Railworks America

Looks like the Driver used up all the brakes. Serves him right!

Silver Steak with Gene Wilder comes to mind on that one.

People always say when a train wrecks it "lost its brakes". Whatever happened to dynamic brakes until it slows enough that the independent cans stop it? I've heard a lot about that on cajon pass wrecks.

Drivers just don't think to use the Dynamics

1225fan5358 wrote:People always say when a train wrecks it "lost its brakes". Whatever happened to dynamic brakes until it slows enough that the independent cans stop it? I've heard a lot about that on cajon pass wrecks.

Uhmm....well there is a such thing as burning the grid out. Dynamic braking is the result of the traction motors trying to stop the wheels from turning, they can only do so much before they fail. No doubt that train on Cajon that wrecked would have burned it's out.

Something is telling me not to touch this one with a 39.5' pole, yet I cannot resist.

I just want to point out the fact this incident was in a yard and dynamics would have done nothing...

Imagine the relief. So so close to going down.

There are several reasons why the train might have lost it's brakes in a situation like this. IMO it's improbable that he used up all the air, given that the approaches to LAUPT aren't all that heavily graded. Clearly, speed was not an issue since the damage to the pilot is minimal and the first unit didn't break through as far as the fuel tank. Dynamic brakes wouldn't have helped, because they tend to drop out as the train slows. In those days, they were regarded as ineffective below 5mph. You've got me curious enough to see whether I can find the accident report ...

(EDIT): There's no ICC accident report in the archives, which would suggest to me that this was probably a yard movement of an empty train. It's possible the yard crew lost track of where the other end of the consist was until it became to sluggish to push. Given the presence of L.A.'s finest, there was probably a police report on it, and there may have been a California Railroad Commissioners' report as well, but I'm not aware of any online archives for either of these, particularly for reports that far back.

FourEightFour wrote:Something is telling me not to touch this one with a 39.5' pole, yet I cannot resist.

I just want to point out the fact this incident was in a yard and dynamics would have done nothing...

Then how did he get the speed to break through the wall and bumpers? Something tells me 15 mph would do that.

Dynamics quit being effective around 20MPH. Especially on 1st generation diesels.

As for the San Berdoo incident with SP, that was because he big holed the train, and the PCS Switch opened and thus deactivated the dynamic braking.

^^ the conductor in one of the helpers dumped the air in that accident, causing the PCS to kill the power to the traction motors. Which is now why there is a gap time between PCS open and power cut out.

Dynamic brakes operate off something totally different than air brakes, would have been nearly useless in that situation of the F unit going thru LAUPT.

trkspd wrote:^^ the conductor in one of the helpers dumped the air in that accident, causing the PCS to kill the power to the traction motors. Which is now why there is a gap time between PCS open and power cut out.

Dynamic brakes operate off something totally different than air brakes, would have been nearly useless in that situation of the F unit going thru LAUPT.

Forgot the detail on the conductor, yes. Thats what I was getting at.
As I said, Dynamics are only effective until around 17 MPH on first generation diesels. About 11.4 on newer ones, and 5.5 on ones with extended range dynamic braking.