by minerman146 » Mon Apr 06, 2020 2:53 pm
Thor - good question and thank you!
What we were trying to replicate was 2 things.
1. Service Quadrant
2. Electric Hold
In the previously posted image of the brake handle we had 5 positions: Release, Electric Hold, Lap-handle off, Service and Emergency.
The only "notch" where brake application starts is as Service. Moving the handle past service starts to release air and you make an application. The service position itself is at 60-65% on the HUD handle. So, you could park the handle at 59% with out any application being made, then pushing the handle further to the right you could make a reduction of 5, 10, 15lbs and so on. To use electric hold (which I believe is like LAP), you make a reduction say of 10lbs, then pull the handle back to the Electric Hold position and leave it there. What you get is a continuous 10lb brake AND the air is recharging. If you wanted to add more air to the application you go the Service Quadrant, and add more pounds. To release and use the brakes 'normally' you go all the way back to release and then past Service to make a regular, non-electric hold application.
Our issue was that setting the brake like this - we lost notches and you had to find the service quadrant by eye (at 59%) on the HUD, and then pull the handle back, really anywhere between 20-50% on the HUD. AND because the brakes were not NOTCHED we couldn't label the HUD to show "EH, LAP, SERV" and so on - it was just %. And lastly - we couldn't get this to translate at all to the brake on the Cab Car. I was way way beyond my ability at that point - and started asking for help here. In the end we had to scrap the idea. My father said what we had was the closest to the way the brakes were supposed to operate. What he wanted was notches so the handle would rest in each position - the labels and % were meaningless to him. (and he has train simulator, I was watching his session remotely and speaking to him on the phone while he ran tests)
If you get bored and want to do my test run - Get on the Bergen going West starting at Plauderville ... get the speed to 60 MPH, bring the handle forward to 80% at take off 20lbs (watch the brake pipe gauge) at 50 seconds from the Fairlawn Station
then pull back to 25% it should hold at 20lbs. But this is how you can fake it with the as released version. And its very fiddly, it took me 3 tries to do it before I posted this.
Regarding implementing this - a volunteer came forward to take a stab at it, he has the version (#32 of 42) and the code. I would suspect it will take him at least a week to determine if he can do it, if, at all.
In my opinion, after HEP, the Electric Hold function is what makes the U34CH the U34CH.
"In business, I prefer to keep company with honest men, so I ship on the Erie"