When an engine is acting up for no obvious reason, pull the MU cable and see if that helps. Many engines now have a dummy receptacle for both ends of the MU cable. Sometimes leaving one end plugged into the live receptacle, even with the other end in the dummy slot can cause strange things to happen.
Jeff
oltmannd tree68 adkrr64 What voltages are involved in the locomotive MU cables? Those get plugged/ unplugged all the time without any special precautions to power them down. I just asked someone who would know, but he's not here on the forum. I'd guess nothing over 72VDC. Edit: MU cables carry 74 VDC control voltages, at least in the old stuff we run. I'd have to believe we could still MU our old ALCOs with anything modern. 74VDC. And they don't carry for more than a dozen or so connections, reliably. RRs have rules about how many locos can be MUed. Also, you have to do a continuity check every time you build a consist. MU connectors and cable do fail and get burned contacts, but they are pretty reliable - they also "fail safe".
tree68 adkrr64 What voltages are involved in the locomotive MU cables? Those get plugged/ unplugged all the time without any special precautions to power them down. I just asked someone who would know, but he's not here on the forum. I'd guess nothing over 72VDC. Edit: MU cables carry 74 VDC control voltages, at least in the old stuff we run. I'd have to believe we could still MU our old ALCOs with anything modern.
adkrr64 What voltages are involved in the locomotive MU cables? Those get plugged/ unplugged all the time without any special precautions to power them down.
What voltages are involved in the locomotive MU cables? Those get plugged/ unplugged all the time without any special precautions to power them down.
I just asked someone who would know, but he's not here on the forum. I'd guess nothing over 72VDC.
Edit: MU cables carry 74 VDC control voltages, at least in the old stuff we run. I'd have to believe we could still MU our old ALCOs with anything modern.
74VDC. And they don't carry for more than a dozen or so connections, reliably. RRs have rules about how many locos can be MUed. Also, you have to do a continuity check every time you build a consist.
MU connectors and cable do fail and get burned contacts, but they are pretty reliable - they also "fail safe".
All depends on what the definition of SAFE is.
https://www.ntsb.gov/investigations/AccidentReports/Reports/RAR0202.pdf
Because of MU failure engineer only had Dynamic Braking on the lead unit, not all three units like he thought.
Never too old to have a happy childhood!
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
According to this, 74 volts DC. Something else to consider, I believe the MU cabling is all signal and control, and not providing significant power to anything so wouldn't provide much current, whereas the ECP brake cable would have to provide enough current to power 200+ brake controls.
adkrr64What voltages are involved in the locomotive MU cables? Those get plugged/ unplugged all the time without any special precautions to power them down.
I don't specifically know, however, I doubt that they are anywhere near 220v. Also MU cable connection are manually broken when necessary to swtich engines out of the engine consist.
Overmod ECP is nominally 220VAC at 60Hz (with powerline data modulation), and 'supposedly' the fancy standard connector (I've forgotten the standard # and am not going to look it up on a phone) is safe to connect and disconnect in poor weather. Personally I would not buy it for a quarter once a little time and grime and typical railroad maintenance have become involved, even with 'railroad-issue' safe PPE gloves...
ECP is nominally 220VAC at 60Hz (with powerline data modulation), and 'supposedly' the fancy standard connector (I've forgotten the standard # and am not going to look it up on a phone) is safe to connect and disconnect in poor weather. Personally I would not buy it for a quarter once a little time and grime and typical railroad maintenance have become involved, even with 'railroad-issue' safe PPE gloves...
Hey Mod I thought the ECP powerlink ran at 230VDC?
Erik_MagWith respect to working in wet weather, one option is to cut the ECP power when a cable needs to be changed out.
We don't even think of touching the HEP unless it's confirmed to be down.
Yes, HEP is 480 VAC (or 408), and the ECP is reported as 220v (maybe even DC?). But you can weld with lesser voltages...
With respect to working in wet weather, one option is to cut the ECP power when a cable needs to be changed out. OTOH, it would be possible to design the connector housing to remain grounded until after the ECP contacts have fully disconnected.
I would be very wary of dealing with a frayed cable with an exposed conductor even in dry weather.
Erik_MagOne thought is to have replaceable cables on the car ends - think the electrical equivalent of air brake hoses.
The document I cited earlier shows exactly that.
There is a twist-lock connector on the car end. The connector that connects to the next car has specs for being able to be pulled apart. This actually makes the cable very similar to the brake hoses. They would have to be "made," but will pull apart when the car is uncoupled.
It does mean that in addition to a brake hose or two, each crew will have to have a stock of the cables available.
