so I've mostly done scenarios with the helper units going one way on SPG, but coming the other direction I loaded up an AC4400 service with only two locos at the front, the second one being an SD40, and AFAIK set everything up correctly from the start in the lead loco as I usually do, it's basically second nature to me right now to start most services (brakes cut in and lead, switch the switches on, reverser in forward, remove brakes, apply throttle) but the fact I'm not getting over 16mph suggests that the second loco is dead weight. looking at all the controls inside it, it seems set up the way a second unit is normally set up in an SD40 pair, which always works fine on those services (trail, cut out, handle off, no reverser handle, gen field off), so I don't know what I need to do differently if the lead unit is a different loco. Is there something different to usual I need to do for this mismatched pair to have them both work? Something that's not usually turned on which needs to be? Or the trail option changed or something? It's probably super obvious but has got me stumped.
Did you actually check the set-up of the SD40? For clarity’s sake: 3 switches all off reverser removed brakes cut out MU-2A valve in Trail 6 or 26 (best to switch it to something else and then back if it already starts in the correct position) If all of that was set up correctly and the issue still persists, then the train was likely underpowered with an SD40. Service number, train weight, etc would be helpful.
Yeah, SD40s as the second unit always start the run on every route configured with engine run and fuel pump on, generator field off, reverser out, handle off cut out trail 6 or 26, which usually works just fine if the leading unit is also an SD40. I tried toggling engine run and fuel pump off but that changed nothing, I'll try restarting the run by toggling trail to 24 and back to 26
Curiously, when I backed out of the scenario and started it from the menu instead of restart - the second locomotive is also an AC4400 instead of an SD40 - so I am guessing that was bugged, and the service isn't supposed to have a Clinchfield SD40 there
No, your trailing loco is randomly chosen from the substitution pool. So it’s not a bug to have an SD40.
Fair enough .The 4400 started out configured correctly though, so everything ran smoothly. Next time I try one and it picks an SD40, I'll try out the recommendation of toggling trail back and forth.
There are some consists which 7400 hp just can't drag up the hill. The rule of thumb is total hp/train weight >= maximum % grade on the route. Mind you, that means enough traction to get up the hill at all, not necessarily to do it fast. Certain consists get down to about 18mph... The red flag that tells you that you just don't have enough oomph is if the ammeter redlines and you have to reduce throttle. This is usually the beginning of a power death spiral.
What about Clinch field Greenbriar Branch? Couldn't get it past the stop light after the train cleared.
Hill starts are tricky. In general, you want to (a) set the independent brake to full application, to hold the train, (b) release the train brake and let it release fully, all the way back, (c) rev the engine (Run 3 is usually about right; don't go too high or you'll get wheelslip), (d) release the indy brake, and apply sand.
