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ECP braking -Better Call Saul

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ECP braking -Better Call Saul
Posted by oltmannd on Saturday, February 25, 2023 10:16 PM

They are both from the 90s. Only one is entertaining.

https://blerfblog.blogspot.com/2023/02/just-stop-it-train-brakes.html?m=0

 

 

 

 

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Posted by SD60MAC9500 on Sunday, February 26, 2023 9:59 AM
 

75% of the North American car fleet is private what incentive will you create for; GATX, Mitsui, CAI, VTG et al. to eat those cost?.

I also don't know why braking keeps coming up in a derailment that any form of braking clearly would not have prevented..

 
 
 
 
 
 
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Posted by dpeltier on Sunday, February 26, 2023 11:27 AM

oltmannd

They are both from the 90s. Only one is entertaining.

https://blerfblog.blogspot.com/2023/02/just-stop-it-train-brakes.html?m=0

This is an interesting essay, but I do think it misstates a few things.

First off, it misses the second-biggest reason why ECP brakes went nowhere after they were tested in the 2000's. The biggest reason, as everyone agrees, is the lack of a workable path towards full adoption. But the second biggest reason is this: economically, there were almost no advantages to the ECP system.

Stopping distances are reduced by half? So what? At best this can make a very marginal difference in track capacity at a few chokepoints. At worst, the faster service breaking is literally never used, because fuel conservation practices already result in a train reducing its speed long before it reaches the minimum stopping distance to the next red signal. (Actually, at worst: engineers start to rely more on air braking and less on dynamics, which increases brake wear. I heard a rumor that was actually an observed phenomenon on ECP test trains.)

Train dynamics are easier to manage? Maybe - the locomotive engineers will have to weigh in on this - but I doubt it? Slack will still be a thing. I don't think most broken knuckles / pulled drawbars / train-handling derailments have anything to do with brake response time.

Runaway prevention? ECP brakes, with their graduated release feature, might prevent some fraction of runaways. These events are so rare that you're talking about a fraction of a very small number; economically, it's not significant.

The only actual payback on the investment came from some FRA regulatory relief. I don't recall the details. I think FRA gave some incentives for ECP trains under a waiver, mostly by eliminating or reducing the requirements of the 1,000 / 1,500 mile inspection. It didn't really move the needle, and might have diminishing returns if you expanded it to non-unit trains.

And all of this leads to my second main complaint about the essay: the reason why the railroads lobbied against the ECP-for-oil-trains regulation was because the regulation was blatantly illegal. Unlike legislation, regulations are required to produce a positive cost / benefit ratio. The regulators, either out of ignorance or for political reasons, totally misunderstood the costs. But more to the point, they didn't understand the so-called benefits and didn't really seem to care. At the end of the day the Transportation Research Board (TRB - the part of the National Academies responsible for providing technical advice to the government on all transportation-related matters) concluded that the regulators simply hadn't demonstrated that ECP brakes would prevent any hazmat releases at all.

So where does this leave us? Well... compare where we are to where PTC was a couple decades ago. Some prototype demonstrations have shown that it is physically possible to implement. The massive cost of PTC was never justified by the safety benefits, and the cost / benefit for ECP is probably tens or hundreds of times worse than it was for PTC.

Where PTC went next was: how can we increase the benefits to include more than just reduced accidents? NAJPTC was probably the best stab at this, and it unfortunately was a miserable stinking failure that kind of shut down that approach for a while. There was also a fair amount of talk pre-Chatsworth discussion about the fact that the only conceivable way to make the economics work was to reduce crew consists. Then Congress adopted the PTC mandate, and the discussion immediately shifted from, "How can PTC really make economic sense?" to "How in the hell can we pull something together that will meet the requirements of the law on the mandated timeline?" Now that it is all in place, the original questions are coming back - how can we use PTC infrastructure to improve operations and reduce costs.

With ECP brakes, I haven't seen much effort to define a new ECP protocol that would add operational benefits. If Congress were to require ECP at this point, it would be a disaster - you only would get one chance to do it right, and the only available technology is not "doing it right".

It would probably be good if FRA and AAR could get together and start working on a next-gen ECP system that has, or is flexible enough to allow for, some actual benefits to the railroad. If nothing else, this would be some insurance against stupid laws in the future.

