Arosa Line Coaches Unrealistic Behavior On 6% Grades.

I tried testing one of the arosa coaches to see if it would roll downhill on the route steep grade and it just will sit on the 6%grade and not move even with the brake wheel fully off(BTW do the coaches brakes even work/or the just for pretend use)So if your train needs to be carefully braked while going downhill or up,then why would a single car not move at all while being solo on a 6% grade?

 

I think you'd need a loco attached to create a vacuum, otherwise the brake shoes will stay on and it won't go anywhere?

 

No, you need a loco to "release" the vacuum brake on the coach so that the brakes release...
Vacuum brake - Wikipedia

 

It depends on how realistic the brake system is modelled in TSW. The RhB uses a vacuum controlled air brake, which means that the brake cylinder is powered by compressed air but the control valve is actuated by a vacuum. That's why RhB rolling stock you will find two different air hoses.
If this is system is modelled completely accurate in TSW you might see the coach starting to roll after a while, because the air pressure leaks out of the brake cylinder.

 

That's really interesting. Do you know why they choose to do it this way?

 

Originally they used normal vacuum brakes. These had multiple advantages to air brakes at the time. Air brakes could only be applied in steps, but not released. This means you could always increase the brake pressure but to decrease it you had to release the brakes completely. For a mountain railway with very steep grades, this is rather unpractical.
Air brakes also loose pressure when you adjust them to often (brake fanning), which is not the case with vacuum brakes.
Another advantage of vacuum brakes is a finer control of the brake pressure.
But vacuum brakes developed much less brake pressure than air brakes. Air brakes usually reach a pressure of 3,8 bar whilst vacuum brakes are only able to reach 0,7 bars. For the same braking force you need much bigger cylinders with vacuum brakes.
Also you can't implement a mechanical wheel slipe protection with vacuum brakes.
With combining these two systems the RhB has combined the advantages of both systems into one. This also had the advantage of having a smooth transition to the new system. Both systems can be more or less used in parallel without the need to convert the entire rolling stock in on go.

 

Thanks for that, very enlightening! I suspect whatever is modelled in TSW will be of reduced complexity regarding how the brakes are actuated and without a loco to draw them off the coach will remain stationary. More experimentation needed...