge on the earth. (A suspension bridge is a type of bridge where the "deck," or lower part, is held up by cables or suspenders). The bridge has always run traffic, both cars and railway (these rails once belonged to the railroad; they now belong to the J,M,Z subway lines) and in the 1980s it underwent dramatic reconstruction when it was noticed that its floor beams had corroded. The Williamsburg Bridge celebrated its 100th birthday in 2003, and it was named a National Historic Engineering Landmark in 2009.

4. The Williamsburg Bridge, as seen from the Empire State Building

5. Williamsburg Bridge spanning over the East River in New York City

6. Construction of the elevated line from the Williamsburg Bridge, 1903.

7. In 1898, New York, Kings and Richmond Counties, and parts of Queens and Westchester Counties and their constituent cities, towns, villages and hamlets were consolidated into the City of Greater New York. During this era the expanded City of New York resolved that it wanted the core of future rapid transit to be underground subways, but realized that no private company was willing to put up the enormous capital required to build beneath the streets.

8. The subway system began during the “War of Currents” when Thomas Edison and his opponent, Nikola Tesla, struggled over acceptance of direct current or alternating current as the standard way to deliver electricity. Alternating current became the standard for non-railroad purposes, but New York City Subway adopted direct current as more suitable for urban railroad purposes. To this day, the New York City Transit Authority converts alternating current to 600 volts direct current to power the trains, as do most earlier and later local transit railways around the world.

9. MTA subway map, zoom on Manhattan-Brooklyn line

10. J Line Subway Train crossing the Williamsburg Bridge, New York City

11. Williamsburg elevated M train

12. Equipment In Use Some areas of the NYCT signal system, including Williamsburg Bridge, were installed in 1918. The average spacing between signals throughout the NYCT system is about 350 feet; the average spacing between signals on Williamsburg Bridge is 265 feet. The design of about one-third of the system was based upon acceleration and braking capacity of the R-9 car, which was built before 1948. The R-40 car is capable of speeds up to 55 mph and the R-9 car could attain a maximum speed of 27.9 mph. The J train had all R-40 series cars; the M train had all R-42 series cars.

13. Routes of the J train and the M train The operator and conductor of the New York City Transit (NYCT) southbound 531 J subway train went on duty at 11:38pm June 4, 1995. The M train departed on time at 5:48am June 5, 1995 from Metropolitan station. As it approached the Williamsburg Bridge, the M train was following a work train, which it usually did not do on its morning runs. The M train operator had to stop repeatedly to wait for the work train; however, he failed to radio and inform the command dispatcher of his stops as required by the NYCT's operating rule book.

14. The M train was stopped at Signal J2-120 when the J train proceeded past a Yellow caution light at Signal J2-130 travelling at 34-36 mph.

15. Although the automatic trip arm at red Signal J2-128 properly activated the emergency braking of the J train, it failed to stop within the 270-foot long block and struck the rear of the M train, which was 16 feet beyond Signal J2-122. The R-9 model car had a stopping distance of 170 feet whereas the later R-40 model required more.

16. Despite the proper activation of the trip arm and the train's emergency braking, the distance between signals J2-128 and J2-125 was not sufficient for the J train to stop safely and it struck and penetrated the rear of the M train. The J train operator was killed in the accident.

17. Interior damage to the lead car of the J Train

18. The Injuries The number of casualties from this incident was low because the crash occurred early in the morning. An hour later, the two trains would have been packed to capacity with rush hour commuters on their way to work in Manhattan. There were only about 200 passengers on the two trains at 6:12am. At capacity, there could have been more than 4000 passengers on board. It is fortunate that the crash occurred when it did.

19. Analysis From personnel statements, inspection reports, and post accident examinations, The National Transportation and Safety Board (NTSB) concludes that the track, the train equipment and the signal system functioned as designed. Weather and visibility were not factors. Witnesses stated that it was clear and sunny. Results of post accident toxicological tests indicate that the J train operator was not impaired by alcohol or drugs. He reportedly was in good health and was an experienced and qualified NYCT train operator.

20. Probable Cause The National Transportation and Safety Board (NTSB) determines that the probable cause of this accident was the failure of the J train operator to comply with the stop indication because he was asleep and the failure of the train to stop within the block because of inadequate braking distance between signals on the Williamsburg Bridge. Contributing to the accident were the New York City Transit’s inadequate measures for ensuring employee compliance with proper radio procedures.

21. Recommendations Develop a fatigue educational awareness program and distribute it to transit agencies to use in their fitness-for-duty training for supervisors and employees involved in safety-sensitive positions. The estimated cost of the installation of computer-based signaling on the entire NYCT system will cost $3.6 billion and take about 50 years.

22. Credits National Transportation and Safety Board (NTSB) Railroad Accident Report Federal Emergency Management Agency (FEMA) Technical Rescue Incident Report http://www.wikipedia.org/