(My personal moonshot vision: a system that allows autonomous braking for a disconnected car in a yard - program the car with a speed vs distance profile, kick it or roll it down a hump, and let it glide to a smooth joint with no retarder needed. Also, sensors that can measure slack and in-train forces, and a controller at the head and that can apply brakes automatically on individual cars or sets of cars to keep those forces within acceptable range. No idea whether these could be made to work, but maybe a new ECP protocol could at least allow for the possibility.)

Dan

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Posted by BaltACD on Sunday, February 26, 2023 12:45 PM

When I was still working CSX was instructing Engineers that Dynamic Braking was their primary form of braking and the use of air brakes was a secondary braking tool.  I can only believe in the past 7 years that the use of air brakes has been incresingly discouraged.  ECP or not, if you aren't using air in the first place there is absolutely no advantage to ECP.

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Posted by mvlandsw on Sunday, February 26, 2023 2:50 PM

BaltACD

When I was still working CSX was instructing Engineers that Dynamic Braking was their primary form of braking and the use of air brakes was a secondary braking tool.  I can only believe in the past 7 years that the use of air brakes has been incresingly discouraged.  ECP or not, if you aren't using air in the first place there is absolutely no advantage to ECP.

 

Except in an emergency application where all the brakes would apply at once instead of serially, eliminating the problems caused by severe slack action. Still probably not economically justifiable.

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Posted by oltmannd on Sunday, February 26, 2023 3:22 PM

dpeltier
First off, it misses the second-biggest reason why ECP brakes went nowhere after they were tested in the 2000's. The biggest reason, as everyone agrees, is the lack of a workable path towards full adoption.

Literally in the post "The biggest one is no one has been able to provide leadership that leads down the implementation path. Managing through the change from standard to ECP braking is fraught with problems."

-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/

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Posted by oltmannd on Sunday, February 26, 2023 3:24 PM

dpeltier
But the second biggest reason is this: economically, there were almost no advantages to the ECP system.

Okay.  That's what they said about PTC...and have now changed their tune.

A workable ECP system gets you a whole host of other things with that data trainline.  That's where the money is...  It's a building block for faster average velocity, longer crew district railroading...  Which is needed if the RRs have any real future.

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Posted by 7j43k on Sunday, February 26, 2023 5:32 PM

oltmannd

 

 
dpeltier
But the second biggest reason is this: economically, there were almost no advantages to the ECP system.

 

Okay.  That's what they said about PTC...and have now changed their tune.

A workable ECP system gets you a whole host of other things with that data trainline.  That's where the money is...  It's a building block for faster average velocity, longer crew district railroading...  Which is needed if the RRs have any real future.

 

 

Ah.  I see.  The money is in the other things.  

And those other things are....?

 

Ed

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Posted by dpeltier on Sunday, February 26, 2023 5:42 PM

oltmannd
dpeltier
But the second biggest reason is this: economically, there were almost no advantages to the ECP system.

 

Okay.  That's what they said about PTC...and have now changed their tune.

A workable ECP system gets you a whole host of other things with that data trainline.  That's where the money is...  It's a building block for faster average velocity, longer crew district railroading...  Which is needed if the RRs have any real future.

I was talking about the AAR standard for ECP brakes that was developed in the late 1990's and implemented on some test trains in the 2000's. That standard did NOT support a "data bus" linking cars together, and from what I could glean, did not really have any extensibility built in. It is also the ONLY standard for ECP brakes that has been developed for North American freight trains at this time, and if there is a legal requirement to implement ECP brakes within a 5- or 10-year horizon, it will almost certainly be the basis of that effort, for lack of any alternatives.

I agree that the situation is somewhat analogous to PTC, but:

1.) PTC is a long way from paying for itself too. Yeah, it's nice to deliver track bulletins electronically. It's not worth billions and billions of dollars. If PTC turns out to be the thing that enabled a reduction in crew size, then it might - MIGHT - earn back it's cost some day.

2,) The benefits that we're starting to see from PTC were foreseen way before PTC was implemented. They just didn't justify the cost. By contrast, the benefits from ECP brakes are much less clear and much less compelling, while the cost of implementation is far larger.

I agree that you could do a lot with a data link between freight cars, but most of them aren't worth that much in the big picture, and some of them can be accomplished with other technologies. Furthermore, there isn't actually any reason why you need ECP brakes to implement a data link along the train. It would be much easier to design a non-vital data link to run all the nifty on-board sensors and whatnot than to design a safety-critical, failsafe braking system.

