Inside Metra's busiest interlocking...

So much to correct about Jersey_Mike's A-5 article. Unfortunately, I can't figure out how to post this as a comment to his Blogspot page (got an error) so I'll do it here.

Ownership: Metra owns all Milwaukee District track after leaving Amtrak's CUS tracks. A-2 and west is dispatched by CP (and appears in the CP employee TT) but is owned by Metra. As I understand it, the CP dispatchers pretty much let the Metra operators at A-2 and A-5 do their own thing since there is little freight traffic there.

Without a readable diagram, I'm not sure what signals and switches go with what numbers but if the 74R is the exit signal on track 3 heading eastbound to A-2 which you claim is fleeted due to reverse running being uncommon on that track, that is wrong. I believe seven outbound MD-W and NCS PM rush hour trains normally come out track 3 (including the two I am most typically on). Most cross to 1 or 2 on the crossovers on the Elgin leg on A-5 although two of them, 2237 and 2239, normally run track 3 all the way to B-12 (Franklin Park).

The removed 4th track you call a siding is actually the old MILW EB freight main. As I understand it, the Milwaukee was at one time four tracks from Bensenville yard all the way to Morgan (between CUS and A-2) arranged from North to South, 1-WB Psgr, 2-EB Psge, 3-WB Freight, 4-EB Freight. The City of Chicago auto impound lot across from the Western Ave. station and coach yard is the old freight yard. Track 4 still exists east of A-2 as an NS-owned (I assume - descended from PRR/Panhandle as the original owner of the A-2 to CUS tracks) industrial track to access one industry.

lstone19 wrote: Ownership: Metra owns all Milwaukee District track after leaving Amtrak's CUS tracks. A-2 and west is dispatched by CP (and appears in the CP employee TT) but is owned by Metra. As I understand it, the CP dispatchers pretty much let the Metra operators at A-2 and A-5 do their own thing since there is little freight traffic there.

Ownership charts I have seen indicate that beyond A-5 the tracks are either owned or more strongly operated by CP (ie maintained). If METRA owns more than just what is east of A-5 where is the property line as it is unlikely that Metra owns much/any track in Wisconsin. knew of the dispatching situation, but like you said it seems clear that METRA operators had operational control of the "Metra" portion of the line.

lstone19 wrote: Without a readable diagram, I'm not sure what signals and switches go with what numbers but if the 74R is the exit signal on track 3 heading eastbound to A-2 which you claim is fleeted due to reverse running being uncommon on that track, that is wrong. I believe seven outbound MD-W and NCS PM rush hour trains normally come out track 3 (including the two I am most typically on). Most cross to 1 or 2 on the crossovers on the Elgin leg on A-5 although two of them, 2237 and 2239, normally run track 3 all the way to B-12 (Franklin Park).

Well a few rush hour moves is the definition of uncommon. Less frequent moves would eventually be classified as "rare".

Jersey_Mike wrote:

lstone19 wrote: Ownership: Metra owns all Milwaukee District track after leaving Amtrak's CUS tracks. A-2 and west is dispatched by CP (and appears in the CP employee TT) but is owned by Metra. As I understand it, the CP dispatchers pretty much let the Metra operators at A-2 and A-5 do their own thing since there is little freight traffic there.

Ownership charts I have seen indicate that beyond A-5 the tracks are either owned or more strongly operated by CP (ie maintained). If METRA owns more than just what is east of A-5 where is the property line as it is unlikely that Metra owns much/any track in Wisconsin. knew of the dispatching situation, but like you said it seems clear that METRA operators had operational control of the "Metra" portion of the line.

