Railway bridge loads 3

[MIKE_311]

I'm looking at a protentional redesign of rail bridge. The design calls for and EMD SD70 Locomotive, 33,700 Gallon DOT 112 Tank Car, and a Cooper E60.

AREMA only discusses design using the E80, the E60 is easy enough but I can't seem to find anything on the other two loads.

Sample calcs provided show that only the E60 was used.

Any guidance would be appreciated.

 

[SlideRuleEra]

The design calls for and EMD SD70 Locomotive, 33,700 Gallon DOT 112 Tank Car, and a Cooper E60.

...but I can't seem to find anything on the other two loads.

Base the design only on an appropriate Cooper E loading.
Find out what Cooper E loading the locomotive and tank car need. Both will have be designed by manufacturers so that full load is evenly distributed to all axles:

Per this reference, an EMD SD70 Locomotive weighs 394 kips and has 6 axles. Best possible (and also the most likely) case is an axle load of 65.7 kips/axle (394 kips / 6 axles = 65.7 kips/axle).

Per this reference, a 33,700 Gallon DOT 112 Tank Car weighs 263 kips and has 4 axles. Again, best possible and most likely case is an axle load of 65.8 kips/axle (263 kips / 4 axles = 65.8 kips/axle).

Since Cooper E60 is 60 kips/axle... Cooper E60 is not adequate. I suppose you could go to Cooper E70, but might as well conform with typical modern specs and go to Cooper E80.

 

[PEinc]

Nice response, SLR.

http://www.PeirceEngineering.com

 

[SlideRuleEra]

Thank you, PEinc.

 

[spsalso]

There is an SD70 series. One of the versions is the "base" SD70. There are about 15 others:

https://en.wikipedia.org/wiki/EMD_SD70_series

The SD70ACe-T4 is listed here:

https://www.progressrail.com/en/Segments/RollingStock/Locomotives/FreightLocomotives/SD70ACe-T4.html

at 428,000 pounds.

Weights can vary for specific models.


spsalso

 

[FacEngrPE]

https://www.thedieselshop.us/

has a table with 9 versions of the sd70.
Number of axles varies, as does the weight.

I like SlideRuleEra (Structural) recommendation. Even if not intended now, what keeps a modern day Cooper 80 load off of this structure?