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Posted by Overmod on Sunday, February 26, 2023 6:36 PM

Mr. Peltier, what Mr. Oltmann is referring to is what's called 'powerline modulation' over the 220V electrical line required for current ECP.  "Internet of Things" connections depended very heavily on some form of 120V 'home' powerline modulation in the years before pervasive WiFi and 4G/5G/LTE; before systems like Zigbee there was utility in implementing Salutation Protocol over powerline modulation so fhtat office equipment would 'configure itself' and interwork merely by being plugged in.  Great strides in the technology have been made since the early Nineties!

In my opinion, while the attempt to mandate ECP for key trains was a laudable thing, and reminiscent of the original Esch Act strategy for rolling implementation of ATC for block signaling... the only case the FRA could make was one based on safety.  And 3% improvement for over $3T was not enough 'safety' to make the trick work; we might as well have tried implementing Euclid's armored General Products #4 hulls.  When actual scientific assessment of the ECP mandate was conducted in 2017, the idea was thrown out... not because of some supposed Trumpster meddling, but simply because the gains didn't justify either the expense or the risks during implementation.

What might be interesting is a 'creeping featurization' implementation of the power/data trainline combined with wireless/RF data fusion for 'breaks in the trainline' or contactless modem data transfer to 'passive' wiring.  If QR and PM hadn't become mainstream kludges... that might get you a long way toward ECP-like actuation and release from one-pipe brakes with those modules every 10 to 20 cars in a consist.

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Posted by jeffhergert on Sunday, February 26, 2023 7:01 PM

mvlandsw

 

 
BaltACD

When I was still working CSX was instructing Engineers that Dynamic Braking was their primary form of braking and the use of air brakes was a secondary braking tool.  I can only believe in the past 7 years that the use of air brakes has been incresingly discouraged.  ECP or not, if you aren't using air in the first place there is absolutely no advantage to ECP.

 

 

 

Except in an emergency application where all the brakes would apply at once instead of serially, eliminating the problems caused by severe slack action. Still probably not economically justifiable.

 

With the difference in braking force between cars, ECP in emergency might not totally eliminate some severe slack action incidents.

For use dynamics first and then dynamics with air is preferred.  However, they've relaxed what their definition of power or stretch braking is that allows using air when in higher throttle notches than before.  There are still some in management that realize there are times when you need to use air when in power.

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Posted by oltmannd on Sunday, February 26, 2023 8:38 PM

7j43k

 

 
oltmannd

 

 
dpeltier
But the second biggest reason is this: economically, there were almost no advantages to the ECP system.

 

Okay.  That's what they said about PTC...and have now changed their tune.

A workable ECP system gets you a whole host of other things with that data trainline.  That's where the money is...  It's a building block for faster average velocity, longer crew district railroading...  Which is needed if the RRs have any real future.

 

 

 

 

Ah.  I see.  The money is in the other things.  

And those other things are....?

 

Ed

 

Did you read the blog post?  They're in there.

-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/

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Posted by oltmannd on Sunday, February 26, 2023 8:41 PM

jeffhergert
With the difference in braking force between cars, ECP in emergency might not totally eliminate some severe slack action incidents.

I can see that if you don't have empty/load braking.

jeffhergert
For use dynamics first and then dynamics with air is preferred.  However, they've relaxed what their definition of power or stretch braking is that allows using air when in higher throttle notches than before.  There are still some in management that realize there are times when you need to use air when in power.

This is a good thing!  The goal is get the stuff over the road in one piece.  RRs are not "fuel savings" companies.  Service first!

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Posted by oltmannd on Sunday, February 26, 2023 8:43 PM

Overmod
Mr. Peltier, what Mr. Oltmann is referring to is what's called 'powerline modulation' over the 220V electrical line required for current ECP. 

Yep.  It's why the "state of the art" is obsolete.  Also, a 100+, 60' "extension cords" running 220V plugged in end-to-end is a really terrible idea.

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Posted by oltmannd on Sunday, February 26, 2023 8:46 PM

Overmod
In my opinion, while the attempt to mandate ECP for key trains was a laudable thing...

As the industry didn't move an inch forward on this at that time, anything to light a fire under them would have been a good thing.  Pay back?  Yeah, I doubt it, but that's not the point.

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Posted by oltmannd on Sunday, February 26, 2023 8:53 PM

Implementation strategy?

Unit trains first.  Easiest.  Least valuable, but best place to hone the product.

Then intermodal.  Relatively few cars - by A LOT.  They tend to stay in chunks, so segregating fleet not as hard.