Erik_Mag jeffhergert I've read in the past about using the cable for DP control. Yes, that would be better. However, will the connections, etc. be properly maintained? I doubt it. Based on my experience with connections, your skepticism is warranted. The relatively high voltages (IIRC ~ 220VDC) should cut through some of the corrosion, but... One thought is to have replaceable cables on the car ends - think the electrical equivalent of air brake hoses. The idea is that the car to cable connection would be undone rarely and thus last longer than the connections between the cables coming from the cars. This would require some quick way to ascertain whether a connection is good - perhaps a light on the cable itself?
jeffhergert I've read in the past about using the cable for DP control. Yes, that would be better. However, will the connections, etc. be properly maintained? I doubt it.
I've read in the past about using the cable for DP control. Yes, that would be better.
However, will the connections, etc. be properly maintained? I doubt it.
Based on my experience with connections, your skepticism is warranted. The relatively high voltages (IIRC ~ 220VDC) should cut through some of the corrosion, but...
One thought is to have replaceable cables on the car ends - think the electrical equivalent of air brake hoses. The idea is that the car to cable connection would be undone rarely and thus last longer than the connections between the cables coming from the cars. This would require some quick way to ascertain whether a connection is good - perhaps a light on the cable itself?
From the perspective of a employee on the ground in dealing various defects that routinely happen in getting a train over the road - knowing the there is a live 220v line that is now active on the train would be rather offsetting when dealing with the trains issues in wet or snowy weather.
tree68 Here's a standard for the connectors. Not freight, but they'd need to be interchangeable. https://www.apta.com/wp-content/uploads/APTA-PR-M-S-022-19.pdf
Here's a standard for the connectors. Not freight, but they'd need to be interchangeable.
https://www.apta.com/wp-content/uploads/APTA-PR-M-S-022-19.pdf
tree68 Euclid How does Rio Tinto address the connector problem with ECP brakes, which has been widely deemed unsolvable in American practice? Weather. I think you'll find that Rio Tinto is running in a mostly dry environment. I could be wrong. The northern US (and Canada) deals with winter weather (snow, etc), and except for the southwest, the southern US is is pretty wet. Moisture breeds corrosion. And the unit trains factor is huge. The cars are almost always connected, so there's no need to connect and disconnect the cables frequently, regardless of how that connection is made.
Euclid How does Rio Tinto address the connector problem with ECP brakes, which has been widely deemed unsolvable in American practice?
Weather.
I think you'll find that Rio Tinto is running in a mostly dry environment. I could be wrong.
The northern US (and Canada) deals with winter weather (snow, etc), and except for the southwest, the southern US is is pretty wet.
Moisture breeds corrosion.
And the unit trains factor is huge. The cars are almost always connected, so there's no need to connect and disconnect the cables frequently, regardless of how that connection is made.
OldEnginemanSD60Mac asks: "The stopping distance is a bonus of ECP yet imagine with improved braking how many grade crossing incidents could potentially be avoided? Or even low/medium speed rail collisions?" None. And... none.
None. And... none.
Even with the best available braking - trains operating at track speed CAN NOT be stopped within the range of vision.
SD60Mac asks: "The stopping distance is a bonus of ECP yet imagine with improved braking how many grade crossing incidents could potentially be avoided? Or even low/medium speed rail collisions?"
EuclidHow does Rio Tinto address the connector problem with ECP brakes, which has been widely deemed unsolvable in American practice?
Erik_Mag Something that I don't recall being discussed in detail is using the ECP trainline for DPU control. Theoretically, the advantage over radio control is that the wired connection should not experience drop-outs. That would imply that the DPU timeouts could be a very few seconds before the units go into idle after losing contact.
Something that I don't recall being discussed in detail is using the ECP trainline for DPU control. Theoretically, the advantage over radio control is that the wired connection should not experience drop-outs. That would imply that the DPU timeouts could be a very few seconds before the units go into idle after losing contact.
However, will the connections, etc. be properly maintained? I doubt it. That's my biggest concern with PTC. It works fairly well now, while it's new. Just like the DP equipment. What about a few years from now? Much of the DP problems are from the seemingly isignificant components, namely the wires and connections.
I fear that those similar components for other systems will be maintained in the same fashion.