Metra ownership ends just west of Big Timber Rd. station on the Elgin line, just west of Rondout on the C&M (where the Fox Lake line diverges), and just west of Fox Lake station. CP has operational control (i.e. dispatches the lines) but Metra maintains the line. I have no idea where you can find documentation of this.

lstone19 wrote: Without a readable diagram, I'm not sure what signals and switches go with what numbers but if the 74R is the exit signal on track 3 heading eastbound to A-2 which you claim is fleeted due to reverse running being uncommon on that track, that is wrong. I believe seven outbound MD-W and NCS PM rush hour trains normally come out track 3 (including the two I am most typically on). Most cross to 1 or 2 on the crossovers on the Elgin leg on A-5 although two of them, 2237 and 2239, normally run track 3 all the way to B-12 (Franklin Park).

Well a few rush hour moves is the definition of uncommon. Less frequent moves would eventually be classified as "rare".

We'll have to disagree on meanings. Reverse moves 3 are much more common than they are on 1 and 2. Outside of AM rush, everything goes in on 2 unless there's track work being done or a delay so fleeting 3 but not fleeting 2 seems odd.

What is the rationale behind not using 2 as the go to reversible track in favor of 3? I mean I was just going with what I saw in the pics and that are tracks 1 and 3 with fleeted exit signals and track 2 without. That implies 1 and 3, at least for whatever time of day it is, are not expecting reverse traffic.

Jersey_Mike wrote:What is the rationale behind not using 2 as the go to reversible track in favor of 3? I mean I was just going with what I saw in the pics and that are tracks 1 and 3 with fleeted exit signals and track 2 without. That implies 1 and 3, at least for whatever time of day it is, are not expecting reverse traffic.

According to the presentation, that's a correct observation for that particular time of day. But the A2 & A5 operators do "switch it up" during a portion of the afternoon rush (after 2242 goes east if my notes are correct) and track 3 indeed becomes the preferred "reversible" track. The main benefit to using 3 instead of 2 is that it allows Metra to speed up traffic through this location that would at times become a bottleneck, and resulted in minor delays to certain trains; especially when NCS first started. Specifically, it minimizes the use of the crossovers at the east end of A5, with only the crossovers on the west end (Elgin leg) used for 3 to 2 moves for the westward MDW/NCS express traffic as Larry mentioned. It also allows inbound MDN/Amtrak traffic coming off the C&M to highball in on 2 at A5 with no delays due to conflicting traffic, something that wouldn't always be possible if 2 were in use in both directions...

doepack wrote:

Jersey_Mike wrote:What is the rationale behind not using 2 as the go to reversible track in favor of 3? I mean I was just going with what I saw in the pics and that are tracks 1 and 3 with fleeted exit signals and track 2 without. That implies 1 and 3, at least for whatever time of day it is, are not expecting reverse traffic.

According to the presentation, that's a correct observation for that particular time of day. But the A2 & A5 operators do "switch it up" during a portion of the afternoon rush (after 2242 goes east if my notes are correct) and track 3 indeed becomes the preferred "reversible" track. The main benefit to using 3 instead of 2 is that it allows Metra to speed up traffic through this location that would at times become a bottleneck, and resulted in minor delays to certain trains; especially when NCS first started. Specifically, it minimizes the use of the crossovers at the east end of A5, with only the crossovers on the west end (Elgin leg) used for 3 to 2 moves for the westward MDW/NCS express traffic as Larry mentioned. It also allows inbound MDN/Amtrak traffic coming off the C&M to highball in on 2 at A5 with no delays due to conflicting traffic, something that wouldn't always be possible if 2 were in use in both directions...

I think another factor is the configuration at A-3 and A-2. Moves out of the yard can get to 1 or 2 at A-3 but need to go to the east end of A-2 to get to 3. Half the inbound traffic is coming out of the yard that time of day.

One problem is so many of those crossovers are 10mph. I believe all the crossovers at A-5 are 10mph. The ones on the Elgin leg are constrained by bridges so can't be lengthened (although Metra has some sort of construction project going on at A-5, it looks like it's just new signals). Maybe they should take a page out of the Rock Island playbook and run left-handed in the afternoon although that might just move the bottlenecks elsewhere.

