Question about a signal showing Restricting

Under what circumstance would a signal show Restricting? I know the train must proceed at restricted speed. The only signals I've seen so far that can show that are on Amtrak's Keystone Corridor. But I've never seen one show it.

Restricting can be used to allow the next train to close up behind a train already in that track segment (call-on). It displays at CTC signals where the dispatcher has cleared the train to pass that point but the rail ahead is not clear (perhaps due to detected equipment on the track or broken rail). And I've seen it used where trains are being sent to non-signaled track.

Depending on the line in question restricting can be displayed with a lunar white light or a flashing red ... so it is possible (depending on the line) for any signal that can display stop to display restricting. Also on most lines intermediate signals are technically "restricting" (not "stop") when they are solid red.

On lines where lunar is used I'd look for reasons such as unsignalled track or places where two trains could occupy the same signal section.

I thought a signal will show stop and proceed only if there is a train in the block. Not restricting.

Lackawanna565 wrote:I thought a signal will show stop and proceed only if there is a train in the block. Not restricting.

I've seen restricting several times due to a train in the next block. (CTC signals where the dispatcher fleeted the signal.)

Rules can vary ... what you're reading as a "stop and proceed" may be considered "restricting" depending on the rule book and the signal.

I doubt that there is one all-inclusive reply to a question like this, and the NTSB Accident Investigation linked below should serve to illustrate why:

http://www3.ntsb.gov/publictn/2009/RAR0901.pdf

In the instance cited above the crew of the following train apparently confused the restricted speed mandated by the signal inquuestion with a less-restrictive aspect to which they were more accustomed.

Historically, different railoraods have developed different signal systems; while the basics arpretty much the same, and it would be hard to confuse an absolute "Stop" from a "Clear/Proceed" on any line. there is a fair abount of leeway in the interpretation of the apects in between, as demosntrated by the three examples taken from the same site, and listed below:

Restricted Speed -- Proceed preparing to stop short of train, obstruction, or anything that may require the speed to be reduced, but not exceeding 15 MPH also see Limited Speed, Maximum Authorized speed, Medium speed, Slow speed

Restricted Speed (B&O/53) -- Proceed, prepared to stop short of: train, obstruction, improperly lined switch, or broken rail.

Restricted Speed (CCOR) -- Proceed prepared to stop short of train, engine, obstruction, or switch not properly lined, looking out for broken rail or anything that may require speed of a train or engine to be reduced, but not exceeding 20MPH.

A link to the site itself is also included':

http://www.railroadsignals.us/basics/basics3.htm

And as previously pointed out, a full stop may, or may not be involved before proceeding at restricted speed is permitted.

The most important aspect of traveling at restricted speed is the ability to stop. While 20 MPH is the usual maximum, most of the rulebooks I've read want the train to travel at a speed where it can stop within 1/2 of sight distance - on curves, at night and in inclement weather that can be slower than 20 MPH. Especially when one is looking for broken rail.

Intermediates displaying red are often only restricting. Absolutes in ABS or controlled points in CTC require specific permission to pass (instructions available in the rulebook the railroad in question is following).

I believe this thread started with a question about signals showing a unique restricting aspect (such as Lunar White on a system that uses that for restricting, or the position signal for restricting). How restricting is being potentially displayed on the specific line in question has not been revealed - although if there is a specific indication possible I'd look for one of the reasons I mentioned in my first reply (call-on or unsignalled track).

Under what circumstance would a signal show Restricting?
When the train should proceed at restricted speed.

Generally, the dispatcher has no control over what the signals actually display. The disp can only bring up the route that he wants the train to go. The logic in the signal system determines what the signals will show.

So yes, basically if a restricting is showing, its there for a reason.

It can be a lost off current in the track, a "track circuit" or a TOL - "Track Occupancy Light" which basically, the singal system thinks there is a train ahead, but there isn't, for example, or maybe an actual train ahead. Some signals show a stop and proceed when there is a train in the next block, others show restricting, and some railroad rules, allow a stop and proceed to be taken as a restricting. If its a stop and proceed, you are stopping, adn then proceeding at restricted speed. A restricting means you don't have to stop, but still have to proceed at restricted speed.

There are also cases, when the signal system is set up to display a restricting if there is a track condition ahead - maybe washout sensors or slide sensors, or less dramatic, a sharp crossover, with a slow speed. My RR has a set of crossovers at an interlocking that are maximum 10mph. So when crossing over there, they give you a Restricting. You also get a Restricting sometimes going into a yard or diverting off of signaled territory.

