Railcar Operating Loads: Cargo Side Thrust Forces

[Altai]

Dear native English-speaking professionals!
I am making up an info table concerning railcar operating loads, and I’m a bit stuck with one term - I’m not sure if it sounds comprehensible enough to an Enflish speaking reader.
Here is the part I’m struggling over:

"Load description: cargo side thrust forces (N/mm2)"
"σ = stresses due to bulk cargo side thrust static pressure per unit area of carbody side, MPa."

What I’d like to know - is the phrase “cargo side thrust forces” comprehensible enough? Does it sound right? Or is there probably a better way to put it? Being no native English speaker, I’m not really sure...

 

[DickL]

I would use the term "lateral loading" rather than side thrust forces. Also, the lateral loading may be expressed as either a total load (n's) or an average load or pressure (n/m^2), depending upon how it is being applied/used. Lateral loadings may apply to both the cargo, or the car (empty or loaded) depending on what is being considered; the forces on the rails or the cargo restraints. Lateral loadings may come from transient or short term lateral dynamic actions due to track roughness or misalignment, or the longer term loadings due to curves.

If you are talking about liquid or dry bulk cargo, they will exert a hydrostatic load on the walls of the container. That loading will vary with height, so either a maximum or an average pressure would be applicable. Of course dynamic loading would also add to the hydrostatic loading.

Cargo loads are applied in all 3 directions, but generally due to different influences, and they can be transient or longer term. Typically maximum loadings are due to transient effects.

With respect to stresses, I would be cautious in defining a general stress as you've indicated. There are many load and location combinations that can be critical such that defining a kind of average stress may be misleading.

The above comments are coming from a design perspective, not from an operating instruction point of view. My rail background has been with passenger vehicles rather than freight, but I don't think that changes the design aspects that much.

 

[Altai]

Thank you very much for such a profound explanation! It really helps.