That the Booz Allen report is already 13 years old says a lot!
dpeltier SD60MAC9500 The main point missing from Don's argument is that ECP itself will reduce maintenance expense. Wheel life is extended and its associated running gear. Brake shoes can last longer with more even wear. Also track forces are greatly reduced with ECP. This has all been proven in testing of ECP on; ATSF, BN, Conrail, BNSF, CP, CSX, and UP. Read here for the conclusions on ECP testing: https://acrobat.adobe.com/link/review?uri=urn:aaid:scds:US:457b55c4-93e9-3803-aa07-77b079ed4cb2 https://acrobat.adobe.com/link/review?uri=urn:aaid:scds:US:c447b44c-cd17-35f8-86d8-9709e97bf6d8 A better summary of various ECP pilot programs and their results is in the appendix of the 2006 Booz Allen Hamilton report: https://railroads.dot.gov/elibrary/ecp-brake-system-freight-services And I will concede that the three results with concrete cost savings that were consistently observed were reduction in fuel use, reduction in wheel temperatures and related wheel changeouts, and reduction in brake shoe replacements. So it was probably an overstatement to say that existing ECP brakes offer NO significant benefits in dollars and cents. However... reading the Canadian Pacific report - the most recent and most detailed one I saw in my Googling adventures - also reveals some reason to doubt that the magnitude of the reported savings would hold up in the long run. Fuel use: Note that CP reported fuel savings of 4.6%, which is below the range reported for earlier studies, despite the fact that the CP test route is ideal for optimizing ECP benefits: empties moving uphill, loads moving down 2.5% grades interrupted by short 0-1% grades. The fuel savings (and reduced lateral track forces) are attributed almost entirely to the use of power braking in these short flatter stretches, which can be avoided with ECP brakes using graduated release. Other pilot implementations also attribute the fuel savings to the elimination of power braking. That makes sense; however, fuel management procedures have likely reduced the use of power braking in conventional-brake operations network-wide since most of the pilots were conducted. In fact, the 4.6% reduction in the case of the CP's ideal route, versus 5% or more on less ideal routes in earlier experiments, may be a sign that the diminishing returns due to overall better fuel management were already kicking in by 2008-2010. Then compare the CP route to, say, a unit grain train moving from North Dakota to Portland, OR. The CP trains runs up the 2.5% grade empty; if I interpolate correctly from the info in the paper, they had about 1 HP / ton. Clearly that's not going to provide enough DB for a 2.5% descending grade, so it has to use a lot of air - which then results in heavy power braking on the flat spots. The grain train, on the other hand, is going to have a similar HP / ton of around 0.9, but will only have descending grades greater than 1% (maxing out at 1.9%) for about 25 miles of it's ~1,400 mile journey. So a much larger percentage of the braking force will come from the DB's, making graduated release less important. So: yes, fuel savings, but probably a very small percent systemwide in 2023. Wheel temps / wheel defects: High high wheel temps lead to wheel defects. Generally, ECP results in more consistent wheel temps from csr to car, reducing the number of hot wheels and therefore the number of wheel defects. The effects may be mitigated in the near future by improved analytics. Wheel temps are easily monitored using wayside detectors, and the use of "big data" techniques to identify problems before they become condemnable defects is a hot topic these days. It's certainly possible that cars with sticky brakes, leaky cylinders, etc. may be detectable and fixable before they develop (or cause other cars to develop) heat-related wheel defects. In the case of the CP paper, I also question the appropriateness of comparing the brand-new cars ordered with ECP brakes to the general fleet of unknown age. Brake shoes: I think this mostly follows the same reasoning as wheel temps - less variation in braking force between cars, which could possibly be mitigated with conventional brakes by better detection and maintenance. Dan
SD60MAC9500 The main point missing from Don's argument is that ECP itself will reduce maintenance expense. Wheel life is extended and its associated running gear. Brake shoes can last longer with more even wear. Also track forces are greatly reduced with ECP. This has all been proven in testing of ECP on; ATSF, BN, Conrail, BNSF, CP, CSX, and UP. Read here for the conclusions on ECP testing: https://acrobat.adobe.com/link/review?uri=urn:aaid:scds:US:457b55c4-93e9-3803-aa07-77b079ed4cb2 https://acrobat.adobe.com/link/review?uri=urn:aaid:scds:US:c447b44c-cd17-35f8-86d8-9709e97bf6d8
The main point missing from Don's argument is that ECP itself will reduce maintenance expense. Wheel life is extended and its associated running gear. Brake shoes can last longer with more even wear. Also track forces are greatly reduced with ECP. This has all been proven in testing of ECP on; ATSF, BN, Conrail, BNSF, CP, CSX, and UP.
Read here for the conclusions on ECP testing:
https://acrobat.adobe.com/link/review?uri=urn:aaid:scds:US:457b55c4-93e9-3803-aa07-77b079ed4cb2
https://acrobat.adobe.com/link/review?uri=urn:aaid:scds:US:c447b44c-cd17-35f8-86d8-9709e97bf6d8
A better summary of various ECP pilot programs and their results is in the appendix of the 2006 Booz Allen Hamilton report:
https://railroads.dot.gov/elibrary/ecp-brake-system-freight-services
And I will concede that the three results with concrete cost savings that were consistently observed were reduction in fuel use, reduction in wheel temperatures and related wheel changeouts, and reduction in brake shoe replacements. So it was probably an overstatement to say that existing ECP brakes offer NO significant benefits in dollars and cents.