Its really dependent on the location and the railroad, but the important thing is that Restricting is a METHOD of operation where there are limits to how fast you can go, but you HAVE TO stop in half the visbile distance. if its really foggy and you can't see more than 3 feet in front of you, you go as fast as you need to to be able to stop in 1.5 feet.

In the Amtrak forum, there is a discussion about how a few weeks ago, a UP train "kissed" the Zepher, while the Zepher was stopped while they were clearing snow ahead. The UP engineer violated Restricted Speed. He did not stop in 1/2 the visible distance, and coupled up to the train ahead. Could have been much much worse, thank god it wasn't, but thats a perfect example of when you are operating under Restricted Speed, what you DON'T do.

For the scheme I'm familiar with (one of many out there), an absolute signal can't display STOP AND PROCEED and an intermediate signal can't display STOP. STOP requires the absence of a number plate on the signal and STOP AND PROCEED requires its presence - no way for the same signal to do both.

STOP AND PROCEED usually occurs when the block ahead is occupied (or has a broken rail, broken bond wire, short circuit, etc.) RESTRICTING can be due to that (as it was in the Amtrak crash), but more often it is due to the fact that you are about to enter onto a track where ALL movement must be done at restricted speed. For instance, suppose you're on the main and you're approaching a control point where you can go into a yard. A PROCEED means you're going to continue on the main, while a RESTRICTING means you're headed for the yard.

In theory it might make sense to display a STOP AND PROCEED at an absolute if the block ahead is known to be occupied and a RESTRICTING if the track ahead is restricted territory. Apparently that has never been considered important enough to invent a STOP AND PROCEED aspect that can be displayed on an absolute signal.

Dan

The line in question, Amtrak's Harrisburg (Keystone) line, is former PRR and position light signals are in use and are capable of displaying both Restricting and Stop and Proceed aspects at interlockings.


Thinking about this further, with the new colorized position light signals being installed, the S&P is probably not available, as I think the center lamp is not present, even on the lower arm.

That's a good point -- I never thought of looking to see whether those new signals have a neutral light on the bottom arm. I know the PRR used to display Stop & Proceed regularly at places like North Philadelphia to enable a train to get out of the platform immediately behind a preceding train even though the block was occupied, because the cab signal would clear up as soon as the block did, gaining a little time over waiting at the platform until it cleared. B&O CPL signals had the same provision, using either the top or bottom white marker light in conjunction with red. I believe the N&W was the exact opposite of the PRR, using the bottom marker or neutral light for stop, and its absence for stop and proceed.

http://www.youtube.com/watch?v=s0vB6H7xhqM

Well, after viewing this video on youtube, at 1:50, train passing EBHS at LEAMAN, signal changes from CLEAR (with a flickering 90 lamp ) to STOP & PROCEED, lunar marker lit. Signal is obviously fleeted.

Later, at 2:48, at RHEEMS, we see the signal progression, S&P, APP, APP LIMITED, CLEAR. Very nice. The circular backround on the lower arm is interesting.

I shoot that video. I wonder why that signal shows approach limited and the other one their I saw going through it's aspects doesn't. The only thing I could think of is the distance to the next siganls.

quite a few rules violations in that video as well.

1)The first push-pull set at Irishtown started blowing for the crossing less than 15 seconds prior to occupying the crossing.

2) The push-pull set at Lancaster blows two longs a short and a long (Norac Rule 19b) for the MofW personnel as opposed to one long and a short followed by successions of 2 shorts until past all men and equipment (Norac rule 19D).

Sorry, just observations.

Also, noticed the first push-pull at Leamans has a marker light out on the engineer side of the meatball.


As for the signal progression, as stated the signal came in right away as a Stop & Proceed because the signal was "fleeted". Obviously since it went from Approach to Approach Limited it must also act as a distant signal to another interlocking.

CSX Conductor wrote:Obviously since it went from Approach to Approach Limited it must also act as a distant signal to another interlocking.

Actually, it probably means "three block signalling" territory.

NJT uses that three block signaling a lot of places as well- a lot of signals have 2 heads (not just distant signals) and the signal progression behind a passing train is stop and proceed, approach, approach limited, then a clear. an approach limited doesn't always mean its a distant to an interlocking.

Always has to be an * hahaha