SD70Dude Pretty much all of CN's road units built or rebuilt since the mid-1990s have rear ditchlights. Some of them even work properly when MU'd with other units. For some reason ($$$?) they recently stopped ordering rear pilots on new units, which limits them to 25 mph when that end is leading a movement.
Pretty much all of CN's road units built or rebuilt since the mid-1990s have rear ditchlights. Some of them even work properly when MU'd with other units.
For some reason ($$$?) they recently stopped ordering rear pilots on new units, which limits them to 25 mph when that end is leading a movement.
10000 feet and no dynamics? Today is going to be a good day ...
Overmod BaltACD False assumption - what power is currently available that can move the tonnage to be moved in a On Time timeframe is the only consideration that is applied. I presupposed in saying 'assesses what power to use' that whoever was making up the consist would do so from the power available to him. I'm a bit surprised that CSX wouldn't be at least cognizant of keeping cabs available in case of road failure -- whether that's having the engine behind the point 'elephant-style' or arranging DPU to run around the train to lead 'cab-first'.
BaltACD False assumption - what power is currently available that can move the tonnage to be moved in a On Time timeframe is the only consideration that is applied.
I presupposed in saying 'assesses what power to use' that whoever was making up the consist would do so from the power available to him.
I'm a bit surprised that CSX wouldn't be at least cognizant of keeping cabs available in case of road failure -- whether that's having the engine behind the point 'elephant-style' or arranging DPU to run around the train to lead 'cab-first'.
Remember - CSX loads trains to MAXIMUM TONNAGE - failure of one engine brings the train to a halt - hopefully not in the middle of a single track segment. If the failure is in a single track segment - another train will use its power, in addition to the failed train's power to move it to a siding to await a 'final solution' to its power issues. The 'go to' solution is to steal an engine from a empty traing (coal, ethanol, oil or any other empty unit train that is running with more than a single unit).
The standard power, when I was working, was a pair of AC's back to back. DPU was not being used when I was working.
Never too old to have a happy childhood!
Greetings from Alberta
-an Articulate Malcontent
No ditch lights on the long hood end of modern six axle road power. Only engines used mainly for yard and locals might have ditch lights, including the rebuilt SD40-2 engines for yard/local service.
Jeff
OvermodWe have an amusing number of intermodal trains leaving Memphis on the ex-Southern NS that are long-hood-forward on the point to well east of Collierville. On the other hand there was evidence of careful 'handing' of units (first in cabs-out pairs and later elephant-style) on UP run-through power, and BNSF has gone through a couple of paradigm changes but maintained consistency between.
I don't think UP or BNSF puts ditch lights on the long hood end of road power. NS does. Allows them to run track speed long hood first.
It's been fun. But it isn't much fun anymore. Signing off for now.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any
BaltACDFalse assumption - what power is currently available that can move the tonnage to be moved in a On Time timeframe is the only consideration that is applied.
We have an amusing number of intermodal trains leaving Memphis on the ex-Southern NS that are long-hood-forward on the point to well east of Collierville. On the other hand there was evidence of careful 'handing' of units (first in cabs-out pairs and later elephant-style) on UP run-through power, and BNSF has gone through a couple of paradigm changes but maintained consistency between.
OvermodThe assumption I have always had is that whoever makes up the power for a given train carefully assesses what power to use, and where in the train or consist block it should go, and makes any more specific locomotive-type allocation as part of that (this includes which way some or all the cabs would be pointing, a more interesting issue than you might think). This would include "performance level" both as built and as perhaps degraded due to 'known but not yet critical' maintenance or repair issues.
False assumption - what power is currently available that can move the tonnage to be moved in a On Time timeframe is the only consideration that is applied.
Can't speak to other carriers. Since about 2010 all the power CSX was buying was being equipped to operate in DPU service - both as leaders and as mid or rear of train operators.
pennanealHow much does this have to do with the age and performance levels of these engines in use today?
Of course it presupposes that all the engines that need to control 'power blocks' in a train are physically equipped with DPU equipment.
