Trains.com

Mainline Steam and PTC

3971 views
12 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    December 2007
  • 1,307 posts
Mainline Steam and PTC
Posted by Falcon48 on Friday, August 7, 2009 9:11 PM

OK, here's a question for the steam and signal techies that may be on this site. 

On July 21, FRA published proposed rules on the installation of positive train control (PTC) on many main line routes, as required by recent Federal legislation.  Briefly, the rule requires installation of PTC by 2015 on any Class I routes which (i) carry intercity or commuter passenger trains, or which (ii) carry 5,000,000 GTM and have any toxic by inhalation (TIH) traffic.  FRA estimates that this will require PTC on about 69,000 route miles of main line track which, it says, comprise the "heart" or "core" of the Class I freight network. The rule will require the lead loco on any train operated on a PTC line to be PTC equipped (with some exceptions not here relevant). While the presence of excursion passenger trains on a line will not trigger a requirement to install PTC on that line, an excursion passenger train that operates on a line that is PTC equipped will have to be equipped. 

Mainline steam excursions typically operate on major Class I mainlines, so it is likely they will be operating on lines which will be PTC equipped by 2015.  That leads to my question.  Is it even possible to equip a steam locomotive with PTC?  Has anyone in the mainline steam camp even looked at this issue?  Inquiring minds want to know.

I'm posting the same question on the preservation forum.  

 

 

  • Member since
    December 2007
  • 1,307 posts
Posted by Falcon48 on Friday, August 7, 2009 9:15 PM

I'm getting old.  I said I would post the same question on the preservation forum, but then realized that this IS the preservation forum.  Obviously, I've reached the point in my dotage where I need to be taken away some place where I can spend my remaining years drooling on a food tray.

  • Member since
    October 2008
  • From: Calgary
  • 2,047 posts
Posted by cx500 on Saturday, August 8, 2009 12:45 AM

Falcon48

OK, here's a question for the steam and signal techies that may be on this site. 

.....

Mainline steam excursions typically operate on major Class I mainlines, so it is likely they will be operating on lines which will be PTC equipped by 2015.  That leads to my question.  Is it even possible to equip a steam locomotive with PTC?  Has anyone in the mainline steam camp even looked at this issue?  Inquiring minds want to know.

 

British steam engines that are cleared for main line running in that country have had to be equipped with various modern train control equipment.  While I assume their requirements differ in certain details from proposed North American style PTC, I'm sure it can be done.  It will, however, be yet another cost that the operator will have to recover through fares on charter trips and admission to special events.  Pulling a number somewhat out of the air, figure on at least $50,000 per steam locomotive.  Whoever attempts the first application will pioneer the engineering and that will push their costs even higher..

John

  • Member since
    December 2007
  • 1,307 posts
Posted by Falcon48 on Saturday, August 8, 2009 8:25 AM

FRA is estimating the cost for installing PTC on a standard diesel locomotive to be around $55,000.  I imagine, based on your note, that the cost for a custom designed installation for a steam locomotive (if a special design is required) would be higher than this, if it can be done at all. 

The reason for my question of whether it can be "done at all" relates to the way PTC functions and whether those functions could even be performed on a steam locomotive.  Now, here is where my ignorance steps in.  I don't really know how the new PTC systems will interface with locomotive controls.  If they interface with the locomotive only through the brake system (or, for a steam loco, can be made to do so), then it should be theoretically possible for the system to work on steam locos.  After all, many steam locos had older ATC and ATS systems, and that's the way they worked.  But if PTC needs to automatically control or monitor the throttle function to work properly, there would seem to be a problem.

I wonder whether the mainline steam people have looked into this, or whether they are even aware of it.

  • Member since
    December 2007
  • 1,307 posts
Posted by Falcon48 on Saturday, August 8, 2009 9:08 AM

One addition to my immediately preceding post.

To my knowledge, mainline steam trains these days nearly always include a diesel trailing right behind the steam locomotive (I'm not sure, however, whether there is always an engineer on the diesel).  That suggests a possible compliance strategy.  Even though the proposed rule, as currently written, requires the lead loco of a train to be PTC equipped when operating on a PTC line, it occurs to me that FRA might permit steam locos which were not fully equipped to operate if the trailing diesel is fully equipped.  I imagine that, under this approach, the steam loco would still have to have some PTC functionality (for example, the system would probably need to "see" the location of the lead loco to function properly), but the expensive stuff could be on the diesel (and hopefully be just a standard PTC apparatus).

Now, I don't know how this would work, or whether FRA would even accept it (assuming the rule is adopted as presently proposed, this approach may require a subsequent rule change or a waiver).  I'd be interested in any reactions from the techies on this forum.

  • Member since
    December 2007
  • From: Cedar Rapids Iowa
  • 12 posts
Posted by rfdatalink on Saturday, August 8, 2009 9:18 AM

As with most things I'm sure it can be done, but the cost it is the question.

PTC as the major freight railroads are implementing it now does not need to control the throttle.    Right now the only thing the PTC initiates is a full service brake application.   In the future an emergency application may also be possible.  

A diesel locomotive will automatically back the trottle off to idle when such a brake application occurs.   I don't know if there is an equivalent function on a steam locomotive.

On a diesel the PTC system uses the throttle position as input to the speed prediction algorithm.    This is needed to predict if the train will stop or be under proscribed speed by a certain point.    I'm sure this could also be done on a steamer, but a new algorithm that takes into account throttle position, johnson bar position, and boiler pressure would be necessary.  

