S turns and light weight cars in front

[Terry Toenges]

The same principle applies to model railroading.

[WiriliBL]

 

[Len]

There's a prototype out there for almost everything we model.

Len

[trainman203]

Except.  Why the rear most derailed cars turned outward?  Maybe this was the rear of the train and the derailed locomotives were pushers.

That is one really sharp curve for the prototype, looks like on a layout almost.  What are all those horizontal things on the ground that look like another track? Welded rail laying on the ground?

[jward]

Except.  Why the rear most derailed cars turned outward?  Maybe this was the rear of the train and the derailed locomotives were pushers.

That is one really sharp curve for the prototype, looks like on a layout almost.  What are all those horizontal things on the ground that look like another track? Welded rail laying on the ground?

This is a classic stringline derailment.The train tried to straighten itself out on the S curve. Like Terry said, empty cars in the front with a heavy train behind it. The weight of the train pulled the empty flat off the rails. This caused a chain reaction that derailed other cars. Notice the derailment happened on the inside of BOTH curves.

Had this been a case where the helper locomotive caused the derailment it would have looked much different. Instead of the train trying to run a straight line when it left the rails, it would have piled up due to the compression forces in the train ahead of the helpers. You would have had twice as many cars on the ground and they would have went everywhere, over the hill, on top of each other, etc. It would have been a jumbled mess instead of the relatively orderly derailment seen here.


Stringline derailments have become more common in recent years with the railroads obsession with running ever longer trains with fewer locomotives.

[Len]

Whoever set the car order with all those light cars in front shares at least some of the blame on this one. Maybe the RR training department needs to set up a layout with a 'S' like the one in the pic to explain why doing that is not a good idea.

Len

[Terry Toenges]

It's from this guy's post on the If You Worked on the Railroad Facebook page. scroll down to about 3 days ago.
https://www.facebook.com/groups/658047340912711/user/100004926425617/