The news reports continue to be confusing, as now they are claiming the engineer was not asleep (he was misquoted) but "in a daze". Since the engineer is under the threat of criminal prosecution by local officials, I wonder if he is talking freely to the NTSB/FRA or has lawyered up, and if his story is consistent. It is possible that he did have an unexpected medical condition that affected his abilities, and I will still leave the door open to a mechanical failure. I haven't heard the NTSB actually state that the cab car and engine event recorders are consistent with each other, but if they were it doesn't leave much but as the engineer's failure to properly control the train.

Another thing that has not been mentioned is if this was the engineer's regular assignment, or if he was off the extra board. The interesting thing about the hours of service rules is that they only require the railroad employee to be provided time off, and a place to eat and sleep if at an away terminal. To my knowledge, there isn't (yet) a federal or law that the employee be sufficiently "rested" when reporting for duty. I'm sure the engineer's health and off-duty activities will be the primary focus of the investigation if mechanical failure is not apparent.

Remember that the engineer and conductor are equally responsible for the safe operation of a train, but a conductor back in a passenger train doesn't always have an awareness of speed or location to fully fulfill that responsibility in regards to engineer oversight. Amtrak runs of less than six hours running time (the last I knew) and most commuter trains generally operate as engineer only in the cab, so there is not a second qualified employee to double cheeck the engineer. This fact is often overlooked when considering modern operating practices. The cab car should have had an alertor, but from first hand experience I can say that an alertor can help keep you awake, but it can also lead to a simple reaction to push the button to shut it up. I have also noted that alertors vary widely as to when they cycle, but at 70 mph+ I think they are supposed to cycle every 20-30 seconds in most systems.

I'm not familiar with the current hours of service for passenger. I know that after the Metrolink Chatsworth wreck Congress changed the rules for freight train crews (HOS is a law, not just a FRA regulation), but strangely passenger rules stayed the same but were eventually supposed to have changed. The elephant in the room that everyone refuses to admit to is that being on call 24 hours a day with no real expectation on when you might be going to work is never going to lead to anyone ever being properly rested when they do get called for work. Can you imagine if railroads had to give a 10 hour call for a pool crew? Or if an extra board employee had a standby window of 4 hours that they either would go to work or get another 8 hours off? HOS rules 2008 Passenger is now the same as freight?

Blended Braking - Never ran blended braking, but I am familiar with the basic theory. You will only find it in passenger service as it is unsuitable for controlling slack in a long train, and it is how the dynamic brakes can be controlled by a cab car. Remember that a non-dynamic brake equipped engine cannot control dynamics. In blended braking, when the engineer makes a brake application, the resulting brake cylinder pressure called for by the control valve is read by the system. Dynamics are used as the primary brake, and brake cylinder pressure is reduced to around 10 psi when dynamic braking is sufficient by itself. When dynamic brake is at capacity, the system allows brake cylinder pressure to build up to the appropriate level. At low speeds and higher speeds where the dynamics are less effecient or at capacity, the air and dynamics are "blended" to create the engine braking effort. If there is a dynamic or blended control failure, the system reverts to normal air brake control.

A couple of important points about blended brake - it only works if the throttle is in idle. And quoting a F40PH-2D operators manual: "Train handling must be planned so that the stopping distance of the standard automatic air brake system is sufficient to stop at the desired point in the event the blended brake system does not function". A shorted mu line or throttle control keeping the engine in power would explain excess speed and a lack of braking, but there was no stated brake application made and a timely emergency application would have tripped the PCS and reduced the throttle to idle.

Running out of fuel - bad idea for the obvious reasons. Also, running a loco low on fuel will cause them to suck the water and junk out of the bottom of the tank which will plug your fuel filters. Also, any water trapped in the filters can freeze and chokked off your fuel flow.

The news channels continue to be idiotic - one did a phone interview with an "expert" about passenger train safety - from the UK! Not to be outdone, the other network had one of their limey reporters talk about his own experience in a similar wreck years ago in Scotland.

UPDATE: NTSB news conference just said no apparent anomolies with the brakes and they reviewed cab car event recorder. Engineer was on second day, first leg of two round trips, regular assignment since mid-November.

Pure speculation - but it appears the engineer was either medically incapacited or for some other reason not properly controlling the train.