However... reading the Canadian Pacific report - the most recent and most detailed one I saw in my Googling adventures - also reveals some reason to doubt that the magnitude of the reported savings would hold up in the long run.
Fuel use:
Note that CP reported fuel savings of 4.6%, which is below the range reported for earlier studies, despite the fact that the CP test route is ideal for optimizing ECP benefits: empties moving uphill, loads moving down 2.5% grades interrupted by short 0-1% grades. The fuel savings (and reduced lateral track forces) are attributed almost entirely to the use of power braking in these short flatter stretches, which can be avoided with ECP brakes using graduated release. Other pilot implementations also attribute the fuel savings to the elimination of power braking. That makes sense; however, fuel management procedures have likely reduced the use of power braking in conventional-brake operations network-wide since most of the pilots were conducted. In fact, the 4.6% reduction in the case of the CP's ideal route, versus 5% or more on less ideal routes in earlier experiments, may be a sign that the diminishing returns due to overall better fuel management were already kicking in by 2008-2010.
Then compare the CP route to, say, a unit grain train moving from North Dakota to Portland, OR. The CP trains runs up the 2.5% grade empty; if I interpolate correctly from the info in the paper, they had about 1 HP / ton. Clearly that's not going to provide enough DB for a 2.5% descending grade, so it has to use a lot of air - which then results in heavy power braking on the flat spots. The grain train, on the other hand, is going to have a similar HP / ton of around 0.9, but will only have descending grades greater than 1% (maxing out at 1.9%) for about 25 miles of it's ~1,400 mile journey. So a much larger percentage of the braking force will come from the DB's, making graduated release less important.
So: yes, fuel savings, but probably a very small percent systemwide in 2023.
Wheel temps / wheel defects:
High high wheel temps lead to wheel defects. Generally, ECP results in more consistent wheel temps from csr to car, reducing the number of hot wheels and therefore the number of wheel defects.
The effects may be mitigated in the near future by improved analytics. Wheel temps are easily monitored using wayside detectors, and the use of "big data" techniques to identify problems before they become condemnable defects is a hot topic these days. It's certainly possible that cars with sticky brakes, leaky cylinders, etc. may be detectable and fixable before they develop (or cause other cars to develop) heat-related wheel defects.
In the case of the CP paper, I also question the appropriateness of comparing the brand-new cars ordered with ECP brakes to the general fleet of unknown age.
Brake shoes:
I think this mostly follows the same reasoning as wheel temps - less variation in braking force between cars, which could possibly be mitigated with conventional brakes by better detection and maintenance.
Dan
"In the case of the CP paper, I also question the appropriateness of comparing the brand-new cars ordered with ECP brakes to the general fleet of unknown age."
I can agree with that statement. Yet being a new order I imagine it was easier to order brand new than to retrofit ECP equipment on the existing fleet.
Perhaps diminishing returns yet those fuel savings can't be ignored. I'll also point out that various testing has been done under what's called Phase 1 ECP. Where it's overlayed onto the conventional system. The final phase(Phase-3)of ECP calls for complete replacement of all conventional controls in place of electronic control.
If we can test a trainset(s) with P3 ECP I think the test results may prove much more fruitful than the exisiting overlay.
I believe the industry needs to get the ball rolling on a move away from wayside equipment for bearing, dragging equipment, and wheel detection. This needs to eventually move onboard.
Thanks for including the Booz-Allen report.
I have said for decades that the advantages of ECP are significant, and have even proposed methods both for technical and financial implementation on North American railroads.
Just don't lie and claim the 3% improvement in emergency is a 'safety' mandate to be funded only by railroads...
Unless some of the vast stranded cost for the conversions isn't covered in some way, the changeover likely won't have much traction. And most unit trains that can be quickly converted don't have much crash, PIH, or BLEVE risk.
All the technology and even some of the manpower and training cadres exist for rapid change, but it's a big chunk of probably over 4T by now before you start getting interchange consists with solid blocks of converted cars...
tree68 charlie hebdo Judging by this thread, only Don has the vision for making rails an improving endeavor rather than a declining business with a siege or "going out of business" mentality. I have no doubt that there are those in the rail industry who share Don's vision. They know enough to keep their mouths shut, however.
charlie hebdo Judging by this thread, only Don has the vision for making rails an improving endeavor rather than a declining business with a siege or "going out of business" mentality.
I have no doubt that there are those in the rail industry who share Don's vision.
They know enough to keep their mouths shut, however.
The joy of being retired! (actually the last few years working I was rather a pain in the neck...)
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