All of the crossovers are 10mph except for the 33 crossover, which is 25mph. Trains routed through that "fast" XO always receive a "Restricting" to enter the plant, but of course, they are permitted to increase speed once the head end takes something more favorable at the exit signal at the west end.

The second photo on the page (from 2004) only shows two signal heads on the westbound signal on main 2, at the east end of the plant. This has since been upgraded to 3 heads, so westbound Elgin trains can go C&M 2 to Elgin 2 on a "diverging clear"/"diverging approach". It is interesting to note that, for consistency's sake, westbound 3-to-3 moves would still receive a "diverging" signal, even though they do not traverse any turnouts. I believe that has changed within the last few months, though: a permanent "15" advance speed sign has been installed to protect the curve.

So far as ownership goes: it is correct that both subdivisions are dispatched by CP, from A-2 (exclusive) on west. However, ownership/maintenance belongs to Metra, out as far as the respective ends of "dinky" territory (Rondout, Randall Road).

In the case of the C&M sub, the territory between Mayfair and A-5 is essentially "dispatched" by the operator at A-5, since he also controls the Grayland plant. In fact, the CP C&M Dispatcher's screen in Minneapolis normally only indicates track authorization/occupancy west of Mayfair.

A-5 does not have any control over the signals or switches at Mayfair; that interlocking is controlled completely by CY Tower. The information on the computer screen is provided to the A-5 operator for information only. In the rare case of crossing trains over at Mayfair - communication is needed between the C&M Dispatcher, A-5 operator, and CY operator, to establish an understanding of which moves are to be made.

EricL wrote: The second photo on the page (from 2004) only shows two signal heads on the westbound signal on main 2, at the east end of the plant. This has since been upgraded to 3 heads, so westbound Elgin trains can go C&M 2 to Elgin 2 on a "diverging clear"/"diverging approach".

I noticed that this morning as we came around the curve and I could see the signal bridge ahead of us. I have gone WB around the curve on 2. A crazy night (mentioned in another thread) where thanks to a broken switch, we had to around the SE connector on to the Bloomingdale, then back through the crossover on to 2, then around the curve on 2, and finally cross back to 1.

It is interesting to note that, for consistency's sake, westbound 3-to-3 moves would still receive a "diverging" signal, even though they do not traverse any turnouts. I believe that has changed within the last few months, though: a permanent "15" advance speed sign has been installed to protect the curve.

That is interesting. So whether I'm on a train that will cross to 1 after going around the curve or stay on 3 (2239 usually), they all get Diverging Clear (or Approach) and the engineer has to look ahead to see if we're crossing and he needs to slow from 15 (curve) to 10 (crossover)? Or does the stay on 3 get R/G/R and the cross after the curve get R/R/G? CP TT defines both as Diverging Clear. And the 15 slow to 10 is definitely what happens as that slowing to 10 is very noticeable on the train.

oh, you know what? I could be wrong. I didn't account for the fact that those westbound Elgin trains on 3 main could cross over. I always assumed those trains stayed on 3. I guess I could have found out otherwise by actually reading your posts.

Still, though, anytime we cross over (at all, either end of the plant) to continue up the C&M, it's always on a Restricting. A lot of times, during track work affecting #1, they'll run Amtrak out #3 to A-5, where we'll cross back over to C&M 1.

You can not get a R-R-G on any of these signals, although it would be nice if you could. Searchlights can only display a maximum of 3 colors per head. So the bottom head has, at best, red, lunar, and yellow; many times it's only red and lunar. It is possible to get around this limitation by using a "flasher" mechanism (hence using flashing red as the Restricting indication), but this practice didn't seem to be adopted by the CP/Soo. I've never seen a flashing red searchlight anywhere on our territory.