Loose cars...Very hard, but by the time we get the first two done, RRs will be primarily intermodal with botique car load business.  Some combo of pass thru data connections on older cars, new cars with dual provision and retrofitting and block segregation and mixed mode trains using DPUs or "MOT"s might be a way forward.  Requires quite a bit of operational modeling...

This is a long term project!  A couple decades, at least, if they start now.

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Posted by SD70Dude on Sunday, February 26, 2023 11:25 PM

CN and CP just missed a big opportunity as they and the grain companies purchased thousands of new grain hoppers over the past decade or so to replace the old cylindrical 4-bay 'Trudeau' fleet. 

Greetings from Alberta

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Posted by Erik_Mag on Monday, February 27, 2023 1:11 AM

Overmod

Mr. Peltier, what Mr. Oltmann is referring to is what's called 'powerline modulation' over the 220V electrical line required for current ECP.  "Internet of Things" connections depended very heavily on some form of 120V 'home' powerline modulation in the years before pervasive WiFi and 4G/5G/LTE; before systems like Zigbee there was utility in implementing Salutation Protocol over powerline modulation so fhtat office equipment would 'configure itself' and interwork merely by being plugged in.  Great strides in the technology have been made since the early Nineties!

Power line modulation goes back a l-o-n-g way. One example appropriate for this forum (well maybe the MR forum) was GE's Astrac that used a high frequency burst to trigger the firing of an SCR to vary the speed of the locomotive.

There have been a lot of advances in low cost signal processing since the 1990's, which could make for a more robust modulation/detection scheme than was possible back then. With ECP, the required data rate isn't all that great, which means that it can use audio or low radio frequencies for the carrier(s) which will help in getting the signal through several thousand feet of cable and 100+ connectors. I think it should be mandatory that the EOT provide proof of connectivity.

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Posted by oltmannd on Monday, February 27, 2023 8:56 AM

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?

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Posted by oltmannd on Monday, February 27, 2023 8:57 AM

...and by "really move"  I don't mean higher track speeds.  I mean less time stopped and going slow.

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Posted by oltmannd on Monday, February 27, 2023 8:59 AM

Erik_Mag
With ECP, the required data rate isn't all that great,

Which should make it easier to pile on lots of other information, like onboard defect detection...

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Posted by tree68 on Monday, February 27, 2023 9:20 AM

oltmannd

...and by "really move"  I don't mean higher track speeds.  I mean less time stopped and going slow.

So the train gets to its hold-out parking spot a little sooner...

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Posted by daveklepper on Monday, February 27, 2023 9:26 AM

One feature that, to my knowledge, has not been included in Electric\electronic braking systems tested so far, but must be included is:

A rapid sharp drop in train-line air presure, that would execute an emergency stop by propgation of the pressure drop alone, must also activate the electrical\electronic emergency braking.

This wiould have mitigated both the Megantic and the East Palestine damages.  Brakes should apply unbiformly under all conhditiond, including vedmergencies.

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Posted by Overmod on Monday, February 27, 2023 9:31 AM

daveklepper
A rapid sharp drop in train-line air pressure, that would execute an emergency stop by propagation of the pressure drop alone, must also activate the electrical\electronic emergency braking.

It does already, on both systems.  The immediate actuation of all emergency valves in the train simultaneously, rather than 'at the speed of sound in compressed air', is what produces the roughly 3% reduction in achieved stopping distance.

I do not know whether providing an ECP emergency trip at each emergency valve, to be triggered when any valve in the train physically goes to emergency, or if the trainline pressure drops 'uncommanded' below a critical level, is part of current systems.  A problem with it is that any sort of UDE instantly slams the train into full emergency without warning, but all the issues with brakes applying differently or slack condition still apply regardless of how quickly the valve modulates.

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Posted by SD60MAC9500 on Monday, February 27, 2023 11:59 AM
 

dpeltier

 

Stopping distances are reduced by half? So what? At best this can make a very marginal difference in track capacity at a few chokepoints. At worst, the faster service breaking is literally never used, because fuel conservation practices already result in a train reducing its speed long before it reaches the minimum stopping distance to the next red signal. (Actually, at worst: engineers start to rely more on air braking and less on dynamics, which increases brake wear. I heard a rumor that was actually an observed phenomenon on ECP test trains.)

 

 
This is correct Dan greater wear was reported in the initial testing of ECP. However that was only because of being unfamiliar with the advanced braking system. As Engineers gained more experience using ECP. Wear reduced considerably over conventional ABV equipment.
 
