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ECP braking -Better Call Saul

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Posted by charlie hebdo on Friday, March 3, 2023 5:43 AM

oltmannd

If you take PTC, ECP and DPU together you can have these things:

1. lighter freight cars with lower buff force requirement

2. eliminate time pumping air

3. automated brake testing

4. faster restricting speed

5. greatly reduced PU/SO times (see #2, #3)

6. reduced derailment risk - onboard health monitoring.

 

Which can mean longer crew districts, fewer locomotives in the fleet, fewer freight cars in the fleet, higher value of product.

Toss in route profile smoothing and electrification of heavy mainlines and you can really get things to move.

The whole is greater than the sum of the parts.  RRs are currently having a nice "going out of business sale".  PSR is really just a way to squeeze the last drops from declining carload franchise. Are there any leaders out there with any vision for this industry?

 

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.  

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Posted by tree68 on Friday, March 3, 2023 6:29 AM

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.

"I" don't want my return five or ten years from now.  "I" want it next month.

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Posted by Euclid on Friday, March 3, 2023 6:52 AM

tree68

 

 
Euclid
Say you have a 200-car train with ECP.  The 200 car valves open simultaneously (for all practical purpose).  Then it takes just a split second for all 200 car brakes to fully set simultaneously with maximum force.

 

It doesn't take long for the brakes to apply, but it's not instantaneous.  Air is still a fluid, flowing through pipes and hoses.  And there is the mechanical portion of the system.  

Even if it were instantaneous, there's Newton.

 

Well we are talking about performance of ECP brakes compared to conventional Westinghouse brakes (PCP brakes).  We can’t do anything about the Newton based reasons why the train will not instantly stop on a dime once a full brake application has been completed. So why even introduce that red herring into the conversation? It is just a given that we have to live with.  It does not take anything away from brake performance.  It does not mean that there is no point in trying to improve brake performance.  If the fact that freight trains can’t stop on a dime were a showstopper, we would not have freight trains. 
 
As to brake performance alone, whoever said any brake application was instantaneous?  And why does it matter that it is not instantaneous?  Does it need to be instantaneous in order to be sufficiently fast? 
 
I said that with ECP, the brake application happens to every car simultaneously.  I did not say “instantaneously” which would mean taking no time at all.  Simultaneously means the set does take some time, but every car sets within that same timeframe; because the signal to set moves at the speed of light. 
 
As I said, I am estimating a timeframe of 1/2-second for each car brake to apply in an emergency application. That is the time needed to open the valve and let higher pressure air in the emergency reservoir flow into the lower pressure, or non-pressurized brake cylinder until the pressure of the reservoir and brake cylinder equalize, thus producing maximum set force. 
 
And because every brake in the train applies simultaneously (which is entirely achievable), the entire train will apply all brakes in 1/2-second.  And you are saying that 1/2-second is not acceptable because what is needed is zero time.  With ECP, this is all the cars in 1/2-second; not 1/2-second for each car. 
 
Just 1/2-second and the entire train goes from fully released to fully set in emergency. 
 
I just don’t see your point of making this 1/2-second a deal breaker issue that proves ECP brakes are not viable. 
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Posted by SD60MAC9500 on Friday, March 3, 2023 10:14 AM
 

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

 

 

 
 
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Posted by tree68 on Friday, March 3, 2023 10:46 AM

Euclid
And because every brake in the train applies simultaneously (which is entirely achievable), the entire train will apply all brakes in 1/2-second.  And you are saying that 1/2-second is not acceptable because what is needed is zero time.  With ECP, this is all the cars in 1/2-second; not 1/2-second for each car. 

I did not say that 1/2 second was too slow.  And others have pointed out that it would take around 10 seconds to cover a 100 car train.  That's 1/10 second per car.

Change "applies" to "begins to apply" and "will apply all" to "will begin to apply all."

I point that out because I sense a feeling that ECP will be the panacea that will solve all our problems.  And I mention Newton because no matter how fast the brakes apply, it will still take substantial time to stop a train in an emergency situation.  So it stops in 3/4 mile instead of a mile?  So what if only 25 cars piled up at East Palestine - if the cars that did pile up included the hazmat, the end effect would not have changed. 

Once (if) the US railroads decide to try a full-scale application of ECP, they may decide it's worth the expense.  It's already been pointed out that the railroads prefer dynamics to air whenever possible, so I would opine that savings in wheels and brake shoes is not the factor it could be.  

In the meantime, as I mentioned earlier, those faster trains just get held out from the congested yards just that much sooner.  

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Posted by charlie hebdo on Friday, March 3, 2023 11:02 AM

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

 

 

 
 

Please include yourself in the list of those who have the vision to understand the long-term benefits of applying modern technology to legacy transportation. You and Don Oltmann.