Restricting for anything except same track moves would fit with what Jersey Mike said in his A-5 article about exit signals. But it sounds like you're Amtrak. Engineer? If you ever run the 5:08 out of CUS, see what the home signal at A-5 on 3 is showing. 2235, the 5:05, goes 3 to 1 after going around the curve. Most days, the 5:08 passes 2235 before getting to A-5.

Regarding searchlight signals, what do I know? My experience is with PRR-style position light signals. that's why I like those signals east of A-2. But at least on those, I know the difference between Diverging Approach and Restricting.

Yeah, I have run that 5:08 plenty of times, and I know just the train you mean. They used to get a diverging signal at A-5. I haven't worked that job in forever though, hence why I'm unsure whether or not this has changed. But I guess you must be right about that setup on #3. I retract my previous statement....

One day, I had a particularly heavy train and a particularly laggardly engine - and that 2235, having left Western Ave behind me from a dead stop, easily breezed by us for a decent bit of distance! before he finally had to slow down. I watched him in the side window as he went by, picking up his radio mic: "that the best you got??" Not much I could say to that!

At any rate - someone else mentioned this too - they have been doing some preparatory work (pile driving, earth moving) in preparation for putting up new signal bridges. So I guess all of this will be a moot point before long. I wonder if they'll modify the interlocking at all? There've been rumors for years of remoting A-5's duties to someone else. Which is a horrible idea, of course, but you know... modern railroad management, and all that...

EricL wrote:All of the crossovers are 10mph except for the 33 crossover, which is 25mph. Trains routed through that "fast" XO always receive a "Restricting" to enter the plant, but of course, they are permitted to increase speed once the head end takes something more favorable at the exit signal at the west end.

That's utterly ridiculous. How poor was the Milwaukee road that it couldn't install proper medium speed turnouts and appropriate signaling to support them?

EricL wrote:A-5 does not have any control over the signals or switches at Mayfair; that interlocking is controlled completely by CY Tower. The information on the computer screen is provided to the A-5 operator for information only. In the rare case of crossing trains over at Mayfair - communication is needed between the C&M Dispatcher, A-5 operator, and CY operator, to establish an understanding of which moves are to be made.

Thanks, I figured that was the case, but dual key arrangements do exist so I mentioned the possibility.

EricL wrote:Still, though, anytime we cross over (at all, either end of the plant) to continue up the C&M, it's always on a Restricting. A lot of times, during track work affecting #1, they'll run Amtrak out #3 to A-5, where we'll cross back over to C&M 1.

You can not get a R-R-G on any of these signals, although it would be nice if you could. Searchlights can only display a maximum of 3 colors per head. So the bottom head has, at best, red, lunar, and yellow; many times it's only red and lunar. It is possible to get around this limitation by using a "flasher" mechanism (hence using flashing red as the Restricting indication), but this practice didn't seem to be adopted by the CP/Soo. I've never seen a flashing red searchlight anywhere on our territory.

This is why I cannot stand western style route signaling because everything is so wishy washy. In that track 3 example with a 10mph turnout and a 15mph straight speed you don't need a R/R/G (as seen on eastern roads) because even tho the turnout is Slow Speed, it is the only diverging route so it could be signaled R/G/R. Eastbound Elgin tks 1 and 2 should get a R/G/R onto the C&M, but they could be signaled G/R/R because it is the only (non-Restricting) route so the speed restriction is handled in the timetable. One of the reasons we're faced with such an impractical wireless based PTC technology is because western railroads have always been free to pick arbitrary turnout speeds like 10, 25, 18, whatever they want. In the east we use three speeds, 15, 30 and 40/45 and you can provide ATC for those with coded track circuits.

Restricting for anything except same track moves would fit with what Jersey Mike said in his A-5 article about exit signals. But it sounds like you're Amtrak. Engineer? If you ever run the 5:08 out of CUS, see what the home signal at A-5 on 3 is showing. 2235, the 5:05, goes 3 to 1 after going around the curve. Most days, the 5:08 passes 2235 before getting to A-5.

