Nov. 2023 Yellow Line Collision

[Bus1883]

On 11/25/2023 at 3:28 PM, Busjack said:

They said it would take 12-18 months. It always does.

But I couldn't see from Chicago Ave. whether the tracks have been cleared. The shuttle buses are still running.

I forgot about the timeline. I meant until the line reopens thanks tho?

[Busjack]

23 minutes ago, Bus1883 said:

I forgot about the timeline. I meant until the line reopens thanks tho?

Sun-Times essentially says no news.

[Rhys Pate]

What is more likely: that 5599 will be repaired and return to service at a later time, or that 5599 will be retired?

Are the 5000-Series cars compatible with the 7000-Series cars?

If 5599 ends up being retired and the answer to the compatibility question is yes, could the CTA order 1 extra 7000-Series car to pair with 5600? This is what the CTA did to make the 2600-Series/3200-Series mismate pair 3457-3458. 3458 was originally numbered 3032. 3031, 3458’s original mate, was irreparably damaged when it hit the Wilson station platform in 1988 due to splitting a switch. 3032 was still a useable car, despite 3031 being totaled. A few years later, in 1994, 3032 returned to service after being paired with an extra 3200-Series car (3457) and being renumbered 3458.

[Busjack]

1 hour ago, Rhys Pate said:

What is more likely: that 5599 will be repaired and return to service at a later time, or that 5599 will be retired?

Are the 5000-Series cars compatible with the 7000-Series cars?

If 5599 ends up being retired and the answer to the compatibility question is yes, could the CTA order 1 extra 7000-Series car to pair with 5600? This is what the CTA did to make the 2600-Series/3200-Series mismate pair 3457-3458. 3458 was originally numbered 3032. 3031, 3458’s original mate, was irreparably damaged when it hit the Wilson station platform in 1988 due to splitting a switch. 3032 was still a useable car, despite 3031 being totaled. A few years later, in 1994, 3032 returned to service after being paired with an extra 3200-Series car (3457) and being renumbered 3458.

• Since it appears that the framing behind the end cap was crushed, retirement is most likely.
• Most likely, 5000s and 7000s are not compatible. You're thinking about 3457 being paired with 3032, which became 3458, but
  • 2600s and 3200s were compatible.
  • At the time 3257 was purchased there was still an active car order in progress. There isn't an active car order for 5000s. Bombardier Transit is out of business, and although it was purchased by Alstom, Alstom isn't interested in building one custom car.

[artthouwill]

1 hour ago, Rhys Pate said:

What is more likely: that 5599 will be repaired and return to service at a later time, or that 5599 will be retired?

Are the 5000-Series cars compatible with the 7000-Series cars?

If 5599 ends up being retired and the answer to the compatibility question is yes, could the CTA order 1 extra 7000-Series car to pair with 5600? This is what the CTA did to make the 2600-Series/3200-Series mismate pair 3457-3458. 3458 was originally numbered 3032. 3031, 3458’s original mate, was irreparably damaged when it hit the Wilson station platform in 1988 due to splitting a switch. 3032 was still a useable car, despite 3031 being totaled. A few years later, in 1994, 3032 returned to service after being paired with an extra 3200-Series car (3457) and being renumbered 3458.

The 5000s are NOT compatible with the 7000s.  If 5599  isn't repaired,  5600 will remain unmated until another 5500 series car loses its mate, then those two cars will be mated.  They will not be renumbered.  I believe the only reason 3032 was renumbered was because of the difference between 3032 and 3457.  While the two series were compatible,  3457 uses the Coniston to operate the train as opposed to the stick used on 3032.  Therefore by numbering it with a 3200 series car, it w would ensure that the operator was a qualified 3200 series operator.  During that time, I don't think all operators were qualified to operate 3200 series cars, especially out of Howard Yard.

[Busjack]

Another issue with "pairing with 5600" is that we don't know if or what damage 5600 sustained from the impact.

The reason I bring this up is that in the Forest Park and O'Hare accidents, the entire trains were retired, although it could have been argued that the one that rolled out of the Forest Park yard should have been retired before then.

[andrethebusman99]

Given the "abundance of caution" fetish these days, expect Yellow to be out of service for weeks if not months until the signal blocks are rewired. This is not like an earlier era when wreck was removed and service resumed the same or next day like Addison, Lake/Wabash, Harlem/Congress, etc. Now, "what if something happens again?" is so feared that common sense and revised operating practices if necessary no longer matter. No level of risk is acceptable.

[andrethebusman99]

7 hours ago, Rhys Pate said:

What is more likely: that 5599 will be repaired and return to service at a later time, or that 5599 will be retired?

