Positive Train Control in US by 2015- is there a better way?

[ostlandr]

The US is going to implement Positive Train Control (PTC) technology by 2015, or so the government mandate says: http://www.aar.org/Safety/~/media/AAR/P ... 02009.ashx

It's going to hurt the Class 1 railroads, really hurt the mid-sized railroads, and just about kill the short lines. Tourist railroads may vanish, since PTC is mandated for any passenger railroad. Also, some short line and regional railroads may find it cheaper to refuse to ship cargoes like chlorine, anhydrous ammonia, etc., which will force these cargoes onto highway trucks.

There's got to be a better way to do this, one that won't bankrupt the small railroads. I've got some ideas on how to build a low-cost PTC system using a combination of RFID and cellular technology. Thought I'd see if anybody here has any input on the ideas.

The basis of the system is putting active RFID tags on locomotives, and having signals which interact with both the locomotives by RFID and each other by cellular technology. Since most US short lines and a lot of other railroad lines are single track, the signal system will establish a path from one safe waiting location (siding) to another- sound familiar? The signals would communicate with each other via existing cellular frequencies, either directly or indirectly. This would require a fail-safe system that would change the signal to red if it lost communication with its neighboring signals. Each signal mast would be self-powered, with a solar panel and/or a micro wind turbine charging a battery. Not having to run cables along the ROW and connect them would be a huge savings.

The locomotive RFID tags would tie into the locomotive control system. This would provide cab signals, and enforce signals, speed limits, etc. Speed limit and yard limit signs, whistle posts, etc. could have simple passive or battery-boosted RFID tags coded for their info- they could automatically trigger the locomotive horn, restrict speed, etc. For a temporary speed restriction, the maintenance crews could just drop temporary signs with the correct tag. The signals would interact also- trigger the brakes if the engineer passes a red signal (SPAD to the UK folks) or enforce restricted speed, etc. The system might require another RIFD tag on the end of train (EOT) device to let the signals know when the train is in the clear.

So, sound like a workable idea? Please, play Devil's Advocate if you can.

[audigex]

Anyone wondering if they'll use OTTD as the engine for this?

I'm not sure why you think it's going to kill so many different railroads though? RFID is reasonably cheap compared to the cost of a locomotive. I say reasonably cheap, I actually mean stupidly cheap. The software might be a bit more expensive, but it's still not going to be an insane cost. I don't see how it's going to do so much damage.

I've not read that link: What have chlorine, anhydrous ammonia etc got to do with the signalling system?

[SD89MAC]

I thought tourist railways and shortlines would be exempted from this.

[Dave]

RFID Tags! My uni library runs that system! Can't imagine it'll be the small sticker that's in every book!

[Kevo00]

Hmmm...can't help thinking this is just a bit of Republican scaremongering about regulation costing the industry millions, etc. etc.

[LaSeandre]

The US is going to implement Positive Train Control (PTC) technology by 2015, or so the government mandate says: http://www.aar.org/Safety/~/media/AAR/P ... 02009.ashx

It's going to hurt the Class 1 railroads, really hurt the mid-sized railroads, and just about kill the short lines. Tourist railroads may vanish, since PTC is mandated for any passenger railroad. Also, some short line and regional railroads may find it cheaper to refuse to ship cargoes like chlorine, anhydrous ammonia, etc., which will force these cargoes onto highway trucks.

There's got to be a better way to do this, one that won't bankrupt the small railroads. I've got some ideas on how to build a low-cost PTC system using a combination of RFID and cellular technology. Thought I'd see if anybody here has any input on the ideas.

The basis of the system is putting active RFID tags on locomotives, and having signals which interact with both the locomotives by RFID and each other by cellular technology. Since most US short lines and a lot of other railroad lines are single track, the signal system will establish a path from one safe waiting location (siding) to another- sound familiar? The signals would communicate with each other via existing cellular frequencies, either directly or indirectly. This would require a fail-safe system that would change the signal to red if it lost communication with its neighboring signals. Each signal mast would be self-powered, with a solar panel and/or a micro wind turbine charging a battery. Not having to run cables along the ROW and connect them would be a huge savings.

The locomotive RFID tags would tie into the locomotive control system. This would provide cab signals, and enforce signals, speed limits, etc. Speed limit and yard limit signs, whistle posts, etc. could have simple passive or battery-boosted RFID tags coded for their info- they could automatically trigger the locomotive horn, restrict speed, etc. For a temporary speed restriction, the maintenance crews could just drop temporary signs with the correct tag. The signals would interact also- trigger the brakes if the engineer passes a red signal (SPAD to the UK folks) or enforce restricted speed, etc. The system might require another RIFD tag on the end of train (EOT) device to let the signals know when the train is in the clear.

So, sound like a workable idea? Please, play Devil's Advocate if you can.

Sounds like a bit of RETB and a bit of ERTMS. In theory, workable!

[ostlandr]

Thanks for the links! My idea is pretty much ETCS level 1 with the cab signals tied into the locomotive controls.

The signal system is designed to use the existing cellular telephone network rather than a proprietary network. Basically, when a train passes a signal, the signal sends a data burst (text message) to the next signal in the line. If that's not a safe waiting location (for example, an intermediate signal on a single-track line) the signal passes the data on to the next signal, and so forth until the "path" ends at a safe waiting location such as a siding or the main line parallel to it. For a more advanced system, the signals could send a second data burst to a dispatcher- "train 00034 passed signal 33321 westbound at 56 mph."