One last item that could be an issue is the user interface.    PTC systems now being implemented need a display screen for crew interaction.   How and where such a screen would be installed without ruining the "historical accuracy" of the locomotive would be a question.

 Stephen

 

  • Member since
    February 2005
  • From: Vancouver Island, BC
  • 23,330 posts
Posted by selector on Saturday, August 8, 2009 11:08 AM

It should be quite straighforward....this from a distinctly non-engineering type.  The throttle is held in place on its sector plate by a detent pawl.  That pawl would be solenoided to withdraw freeing the throttle to move forward or backward with normal hand control.  At the same time, bolted to the side of the existing sector plate, is a slightly recessed version of that plate.  Gear-toothed and all.  Mounted on the throttle arm will be a small motor and gear controlled by a microchip (model railroad decoder, for example )  that will forceably run the throttle bar back towards the front/off position.  Meanwhile, the normal PTC braking functions are taking place.

??

-Crandell

  • Member since
    January 2001
  • From: Canada
  • 509 posts
Posted by cprted on Saturday, August 8, 2009 12:50 PM

rfdatalink

One last item that could be an issue is the user interface.    PTC systems now being implemented need a display screen for crew interaction.   How and where such a screen would be installed without ruining the "historical accuracy" of the locomotive would be a question.

As it stands now, steam locomotives carry plenty of non-period correct gear.  Diesel MU controls, radios, event recorders, ditch lights, etc etc ...  PTC will simply be one more thing to add to the list. 

The grey box represents what the world would look like without the arts. Don't Torch The Arts--Culture Matters http://www.allianceforarts.com/
  • Member since
    July 2006
  • From: Central New York
  • 335 posts
Posted by MJChittick on Saturday, August 8, 2009 9:38 PM

Does anyone know if we have any forum members affiliated with the Union Pacific Steam Program?  I feel it's likely that UP is already in the advanced planning phase for how PTC will be applied for 844 and 3985.

 Did anyone attending Railfest 2009 discuss this matter with any crew members from 4449, 1225 or 765?

Mike

  • Member since
    December 2007
  • 1,307 posts
Posted by Falcon48 on Monday, August 10, 2009 10:48 PM

First of all, thanks to all who have responded to my original post.  I didn't raise this issue just out of personal curiousity.  I have some involvement in tourist railroad issues, and also in Class I PTC implementation.  I made the posting because it is obvious to me, from my Class I work, that the PTC rules will impact mainline steam, but I haven't been able to get clear answers on whether the mainline steam community has considered the potential imact of these rules or is even aware of them.  I wanted to get at least some understanding of whether it was possible to equip a steam loco with PTC (based on the answers to my post, it is), and I know from prior postings that there are people in this and other forums who appear to have signal and train control expertise. 

I. too, would be interested in whether the people involved in the UP steam program (or other main line steam programs) have looked into this.  I wouldn't necessarily assume that they have.  The whole PTC issue has developed very quickly, and the people who know a lot about PTC on the individual railroads may not be the people who think much about steam operations.

  • Member since
    December 2007
  • 1,307 posts
Posted by Falcon48 on Monday, August 10, 2009 10:56 PM

selector

It should be quite straighforward....this from a distinctly non-engineering type.  The throttle is held in place on its sector plate by a detent pawl.  That pawl would be solenoided to withdraw freeing the throttle to move forward or backward with normal hand control.  At the same time, bolted to the side of the existing sector plate, is a slightly recessed version of that plate.  Gear-toothed and all.  Mounted on the throttle arm will be a small motor and gear controlled by a microchip (model railroad decoder, for example )  that will forceably run the throttle bar back towards the front/off position.  Meanwhile, the normal PTC braking functions are taking place.

??

-Crandell

  Is there any particular reason why PTC would have to shut off the throttle on a steam loco?  Muy understanding is that the older ATC and ATS systems didn't shut down a steam loco throttle when they imposed a penalty brake application, and it's unclear to me why a PTC penalty brake application would have to do so.  There's no way the engine would be able to overcome a train brake application.  My guess is that the feature of diesels which shuts down the throttle when the brakes are applied has more to do with the internal workings of the locomotive than with effectiveness of the brake application.
  • Member since
    February 2005
  • From: Vancouver Island, BC
  • 23,330 posts
Posted by selector on Tuesday, August 11, 2009 12:26 AM

I don't know the answer.  I am not a steam driver.  I was addressing the question prima facie, and not questioning the premise.  I know that steamers are very torquey and will spin their drivers if the cut-off is in the right setting and the throttle is pulled fully back if the rest of the consist becomes highly resistant to forward motion...as it would on a suddenly heavy grade, for example.  I would expect a full application or an emergency application to have the same effect.  I could only guess that spinning drivers allowed to go too long could not be a good thing...sliding steel on steel?  I hope a steam hogger will help you out.

-Crandell

  • Member since
    June 2002
  • 20,096 posts
Posted by daveklepper on Tuesday, August 11, 2009 8:58 AM

There is plenty of history to go on with regard to this matter.   The Pnnsy and certain of  its subsidiaries, such as the LIRR, had steam with cab signals and a more primitive form of automatic train control and train stop, that would automatically apply brakes if a restrictive signal was passed at greater than signalled speed.   The New Haven had a simpler version for automatic train stop if passing a red signal.

Join our Community!

Our community is FREE to join. To participate you must either login or register for an account.

Search the Community

Newsletter Sign-Up

By signing up you may also receive occasional reader surveys and special offers from Trains magazine.Please view our privacy policy