Re: NNG Multiple fatalities in Tacoma WA Amtrak derailment

rehunn Wrote:
-------------------------------------------------------
> I would assume that unit has blended brakes where
> the dynamics assist in the braking effort. From
> everything I've seen and heard, I doubt that he
> ever went into
> emergency.

"Blended Braking" is the simultaneous use of automatic, dynamic, and a touch of engine brake (jam, driver brake). Blended is performed by moving the throttle to idle without bailing the locomotive wheels off. As the locomotive transitions into dynamics, the engine brakes are actuated off in relation to how much dynamic current is generated to prevent wheel slip. Slowing down using blended can be quick when compared to stretch braking, but...

I don't like using blended unless I have to, I find the slack a bit jarring, but I don't think anyone besides us on the front really notice. When I ran commuter, I would use it a lot. But running long haul trains, I prefer to bunch up using the dynamic, then supplanting with auto as necessary.

When it comes to the Talgo sets though with the only slack in the entire train being between the engine and the train, blended would be a nice way to go.

William Diehl... \M/( >.< )\M/
-Albuquerque
Big Diehl Photo <-Photos and Books For Sale, or Like it on Facebook.