The plan is to use as much COTS (Commercial Off-The-Shelf) tech as possible- a "smart phone" would be a perfectly good signal controller, and RFID tags can already be used for telemetry: http://en.wikipedia.org/wiki/RFID#Telemetry

Sounds like a bit of RETB and a bit of ERTMS. In theory, workable!

[ostlandr]

The latest cost estimates I've seen have it costing the railroads an entire year's capital spending. Doable, but that's another year of deferred capital investment in infrastructure.

Hmmm...can't help thinking this is just a bit of Republican scaremongering about regulation costing the industry millions, etc. etc.

[ostlandr]

The cheap, cellular-and-RFID system is just an idea of mine so far. The proposed FRA compliant systems I've seen are much more complex.

Basically, if your short line hauls extremely hazardous chemicals and/or carries passengers, you have to install a full PTC system.

Anyone wondering if they'll use OTTD as the engine for this?

I'm not sure why you think it's going to kill so many different railroads though? RFID is reasonably cheap compared to the cost of a locomotive. I say reasonably cheap, I actually mean stupidly cheap. The software might be a bit more expensive, but it's still not going to be an insane cost. I don't see how it's going to do so much damage.

I've not read that link: What have chlorine, anhydrous ammonia etc got to do with the signalling system?

[Dave]

You wouldn't be able to use RFID in the public form that we see as its just not accurate enough. Where a signal system might need to know if a train is in a specific position, RFID can be up to 50 feet out. That's the difference between a train fouling the main line and not fouling the main line.

This is why the library wasted their money. They said using a scanner they'd be able to see where a book was in the library. Not the case. They could just about tell if a book was in a run, which meant it could be one of 500 books.

If they were to roll out RFID, it'd have to be muchhhhhh more accurate than that.

[John]

They will be installing an RFID system at work to track components. It will have an accuracy of around 10-20 ft (or rather it will need to, and giving the money they are spending, it will do).


And if you know the limitations of the system you can use it reasonably well - you just adjust your tolerance levels to suit. The example above would simply say that a train within 50ft would be fouling both lines - not ideal, but it would work safely.

In crucial areas the accuracy could also be increased with more accurate sensors.


And Dave that technology does work in libraries, you just need to ensure you have a suitable number of antennas to give you the accuracy.


I would be more worried about the reliability of cellular networks...

[welshdragon]

<snip> This is why the library wasted their money. They said using a scanner they'd be able to see where a book was in the library.

What happened to the good old Dewey decimal system? (or the stupid Academic one I can't for the life of me get my head around) If you are that reliant on technology then you might as well do away with the current libraries, have a counter in a small room and use a computer to request the book, issue it to your account and then read it for you...

Sorry, i've worked in Public Libraries enough to know that technology for locating books is as simple as looking up the shelfmark on Talis and then walking to the shelf and picking up the book, if it's not there you then... yeah, I'll shut up now.

[Kevo00]

But in University libraries students are often lazy and fail to put a book back when they have used it, or even worse hide books so that others can't get them. More of an issue is that somewhere like LSE has thousands of old, precious, books that they haven't even barcoded because no one ever takes them out and someone could easily simply steal them by walking right out of the door with them...

[Dave]

<snip> This is why the library wasted their money. They said using a scanner they'd be able to see where a book was in the library.

What happened to the good old Dewey decimal system? (or the stupid Academic one I can't for the life of me get my head around) If you are that reliant on technology then you might as well do away with the current libraries, have a counter in a small room and use a computer to request the book, issue it to your account and then read it for you...

Sorry, i've worked in Public Libraries enough to know that technology for locating books is as simple as looking up the shelfmark on Talis and then walking to the shelf and picking up the book, if it's not there you then...

You then what? Kevo has it spot on. Lazy students, etc.

[Dave]

Incidentally, UCLan's entire book collection - including all law reports (dating back to 1890s) are now RFID tagged.

[ostlandr]

I think it's doable with RFID tags. The railroads already use passive RFID tags to track rolling stock.

With a rail line, the tags only have to be located accurately in one axis. The plan is, each end of a train will have a distinct tag. So, let's use a standard "Y" type diverging switch as an example. The area to be protected would be from just clear of the switch points on the bottom of the Y, to the points on the arms of the Y where a piece of equipment won't foul the other track. Starting with a clear switch, once a start/end tag passes an entrance to the Y, it is blocked until the second start/end tag passes an exit. If the system is only accurate to 20 feet, then locate the signal antennae 20 feet from the point that needs to be protected.
For a block of track, when a start/end tag passes a signal (would need to have some way for it to tell direction of movement- 2 antennae?) the block beyond it would be occupied until the second start/end tag passes the next signal.
Another possibility is to have the "front" and "rear" tags communicate- when the train is moving "backwards" the "rear" tag would become a "front" tag and vice versa. Then instead of counting tags, the signals would know the front of the train from the rear.

Not going for the ultimate here- just a bare-bones system to meet the PTC mandate, using as much COTS tech as possible and adhering to the KISS principle. If it accurately operates the signals without the need for track circuits, lets signals communicate with each other without running cables, communicates the signals to the cab, and can apply the train brakes if you pass a stop signal, that's what I'm going for.

They will be installing an RFID system at work to track components. It will have an accuracy of around 10-20 ft (or rather it will need to, and giving the money they are spending, it will do).


And if you know the limitations of the system you can use it reasonably well - you just adjust your tolerance levels to suit. The example above would simply say that a train within 50ft would be fouling both lines - not ideal, but it would work safely.

In crucial areas the accuracy could also be increased with more accurate sensors.


And Dave that technology does work in libraries, you just need to ensure you have a suitable number of antennas to give you the accuracy.


I would be more worried about the reliability of cellular networks...