The future of wayside signals

[CGW]

With PTC on the horizon possibly becoming standard in years to come, does anybody think that wayside signals will disappear like the caboose, train orders, etc?

Jeff

[tomikawaTT]

Clear back in the dark ages when the Pennsy was a moneymaker, there were cab signals on their locomotives.  The big round position light wayside signals were still there when CSX and NS dissected the bones of Conrail.

Given that rail companies are (or claim to be) obsesso about safety, the wayside signal is available as a backup if the in-cab signal meets Mister Murphy...

Chuck

[tree68]

As a step beyond tomikawaTT's assessment (which is right on), methinks that lineside signals will disappear only when the alternatives have proven without a doubt that they are accurate and reliable and provide a positive economic impact.  (Or someone decides to mandate such a move).

Lineside signals do so much more than signify track occupancy.  Visit any major junction for an illustration. 

ATCS is a step in that direction, especially if it is coupled with PTC.  Right now ATCS simply indicates (at least what the railfan can determine) that something is lined to go from someplace to someplace else.  That will probably need to be refined.

Bottom line - never say never, but don't hold your breath.

[petitnj]

Wayside signals will disappear more quickly than most imagine. The vulnerability and maintenance of the wayside system will set them up for termination if they can be replaced with some system robust and isolated enough to satisfy railroad demands. We can feed direct track maps to the locomotive and show the position of switches and opposing traffic easily. Getting data to the field will require a separate cell phone like system that won't crash when some power line comes down or a disaster causes everyone to call their uncle to see how they are doing. Because the present railroad system is isolated from the public phone/internet/cell system now, the railroads are safe from most "cell" outages. What may be necessary is to build a separate cell network for critical transportation, emergency and utility systems that is not affected by the normal cell system. The emergency services are building a system now that interconnects police, fire, ... but will some vendor make such things available to the airline, utility and rail industry? This will then provide a shared (and much less expensive per user) system that will work for many different industries. Satellites and ground based systems can provide this service, but presently each industry is forced to build their own robust system and use the cell phone system when it is working. For just a few $billion I would be glad to build this new robust system.

[BaltACD]

I suspect wayside signals will continue to exist far longer than the 'techies' believe they will.  There needs to be a 'fall back' position for failure of the high tech PTC equipment...and it WILL fail.  Without a fall back position to allow for equipment failure, especially failure mid-trip, the train would be 'blind' and unable to proceed.  Wayside signals provide this fall back position.

[Deggesty]

What lines with cab signals have had the wayside signals removed?

Johnny

[CShaveRR]

The former C&NW main line did well without the intermediate signals--ATC and cab signals handled train spacing. However, distant and home signals for interlockings were always present. Since I hired out, CNW removed several interlockings (crossovers) from its mainline CTC between West Chicago and Nelson, and the signals went with them.

UP, on the other hand, is installing intermediate signals in places where it's upgrading the line. The ATC and cab signals remain, but are supplemented with lineside signals anywhere that UP has installed a new track or CTC on the old ones.

I'm assuming that the only functions they serve are to provide redundancy in the event of ATC failure (it's a pretty old and primitive system), and to provide a way to move equipment that is not equipped with ATC. And, as has already been pointed out, they convey route to be taken as well as block occupancy.

PTC/ATCS will have to be installed only on lines that meet certain criteria (e.g., passenger service, hazmat transport), but it is presumed that all locomotives will operate on these lines at one time or another, so they all will need to be equipped.

Block occupancy may not require signals once PTC/ATCS has been instituted and proven. But I submit that signals will still be necessary to provide information about which route will be taken. Although the new system may stop you if you don't have the proper route lineup, it would be nice to have some information about just which route this is.

[Railway Man]

CGW

With PTC on the horizon possibly becoming standard in years to come, does anybody think that wayside signals will disappear like the caboose, train orders, etc?

Jeff

 

They already are.  Railways are postponing as much as possible capital projects to replace old wayside signal systems, or install new signaling systems in dark territory, in the expectation that digital direct-to-cab transmission of train-control information will eliminate the expense to purchase, maintain, and later put-up with the malfunctions of wayside signal systems.

Whether that is the best decision the Class 1s could make I will leave to others with more knowledge than I to opine on.  I only am reporting what I know of the decisions being made by my colleagues in the Class 1s, who do not seem to be of the opinion that the safety, reliability, or human-factors effects of removing the wayside hardware will have a negative cost-benefit ratio.

If these plans continue unchanged, I do not think it will not be a rapid transition to a world without wayside signaling, but more like 20 years.  The capital cost and manpower requirements for conversion are high.  Lines where the existing signal system is very old and unreliable, where new capacity is needed, or where someone else is paying the bill, will likely be the first to be converted. 

RWM

[oltmannd]

Conrail did some cab signal projects where some of the benefit was the elimination of wayside intermediate block signals. Only the distant and home signals at interlockings were left.

[aricat]

This year BNSF just spent the spring and summer putting in a new signal system for the Northstar commuter system. It replaced all the searchlight signals with brand new color light system. I don't think BNSF would have spent the money if it was not needed. The new system is also lit 24/7 which is new for BNSF on this line. They act like it will be around as long as the searchlight signals were.