Train Tonnage - Northwestern Pacific Railroad Network2024-03-28T08:53:02Zhttp://nwprr.net/forum/topics/train-tonnage?feed=yes&xn_auth=noThat's why you put the DPU's…tag:nwprr.net,2013-04-04:3290209:Comment:965942013-04-04T04:02:49.867ZJordanhttp://nwprr.net/profile/jordanism22
<p>That's why you put the DPU's in asynchronous control when cresting a hill. Have them keep applying power while the head end units are in dynamics.</p>
<p>That's why you put the DPU's in asynchronous control when cresting a hill. Have them keep applying power while the head end units are in dynamics.</p> Only with poor memory from ye…tag:nwprr.net,2013-04-04:3290209:Comment:963352013-04-04T03:37:12.386ZJim McCarterhttp://nwprr.net/profile/JimMcCarter
<p>Only with poor memory from years back do I think I heard that there was a concern of pulling a heavy train apart and also could occur as the head end was going down while the rear was going up. That could be more so if the engineer applied too much power on the down side. I would guess that is why mid or rear end helpers and also carefull where to put helpers that are added for dynamic braking. Seriously, pretty complex and way beyond anything I know. Once again, thanks</p>
<p>Only with poor memory from years back do I think I heard that there was a concern of pulling a heavy train apart and also could occur as the head end was going down while the rear was going up. That could be more so if the engineer applied too much power on the down side. I would guess that is why mid or rear end helpers and also carefull where to put helpers that are added for dynamic braking. Seriously, pretty complex and way beyond anything I know. Once again, thanks</p> Just thought this was interes…tag:nwprr.net,2013-04-04:3290209:Comment:965092013-04-04T02:08:07.574ZJordanhttp://nwprr.net/profile/jordanism22
<p>Just thought this was interesting since people here like to reminisce about the days of 8-10 SD9's tackling Ridge Hill with a monster train. Two, yes two ES44AC's can pull an 85 car 7,000 ton freight south over Ridge and maintain about 13 mph. The drawbar max for Ridge is 4700 tons, so one would have to run as a DPU, but two is all you would need. Going north up the 3% grade hey would make about 8 mph. I'd throw in a third unit going north if I were in charge, in a 2x1 configuration.</p>
<p>Just thought this was interesting since people here like to reminisce about the days of 8-10 SD9's tackling Ridge Hill with a monster train. Two, yes two ES44AC's can pull an 85 car 7,000 ton freight south over Ridge and maintain about 13 mph. The drawbar max for Ridge is 4700 tons, so one would have to run as a DPU, but two is all you would need. Going north up the 3% grade hey would make about 8 mph. I'd throw in a third unit going north if I were in charge, in a 2x1 configuration.</p> Oh, I got this etched deep no…tag:nwprr.net,2013-04-03:3290209:Comment:964462013-04-03T16:17:50.288ZJim McCarterhttp://nwprr.net/profile/JimMcCarter
<p>Oh, I got this etched deep now!! LOL All I can say is that I really did know the railroads have this all figured out. I still like your formula for horsepower per ton x12 divided by grade etc. Although general it does kinda of help with NWP and guessing when they might need more than one unit. Engineering is complex. Simple tire size on a vehicle is by engineering (weight, horsepower, ground pressure per inch of tread, conditions) and thats why most people don't really know what they are…</p>
<p>Oh, I got this etched deep now!! LOL All I can say is that I really did know the railroads have this all figured out. I still like your formula for horsepower per ton x12 divided by grade etc. Although general it does kinda of help with NWP and guessing when they might need more than one unit. Engineering is complex. Simple tire size on a vehicle is by engineering (weight, horsepower, ground pressure per inch of tread, conditions) and thats why most people don't really know what they are doing when they change a tire size. Point is, the more you learn about something, the more you realize you don't know. Thank you very much for taking the time to post.</p>