Does anyone know how different railroads decide how many locomotives to allocate to trains? Specifically, at what point does a railroad decided that 2 locos grinding up a steep grade at walking pace need a third loco or helpers to get over a mountain quicker/more efficiently?
I'm particularly interested in old Conrail operations and have found an excellent blog by a former employee.
Compare that with Horseshoe Curve operations where there are several locos on the front of train and a couple of helpers on the rear.
This is all information I'd like to incorporate into my own Trainz WIP mountain route. I can run heavy trains on 1.5 to 2.0 per cent grades but seem to need more locos than what the prototype would use. I'm not sure Trainz would be able to come close to replicating this test:
Cheers
Hiyo
I'm particularly interested in old Conrail operations and have found an excellent blog by a former employee.
We ground up another hill at full throttle and 8 mph. I could jog faster, but it was quite a show listening to the locomotives work up the grade. The EMD was blasting out it's high pitched turbo whine accompanied by the sharp, bass "whop, whop, whop" of the C36-7 trailing. The SD50 had EMD's new Super Series adhesion control and the GE had their response - Sentry Wheelslip Control. Both worked well as the locomotives maintained a good grip on the rail as the load meter moved steadily upward and edged into the red. We crested the grade had then braked down the other side. http://blerfblog.blogspot.com.au/2014/08/war-stories-episode-23-how-to-scare.html
Compare that with Horseshoe Curve operations where there are several locos on the front of train and a couple of helpers on the rear.
This is all information I'd like to incorporate into my own Trainz WIP mountain route. I can run heavy trains on 1.5 to 2.0 per cent grades but seem to need more locos than what the prototype would use. I'm not sure Trainz would be able to come close to replicating this test:
The test consist included the three SD60MACs, EMD's test car, and 110, 100 ton hoppers. Trailing tonnage was 14,700 tons. The destination was Enola where these 110 car trains were chopped down to 90 car trains in order to operated south through the B&P tunnel to power plants in Maryland. The train was right at the limit for tonnage on the west slope, so we had a pair of helpers tacked on the rear at Conemaugh for safety. Started to pull. Not moving. Dynamometer coupler in EMD's test car was showing less 100,000# per unit with quite a bit of variability. Lead unit is jumping up and down a bit. EMD advises the engineer to trust the wheel creep system and just keep pulling. Slowly, we start to move. After 12 minutes, we're only a few hundred feet down the track. Still not pulling anywhere close to 35% adhesion. http://blerfblog.blogspot.com.au/2014/08/war-stories-episode-26-emds-travelling.html
Cheers
Hiyo