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? ECP has shown to reduce fuel usage, and improve wheel condition by allowing precise modulation of braking. This has led to lower wheel temps especially on descending grades where temperatures have been recorded at lower temps than trains using conventional ABV/DB.
 
The attributes Don list that are known about ECP are not immaterial and would provide saving to the industry, but we know the C1's don't like high upfront cost that will actually save them OPEX in the long term... Yet 75% of the fleet being private is the issue in this case. Not the C1's.
 
So how does the rail industry entice private fleets to start laying groundwork for adoption? Credit system? Lower rates for those fleets equipped? Should the C1's start a loan program where the private operators can spread their cost? ECP will help lower the rail industry's OPEX.
 
 
 
 
 
Rahhhhhhhhh!!!!
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Posted by tree68 on Monday, February 27, 2023 12:15 PM

Overmod
A problem with it is that any sort of UDE instantly slams the train into full emergency without warning, but all the issues with brakes applying differently or slack condition still apply regardless of how quickly the valve modulates.

We can't forget good old inertia.  No matter how quickly the shoes are applied to the wheels, a railcar is going to follow Newton's laws and keep right on going until the combined friction between the shoes, the wheels, and the rails is sufficient to have an effect on the car.  

I believe it's been reported that fifty cars derailed at East Palestine.  If ECP had cut that number in half, there still would have been a spill and a fire.

And, I go back to the well-known video of the train struck by a tornado.  It's very clear that the brake line had parted, which would initiate an emergency application throughout the train, yet the remainder of the train still piled into the trailing locomotive at a pretty good speed.  

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Posted by OldEngineman on Monday, February 27, 2023 8:01 PM

Dan posted: " If PTC turns out to be the thing that enabled a reduction in crew size, then it might - MIGHT - earn back it's cost some day."

Well, since most road crews are just two guys now (engineer and conductor), you're saying that going to "engineer-only" crews will be the solution that permits PTC to "earn back its cost" ???

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Posted by jeffhergert on Monday, February 27, 2023 10:48 PM

OldEngineman

Dan posted: " If PTC turns out to be the thing that enabled a reduction in crew size, then it might - MIGHT - earn back it's cost some day."

Well, since most road crews are just two guys now (engineer and conductor), you're saying that going to "engineer-only" crews will be the solution that permits PTC to "earn back its cost" ???

 

Not just one person, they're already chomping at the bit for no man crews. PTC and the EMS auto throttle move that goal so much closer. So they think. 

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Posted by oltmannd on Tuesday, February 28, 2023 6:59 AM

tree68
We can't forget good old inertia.  No matter how quickly the shoes are applied to the wheels, a railcar is going to follow Newton's laws and keep right on going until the combined friction between the shoes, the wheels, and the rails is sufficient to have an effect on the car.  

You're going to fail your Physics class!  :-)

Brake shoe force develops pretty quickly.  If that force is equal to 20% of the car's weight, than you're going to decelerate at 1/5g or 4 mph/sec.  The weight of the car is irrelevant.

The reason trains "take a mile to stop" isn't inertia or train weight, it's that brake systems are set for empty cars.  An empty that can do 4 mph/sec deceleration can only do 1 mph/sec loaded.  If the brakes were set for loaded cars, that train could reduce stopping distance from 1 mile to 1/4 mile.

 

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Posted by oltmannd on Tuesday, February 28, 2023 7:08 AM

jeffhergert

 

 
OldEngineman

Dan posted: " If PTC turns out to be the thing that enabled a reduction in crew size, then it might - MIGHT - earn back it's cost some day."

Well, since most road crews are just two guys now (engineer and conductor), you're saying that going to "engineer-only" crews will be the solution that permits PTC to "earn back its cost" ???

 

 

 

Not just one person, they're already chomping at the bit for no man crews. PTC and the EMS auto throttle move that goal so much closer. So they think. 

Jeff

 

I think they are chasing the wrong goal! (again)  A slow train with a "no man crew" is still a slow train. It consumes a huge number of locomotive and car hours to go "not very far".

How about trying to lengthen the crew districts by squeezing out all the time not moving or moving at resticted speed?  Two men going 300 miles should be cheaper and more valuable than "no men" going 120 miles.

FWIW Amtrak's Autotrain does 800 miles on two crews over frt RR territory with max speed of 70 mph and "freight braking" system (no graduated release) and about 2 HP/ton.

-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/

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