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Posted by oltmannd on Friday, March 3, 2023 11:30 AM

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.

 

 

The joy of being retired!  (actually the last few years working I was rather a pain in the neck...)

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Posted by Overmod on Saturday, March 4, 2023 3:44 PM

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...

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Posted by Overmod on Saturday, March 4, 2023 3:50 PM

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...

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Posted by dpeltier on Saturday, March 4, 2023 10:29 PM

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

 

 

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Posted by SD60MAC9500 on Sunday, March 5, 2023 12:18 PM
 

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

 

 

 

"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. 

 
 
 
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Posted by oltmannd on Monday, March 6, 2023 8:07 AM

That the Booz Allen report is already 13 years old says a lot!

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Posted by Erik_Mag on Monday, March 6, 2023 11:35 PM

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.

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Posted by jeffhergert on Tuesday, March 7, 2023 12:34 AM

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.

 

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.  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.

Jeff

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Posted by Euclid on Tuesday, March 7, 2023 7:44 AM
There have been many reports over several years about elelctrical connector problems found in testing ECP brakes.  This is reported with the implication that the connector problem is a true showstopper that dooms the dream of ECP brakes in the U.S.  What is the precise, detailed description of the problem with connectors that have been developed and tested for U.S. application in ECP brake systems?
 
How does Rio Tinto address the connector problem with ECP brakes, which has been widely deemed unsolvable in American practice?  They run unit trains.  Are those trains hardwired for continuous connectivity without separable connectors?  If so, how is the cable mounted on the cars, and particularly, how is it handled between cars which are bouncing and rocking in relation to each other? 
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Posted by tree68 on Tuesday, March 7, 2023 9:46 AM

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.

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Posted by OldEngineman on Tuesday, March 7, 2023 11:12 AM

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?"

None. And... none.

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Posted by BaltACD on Tuesday, March 7, 2023 12:29 PM

OldEngineman
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?"

None. And... none.

Even with the best available braking - trains operating at track speed CAN NOT be stopped within the range of vision.

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Posted by Euclid on Tuesday, March 7, 2023 12:29 PM
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.

 
You may be right, but I am asking for some factual references.  First would be a reference to the actual technical issues with ECP connectors.  Yes electrical connectors can be troublesome with corrosion issues.  But I would expect that any such problem would be corrected by a better connector design that is capable of doing the job.  But in this case, the unclarified “connector problem” seems to killed the entire ECP concept.  It makes me wonder if that wasn’t the point. The adequate connector could be waterproof and stress proof for withstanding manual coupling and decoupling.
 
If there really is a problem with connectors in this country, I highly doubt that reduced rainfall in Australia is the only reason that allows the same connectors to be used in Australia. 
 
I suspect that the origianal connectors were just underdesigned so, while capable of handling the current, they were not robust enough in their contact pressue, pullout damage resistance, and moisture resistance.  I think the truly adequate connector would appear to be overkill because of its true need for robustness.  
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Posted by tree68 on Tuesday, March 7, 2023 1:17 PM

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

 

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Posted by Euclid on Tuesday, March 7, 2023 4:26 PM

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

Thanks for posting that catalog.  It looks like they test extensively for moisture issues.  I think there may have been problems with the ECP connectors in the earlier testing, which was on the N&W, as I recall.  But I suspect all the problems were solved by just upgrading the design to meet all of the needs for survival. 
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Posted by Erik_Mag on Tuesday, March 7, 2023 11:20 PM

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?

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Posted by BaltACD on Tuesday, March 7, 2023 11:29 PM

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?

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.

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Posted by tree68 on Wednesday, March 8, 2023 1:27 PM

Erik_Mag
One 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.  

 

 

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Posted by Erik_Mag on Wednesday, March 8, 2023 11:09 PM

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.

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Posted by tree68 on Wednesday, March 8, 2023 11:38 PM

Erik_Mag
With 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...

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Posted by Overmod on Thursday, March 9, 2023 4:33 AM

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...

  • Member since
    September 2002
  • From: Sterling Heights, Michigan
  • 1,691 posts
Posted by SD60MAC9500 on Thursday, March 9, 2023 2:52 PM
 

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...

 

 

Hey Mod I thought the ECP powerlink ran at 230VDC?

 
Rahhhhhhhhh!!!!
  • Member since
    February 2018
  • 299 posts
Posted by adkrr64 on Thursday, March 9, 2023 3:19 PM

What voltages are involved in the locomotive MU cables? Those get plugged/ unplugged all the time without any special precautions to power them down.

  • Member since
    May 2003
  • From: US
  • 25,292 posts
Posted by BaltACD on Thursday, March 9, 2023 3:44 PM

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 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.

Never too old to have a happy childhood!

              

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