Are the 5000-Series cars compatible with the 7000-Series cars?

If 5599 ends up being retired and the answer to the compatibility question is yes, could the CTA order 1 extra 7000-Series car to pair with 5600? This is what the CTA did to make the 2600-Series/3200-Series mismate pair 3457-3458. 3458 was originally numbered 3032. 3031, 3458’s original mate, was irreparably damaged when it hit the Wilson station platform in 1988 due to splitting a switch. 3032 was still a useable car, despite 3031 being totaled. A few years later, in 1994, 3032 returned to service after being paired with an extra 3200-Series car (3457) and being renumbered 3458.

Any time stainless steel is involved, even minor damage is almost always fatal. Stainless steel is just too difficult to work with.

[Busjack]

1 hour ago, andrethebusman99 said:

Given the "abundance of caution" fetish these days, expect Yellow to be out of service for weeks if not months until the signal blocks are rewired. This is not like an earlier era when wreck was removed and service resumed the same or next day like Addison, Lake/Wabash, Harlem/Congress, etc. Now, "what if something happens again?" is so feared that common sense and revised operating practices if necessary no longer matter. No level of risk is acceptable.

it's probably now "reprogram" rather than "rewire," but I agree that the days of trains repeatedly rear-ending other trains on the SSM are over.

The official NTSB investigation site for this accident is here.

[andrethebusman99]

1 hour ago, Busjack said:

it's probably now "reprogram" rather than "rewire," but I agree that the days of trains repeatedly rear-ending other trains on the SSM are over.

The official NTSB investigation site for this accident is here.

What would need doing is add a red block in front of the existing occupied red block. Should not be that hard to do. I remember in 1990s number of reds behind a train in State Subway was increased to as many as four in station areas, and this with 1940s signal equipment.

[Busjack]

1 hour ago, andrethebusman99 said:

What would need doing is add a red block in front of the existing occupied red block. Should not be that hard to do. I remember in 1990s number of reds behind a train in State Subway was increased to as many as four in station areas, and this with 1940s signal equipment.

But since ATC was put in, the blocks are floating. Hence, while I previously indicated before that solutions may be either reducing the speed limit or lengthening the blocks, it isn't by rewiring 1940s technology. This ain't MTA, and I assume chicago-l.org"s description of ATC still applies, else there is this Google search..

[artthouwill]

On 11/26/2023 at 8:36 PM, Bus1883 said:

I forgot about the timeline. I meant until the line reopens thanks tho?

First, there has to be room to store the damaged equipment at Skokie Shops.  Then the crash site has to be cleared.  The tracks have to be inspected for damage and repaired if necessary.  The tracks may also have to be cleared of whatever debris that was on the tracks that caused the wheels of the crash train to slip. Signals and speed limits will have to be readjusted.   More than likely CTA will want to run test trains to ensure everything is in order before opening the Yellow Line for service. 

[Busjack]

CTA Press Release on status of resuming service, but nothing new.

[TGranzow29]

On 11/25/2023 at 5:01 PM, Rhys Pate said:

No date has been set for Yellow Line train service to resume. Yellow Line train service is suspended indefinitely.

Do we have a particular reason why? I figured that after the accident, with the train and the slow plow being cleared off of the tracks, service would be able to resume. There must be something deeper here that we don't know about.

[Busjack]

2 hours ago, TGranzow29 said:

Do we have a particular reason why? I figured that after the accident, with the train and the slow plow being cleared off of the tracks, service would be able to resume. There must be something deeper here that we don't know about.

If you had read the CTA Press Release cited a couple of posts above, you would have the official answer.

[TGranzow29]

58 minutes ago, Busjack said:

If you had read the CTA Press Release cited a couple of posts above, you would have the official answer.

I wasn't seeing anything on the CTA website when I was looking for information and I didn't see the post above so that's why I asked. Thanks.

[Busjack]

News reports that NTSB has issued its preliminary findings, which are here. The description of the brake and signal systems are as I stated.

The relevant findings are:

The operator was aware that the snow removal machine was operating on the Yellow Line as part of a training exercise but did not know its exact location. Shortly before the collision, the southbound snow removal machine stopped about 370 feet north of a red signal indication.[6] The passenger train was traveling southbound about 54 mph when the operator received a stop command from the signal system because of the snow removal machine stopped on the track about 2,150 feet ahead. The operator immediately initiated a full service braking application to stop the train.[7] The operator then saw the snow removal machine and initiated an emergency braking application.[8] The train decelerated to about 27 mph before striking the snow removal machine. Preliminary review of the train’s event recorder showed that the wheel slide protection system activated throughout both braking applications. (emphasis added by me)

...