Ideally you'd want AC rather than DC equipment in the distributed consists, as it simplifies some of the potential undetected-slip events that could happen with remote locomotives. Likewise, within a particular MUed distributed installation you might want to spec locomotives with similar loading characteristics so the application of power is a bit more predictable for train handling.
In theory you could install Locotrol III in much older locomotives, or MU antiques that use the same MU cable conventions into DPU consists. What is happening recently is that a number of Class Is are consolidating operating power into just a few classes of the most reliable (or fuel-efficient, or whatever floats their perceived PSR/shareholder boat) locomotives, presumably most or all of which will be set up with the DPU radio system if they are expected to lead.
The assumption I have always had is that whoever makes up the power for a given train carefully assesses what power to use, and where in the train or consist block it should go, and makes any more specific locomotive-type allocation as part of that (this includes which way some or all the cabs would be pointing, a more interesting issue than you might think). This would include "performance level" both as built and as perhaps degraded due to 'known but not yet critical' maintenance or repair issues.
Thanks, one more question. How much does this have to do with the age and performance levels of these engines in use today?
Thanks, Jeff.
1x1 = one engine in the lead, one engine at the very rear.
1x1x0 = one engine in the lead, one engine mid-train and no engine at the very rear.
That's the common understanding. Someone may also mean one engine consist instead of a single engine. When we have doubled up coal trains, some end up being a 2x3x1 configuration. Two engines in front, three engines mid-train and one engine at the very rear.
blue streak 1 What is interesting around here is CSX operating practices. Most DPU trains here are operated with a 1x1x0 operation with a few a 1x1 operation. At my location is a sag with northbound being the ruling grade. The middle or rear DPU is almost always in run 8 and the lead loco at whatever the train tonage requires for MAS. If train apparently very light front at idle and back whatever needed. If train slowing for stop mid train DPU full dynamic braking and slow application of brakes for final stopping. Notice a lot less rail squeel
What is interesting around here is CSX operating practices. Most DPU trains here are operated with a 1x1x0 operation with a few a 1x1 operation. At my location is a sag with northbound being the ruling grade. The middle or rear DPU is almost always in run 8 and the lead loco at whatever the train tonage requires for MAS. If train apparently very light front at idle and back whatever needed.
If train slowing for stop mid train DPU full dynamic braking and slow application of brakes for final stopping.
Notice a lot less rail squeel
Could you please explain 1x1 vs. 1x1x0. Thanks.
A passenger train might weigh 800 to 1,500 tons. A heavy freight train could weigh as much as 16,000 tons or more.
pennaneal wonder if you could expand your answer. I've also been wondering about engine placements being so varied. I don't get to see a lot of long trains but all videos including more recent with more powerful engines still use multiple engines in all configurations. is it all weight distribution? How much less horsepower to pull passenger trains? Thanks still learning.
wonder if you could expand your answer. I've also been wondering about engine placements being so varied. I don't get to see a lot of long trains but all videos including more recent with more powerful engines still use multiple engines in all configurations. is it all weight distribution? How much less horsepower to pull passenger trains? Thanks still learning.
timz UP used to have a rule that the DPU couldn't be more than 8500 ft from the head end. Maybe still does?
UP used to have a rule that the DPU couldn't be more than 8500 ft from the head end. Maybe still does?
Yes. And No. Depends on the type of train. Some are allowed 10,000 ft.
NKP guy Lately as I observe CSX trains on the old B&O near Akron I have seen trains with one locomotive on the head end and then another mid-train. Other trains have one locomotive at each end of the train. Why? Is there an advantage to doing it one way or the other? And why is simply putting all the power on the head end not done?
Why? Is there an advantage to doing it one way or the other? And why is simply putting all the power on the head end not done?
One of the theories being applied with distributed power is that it reduces the in train buff and draft forces as well as giving the engineer a greater ability to to control the slack adjustment that happens within the train.
Akron is the ruling grade between New Castle and Willard - a little over 1% in each direction from Akron Jct which is the bottom of the grade. At one time there was a permanent 10 MPH speed restriction at Akron Jct, thus trains could not 'make a run' for the grade.
Lately as I observe CSX trains on the old B&O near Akron I have seen trains with one locomotive on the head end and then another mid-train. Other trains have one locomotive at each end of the train.
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