The presence of lower heads for Diverging indications implies that some turnouts are not Restricted speed only. The interlocking is just so inconsistently signaled that I doubt even the operators even know what certain routes will wind up displaying.

Regarding searchlight signals, what do I know? My experience is with PRR-style position light signals. that's why I like those signals east of A-2. But at least on those, I know the difference between Diverging Approach and Restricting.

Real PRR position lights do not display Diverging Approach.

At any rate - someone else mentioned this too - they have been doing some preparatory work (pile driving, earth moving) in preparation for putting up new signal bridges. So I guess all of this will be a moot point before long. I wonder if they'll modify the interlocking at all? There've been rumors for years of remoting A-5's duties to someone else. Which is a horrible idea, of course, but you know... modern railroad management, and all that...

Oh dear, that's bad news. Sounds like they are getting ready to re-signal the plant and at the very least make the operator's job 100% video games. Where does METRA have the money for that? Aren't they broke?

Jersey_Mike wrote:

EricL wrote:All of the crossovers are 10mph except for the 33 crossover, which is 25mph. Trains routed through that "fast" XO always receive a "Restricting" to enter the plant, but of course, they are permitted to increase speed once the head end takes something more favorable at the exit signal at the west end.

That's utterly ridiculous. How poor was the Milwaukee road that it couldn't install proper medium speed turnouts and appropriate signaling to support them?

As I mentioned earlier, the ones on the Elgin leg are legnth constrained by bridges. Plus in the old days, those were all one-directional tracks. There was probably little reason to have anyone crossing over there unless they were also using the other connectors.

But you want ridiculous, the TT (a recent CP as well as an old MILW one I have) lists a 40mph crossover at Itasca. It's a hand-throw!!! You're not using it except with dispatcher permission at restricted speed.

Jersey_Mike wrote:This is why I cannot stand western style route signaling because everything is so wishy washy. In that track 3 example with a 10mph turnout and a 15mph straight speed you don't need a R/R/G (as seen on eastern roads) because even tho the turnout is Slow Speed, it is the only diverging route so it could be signaled R/G/R. Eastbound Elgin tks 1 and 2 should get a R/G/R onto the C&M, but they could be signaled G/R/R because it is the only (non-Restricting) route so the speed restriction is handled in the timetable.

My railroading experience was with the pre-NS Norfolk & Western. We used route signalling. I find it more practical because you're not locked to certain speeds. There's also no need for a Medium signal where the fastest route is medium speed route.

My line had a lot of signaled sidings and DT-ST transitions. Into a siding or double-track, you could get a Diverging signal. But out of the siding or at end of DT where there was no route option, it was a normal-speed signal (Clear, etc.) even though you might only be allowed 25mph. No need for two heads where you couldn't take advantage of the extra aspects.

So as you say, Clear works coming off the Elgin since all it tells you is you're not diverging. It does rely on the engineer to know the railroad but unlike speed signalling, does allow you to adjust speed within interlocking limits as different speeds come into play (thankfully - the MD-W is slow enough as it is).

Jersey_Mike, you probably won't like what Metra has done WB at B-12. R/G/R and R/R/G are both Diverging Clear (and R/Y/R and R/R/Y are both Diverging Approach) but by TT SI, middle G or Y means you're lined for a 40mph route (crossovers west of the CN) and bottom G or Y means you're lined for a 25mph route (crossovers east of the CN and/or the NCS connection to the CN). It's de-facto speed signalling but not at standard speeds and without signals by that name.

Regarding searchlight signals, what do I know? My experience is with PRR-style position light signals. that's why I like those signals east of A-2. But at least on those, I know the difference between Diverging Approach and Restricting.

Real PRR position lights do not display Diverging Approach.

I assume you say that because on PRR, that was Medium Approach. But on my N&W, which used colorized PRR-style signals, is was Diverging Approach.

