Slashdot Mirror
TGV Accident Caused By Excessive Speed (railwaygazette.com)
Cochonou writes: Analysis of the black boxes of the TGV (Train à Grande Vitesse) which derailed on Saturday revealed that the accident resulted from excessive speed and late braking. The test train entered a 945m-radius curve at a speed of 265 km/h, far over the maximum speed of 176 km/h. The French national railway company ruled out any other cause, such as mechanical failure or track mishap.
During test runs, a number of security features are disabled, in particular parts of the TVM system, which would have prevented any overspeed during normal service. This leaves the train speed under the sole responsibility of the driver.
The accident, which killed 11 people, occurred on the last run of the scheduled trials on the new high-speed line between Paris and Strasbourg. As more details on the accident surface, it becomes evident that this last run was performed in a festive spirit, with relatives (including children) of the employees on board, and seven people present in the train cab instead of train. This casts a shadow on the security procedures of the French national railway company: it appears that the high-speed train technology is considered so safe that the risks inherent to trials runs were somehow neglected. The two drivers and the traction inspector have been suspended pending possible criminal charges. Other changes in the management structure will probably follow.
During test runs, a number of security features are disabled, in particular parts of the TVM system, which would have prevented any overspeed during normal service. This leaves the train speed under the sole responsibility of the driver.
The accident, which killed 11 people, occurred on the last run of the scheduled trials on the new high-speed line between Paris and Strasbourg. As more details on the accident surface, it becomes evident that this last run was performed in a festive spirit, with relatives (including children) of the employees on board, and seven people present in the train cab instead of train. This casts a shadow on the security procedures of the French national railway company: it appears that the high-speed train technology is considered so safe that the risks inherent to trials runs were somehow neglected. The two drivers and the traction inspector have been suspended pending possible criminal charges. Other changes in the management structure will probably follow.
What resistor is that? Please elaborate.
I know a bit about signals and I know of no such resistor. The equipment and control logic for US signal systems are fail-safe designs, based on the standard AREMA guidelines and any failures will cause the signals to go all red.
None of them can see the clouds; The polished wings don't care.
It's not automated first because they're operating outside commercial speed envelope (they're authorized to overspeed as munch as 10% over commercial speed limit to check engineered margins actually exist) and second because those new tracks are often used with new hardware, and new hardware can have bugs that require emergency human action to avoid crashes. Therefore the test protocol gives maximum freedom to the engine operator.
(likewise new planes are tested by test pilots outside normal envelope, except trains need a track to run, track is too expensive to be dedicated to tests in any meaningful length, so tests are conducted on new track before it's commercially used. If you look at train speed record on wikipedia you'll see they were all achieved on new track just before it was opened to commercial service, for similar reasons)
The problem is that this was the final test run (meaning all the previous tests were successful, or more tests would have been scheduled), on hardware marginally improved from previous models with excellent safety record, during a week-end, and the test team treated it like a private risk-less celebration and forgot they were operating with safeties off.