Western Railroad Discussion > Woodford derailment: switcher should have been 2nd out

In reference to the existing Woodford derailment threads, some random thoughts come to mind:

I think this is why SP always moved switchers on road trains as the second unit in the consist. There is way too much force on that little switcher caught between those big GEs and a heavy train.

Perhaps this remote is not weighted properly. Looks like a non-powered remote (no exhaust stacks) and maybe they removed the prime mover too... did they not add enough weight to this thing to bring it back to its original weight?

I wonder if the engineer will get pinched for using excess dynamic...
also wonder how heavy that train was...

Thoughts from afar...

Sac
Bangkok, Thailand

Fair call - that light weight locomotive would either move laterally under increased run-in-forces or even tend to "lift" vertically to a degree with the run-in forces of the train.

Mike

wonder if the coupler stops (limits lateral travel) were in place. Too much buff if your are in a sharp curve....and you are gone...over the high rail

None of this makes any difference in a derailment caused by a loose wheel on a locomotive.

The odds of one of the wheels being loose on the 3403 are very, very slim. In my railroad career, I've never seen a wheel that came loose from the axle but I'm sure it's probably happened.

I don't know what restrictions, if any, are in place on the BNSF when hauling a switch engine in a consist but I think they should think about something like that if they don't have anything.

steamjocky

Steamjocky Wrote:
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> The odds of one of the wheels being loose on the
> 3403 are very, very slim. In my railroad career,
> I've never seen a wheel that came loose from the
> axle but I'm sure it's probably happened.

Isn't that what happened on Amtrak's ill-fated SDP40F's that got them restricted speeds on many lines?

Well, I talked to a couple guys who saw the train go through Walong; they said that the trailing truck was smoking and sparks were being thrown. I am not sure how these things work with traction motors, etc... But it seems like the axle locked-up or something and this caused the wheel to come off the rail. By the time I saw it, the wheel was on the ground. I would be interested in seeing what the actual cause was and how long the wheel was on the ground.

Fo those of you familiar with Tehachapi, what kind of defect detector is just RR north of the Loop? It is listed as a talk-on-defect only detector. Is this a hotbox or dragging detector?

BJR

sjh92705 Wrote:
-------------------------------------------------------
> Steamjocky Wrote:
> --------------------------------------------------
> -----
> > The odds of one of the wheels being loose on
> the
> > 3403 are very, very slim. In my railroad
> career,
> > I've never seen a wheel that came loose from
> the
> > axle but I'm sure it's probably happened.
>
> Isn't that what happened on Amtrak's ill-fated
> SDP40F's that got them restricted speeds on many
> lines?


No. It had to do with the trucks.

steamjocky

BJRubino Wrote:
-------------------------------------------------------
>
>
> Fo those of you familiar with Tehachapi, what kind
> of defect detector is just RR north of the Loop?
> It is listed as a talk-on-defect only detector.
> Is this a hotbox or dragging detector?
>
> BJR


There is a dragging equipment detector at the signal between Woodford and Walong at MP350.6 that is activated only when it detects something dragging.

steamjocky

Believe the problem with the Amtrak SDP40F's was called "vibratory yawing", hunting of the trucks especially on jointed track at high speed. -- -- -- -- -- JLH

The Amtrak SDP40Fs had several things happening regarding the derailments on several railroads:

1) The SDP40F contained a large water tank in the top of the carbody at the rear end. When the water in the tank had been partially depleted by the steam generator, the remaining water would "slosh" back-and-forth sideways. The "sloshing" movement of that large weight of water added to normal side-to-side carbody movement.

2) The derailments of concern typically happened when the rearmost SDP50F was operating nose-forward and was coupled to a baggage car, which was typically a very light passenger car.

I believe the derailments were usually started when the leading wheels on the baggage car's front truck derailed first, because the rear end of the trailing SDP40F and the front of the baggage car were moving back-and-forth sideways as the train traveled down the track. That motion eventually resulted in a baggage car wheel flange climbing over the rail.

highgreengraphics Wrote:
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> Believe the problem with the Amtrak SDP40F's was
> called "vibrational yawing", hunting of the trucks
> especially on jointed track at high speed. -- --
> -- -- -- JLH


You are correct, oh great one. This is why on certain curves the locomotives were restricted to 50mph.

steamjocky

Switchers or for that matter any locomotive that has not been fitted with alignment control couplers are usually placed secon in consist
This happens regularly on trains out of West Colton.

Andy G

BNSF's former BN SW1000 and SW1500 units are not equipped with alignment control couplers. IIRC some of the SD9's are not equipped either. Can check a BN/BNSF special instructions for info on which units are not equipped with ACC.

Regards
Q-GP30

Yes John ran these engines on the coast before the f40's.. restricted to 50 mph on curves over 1 degree.. Tommy McDonald (MAster Mecanic) .rode with me from Santa Barbara to LAUPT. to see the problem with the units. on these curves .i had to adhere to the 50 mph limit on the curves.. I never worried about the restiction nor did any other engineers..except with him watching the speedometer... the Coast Dispr was wondering how did i lose so much time between Santa Barabra and Oxnard on this particular trip!

On the SP, there could be no more than two SW-1500s in the consist and they had to be second and third. There were some couplpler stops you had to put in too.

The speed limit on the ATK 500s was lifted when the shock absorber was added to the middle axle of each truck. This 50 mph restriction applied to any locomotive equipped with these trucks (like the SP 9200s--SD045s). Still does.

Thanks to all for the detailed info on the Amtrak SDP40F problems. It's been so long since they were around, but it was interesting to learn all the little details!

Steamjocky Wrote:
-------------------------------------------------------
> The odds of one of the wheels being loose on the
> 3403 are very, very slim. In my railroad career,
> I've never seen a wheel that came loose from the
> axle but I'm sure it's probably happened.
>
> I don't know what restrictions, if any, are in
> place on the BNSF when hauling a switch engine in
> a consist but I think they should think about
> something like that if they don't have anything.
>
> steamjocky


I don't think Rollin was speculating on the cause - and he just MIGHT have inside information <LOL>!

Railfool03 Wrote:
-------------------------------------------------------

> I don't think Rollin was speculating on the cause
> - and he just MIGHT have inside information
> <LOL>!

Yup. I'd never doubt him on anything!

UP lists the primary cause of the derailment as being a mechanical defect on the switcher (well, I guess it's really not a switcher anymore), with the secondary cause being that it was improperly entrained in the locomotive consist (should've been placed second out).

"that light weight locomotive would either move laterally under increased run-in-forces or even tend to "lift" vertically to a degree with the run-in forces of the train."

Worse than the first car behind the power ???

The reason SP (and CP) and probably others moved some yard engines as the 2nd unit of the consist is the lack of alignment control couplers.

CP had a major wreck in Toronto due to this and the "2nd up" rule came in after that for non-ACC equipped units.