While I've never been able to put my hands on a copy of the Metra North Joint Tracks Special Instructions, I suspect Metra uses Diverging signals rather than Medium (if any of those remaining position light signals can even display Diverging aspects - the WB signals at A-2 get normal route signals today although I assume when the Panhandle was still there, moves to the Milwaukee got diverging or medium (or even slow) signals).

lstone19 wrote: But you want ridiculous, the TT (a recent CP as well as an old MILW one I have) lists a 40mph crossover at Itasca. It's a hand-throw!!! You're not using it except with dispatcher permission at restricted speed.

Think of it being used as a temporary block station (assuming ABS operation). Engineer gets orders from the TBS operator then hi-balls through the crossover at 40mph.

lstone19 wrote:My railroading experience was with the pre-NS Norfolk & Western. We used route signalling. I find it more practical because you're not locked to certain speeds. There's also no need for a Medium signal where the fastest route is medium speed route.

My line had a lot of signaled sidings and DT-ST transitions. Into a siding or double-track, you could get a Diverging signal. But out of the siding or at end of DT where there was no route option, it was a normal-speed signal (Clear, etc.) even though you might only be allowed 25mph. No need for two heads where you couldn't take advantage of the extra aspects.

Being locked to certain speeds simplifies operations dramatically and crews no longer need to memorize the quirky speeds of a hundred different turnouts. Medium speed signals to exit sidings require one additional red signal lamp or simply displaying one additional lamp on a G/Y/R dwarf stack.

lstone19 wrote:So as you say, Clear works coming off the Elgin since all it tells you is you're not diverging. It does rely on the engineer to know the railroad but unlike speed signalling, does allow you to adjust speed within interlocking limits as different speeds come into play (thankfully - the MD-W is slow enough as it is).

Being able to go a bit longer before braking or being able to increase speed a few seconds sooner doesn't really generate many benefits and are offset by the advantage of banishing oddball 10 and 25 and 35mph turnout speeds.

lstone19 wrote:Jersey_Mike, you probably won't like what Metra has done WB at B-12. R/G/R and R/R/G are both Diverging Clear (and R/Y/R and R/R/Y are both Diverging Approach) but by TT SI, middle G or Y means you're lined for a 40mph route (crossovers west of the CN) and bottom G or Y means you're lined for a 25mph route (crossovers east of the CN and/or the NCS connection to the CN). It's de-facto speed signalling but not at standard speeds and without signals by that name.

Oh I like it just fine because it shows that speed signaling is what is ultimately needed on real railroads with properly complex infrastructure. Route signaling is best on the single track and siding paradigm seen in the south and west in the early to mid 20th century...but in the 21st they would be best served by adopting speed signals and if you look at UP and BNSF signal rules both railroads have added new speed signaling indications.

Jersey_Mike wrote: Being able to go a bit longer before braking or being able to increase speed a few seconds sooner doesn't really generate many benefits and are offset by the advantage of banishing oddball 10 and 25 and 35mph turnout speeds.

First, from what I've seen, there are only three standard turnout speeds on the MD: 10, 25, and 40 although A-5 is an exception with the 15 for the curve including the junction switches at the east end. But is it really any different than having to remember all the oddball curve restrictions.

But I'll disagree about there not being many benefits to being able to change speed as you go through. For an outbound MD-W train, it's about 0.65 miles from the A-5 home signal to the A-5 exit signal. Traversing that distance takes 2:36 at 15mph and 3:54 at 10mph (and that's for a zero-length train; real times would be longer). It's 1/4 mile from the signal bridge to the junction turnouts / start of curve (it's so far east due to the 3-4 crossover that used to be there before 4 was pulled up), then 0.15 miles around the curve, and then another 1/4 mile for the west end of A-5 crossovers. By my calculations, the ability to keep the speed up right until the point of the restriction and accelerate as soon as clear saves me 1.5 minutes each way. For a daily commuter, that works out to about 12 hours per year.