The NTSB’s investigation is ongoing. Future investigative activity will focus on the design and configuration of the CTA signal system, the design and braking performance of the railcars involved in the accident, and examination of organic material present on top of the running rails investigators collected to determine what impact, if any, this material had on the accident. 

But it apparently isn't operator error, the snow removal machine not tripping the signal system, or (I'll leave out the epithets) CTA not having a cab signal system and control center.

One bit of news to me is:

[7] On 5000-series railcars, a full service braking application uses only the dynamic brakes until the train has decelerated to about 5 mph, then engages the friction brakes.

[strictures]

5 hours ago, Busjack said:

[7] On 5000-series railcars, a full service braking application uses only the dynamic brakes until the train has decelerated to about 5 mph, then engages the friction brakes.

I seem remember from a CERA book that I read years ago said the friction brakes on the 6000s didn't engage until 1 MPH!

[dailycommuter62]

I was under the impression if a upcoming block was occupied (passing a yellow signal) the cab signal would of ordered a 35 mph speed limit but here the train was allowed to go max 55 mph into a red signal. Also if it hit the snowblower at 27 mph based on the location it hit it its just 2-300 feet from the interlocking, makes it sound like the snowblower being positioned there was a bizarre coincidence that stopped the train barreling into the junction.

[Busjack]

3 hours ago, dailycommuter62 said:

makes it sound like the snowblower being positioned there was a bizarre coincidence that stopped the train barreling into the junction.

I'm trying to make out the sentence  "Shortly before the collision, the southbound snow removal machine stopped about 370 feet north of a red signal indication." It sounds like the snowblower stopped short of the junction with the Howard Yard, and then 5599 got a red 2150 feet (4/10 mile) further back. But that's just inference.

I don't know if the system is still the original 55/35/15 pattern, but slamming into the snowplow at 27 mph after being under red or braking for 4/10 of a mile does sound strange.

 

[Sam92]

9 hours ago, Busjack said:

I'm trying to make out the sentence  "Shortly before the collision, the southbound snow removal machine stopped about 370 feet north of a red signal indication." It sounds like the snowblower stopped short of the junction with the Howard Yard, and then 5599 got a red 2150 feet (4/10 mile) further back. But that's just inference.

I don't know if the system is still the original 55/35/15 pattern, but slamming into the snowplow at 27 mph after being under red or braking for 4/10 of a mile does sound strange.

 

Happened to run across it on Facebook before coming here. Looks like an experienced motorman and he states that as you said it should have progressed down in speed the way you described. Also hypothesizes that part of the reason might be that the snow plow didn't trigger the ATC so if non revenue equipment can't register on the ATC without being attached to a revenue train then maybe there should have been a flagger in the area. Also the blind spot doesn't help IMO

[dailycommuter62]

The brief also mentioned organic material (likely leaves) present on the tracks that could affect braking performance. From the yellow line ride along under normal running a train gets slowed down to walking pace at the point the collision happened. Sounds like a combination of a few things contributing to the crash.

[Busjack]

1 hour ago, Sam92 said:

Also hypothesizes that part of the reason might be that the snow plow didn't trigger the ATC so if non revenue equipment can't register on the ATC without being attached to a revenue train

The post starts with "I have reservations about" the preliminary finding about the signals. Fair enough, but the NTSB had the event recorder and other data, and said that 5599 was braking for 2150 feet. While we've said something doesn't add up if 5599 still hit S500 at 27 mph, I don't think the NTSB is lying, and any flagger would have had been at Asbury Ave. and moving a 1/2 mile behind S500 to have averted the crash under his theory.

[Sam92]

1 hour ago, dailycommuter62 said:

The brief also mentioned organic material (likely leaves) present on the tracks that could affect braking performance. From the yellow line ride along under normal running a train gets slowed down to walking pace at the point the collision happened. Sounds like a combination of a few things contributing to the crash.

I knew I wasn't imagining things when I figured 27mph seemed high for that spot. That's basically the throat into the yard right? Shouldn't there be a switch or set of them not too far behind that point to where it should have been at max 15 mph? 

 

26 minutes ago, Busjack said:

The post starts with "I have reservations about" the preliminary finding about the signals. Fair enough, but the NTSB had the event recorder and other data, and said that 5599 was braking for 2150 feet. While we've said something doesn't add up if 5599 still hit S500 at 27 mph, I don't think the NTSB is lying, and any flagger would have had been at Asbury Ave. and moving a 1/2 mile behind S500 to have averted the crash under his theory.

That still leaves the question of was the plow itself alone supposed to be enough to trigger the ATC/slower speed by showing that it's occupying that block? That's how it's supposed to work as far as your earlier reference to ATC being "floating blocks" right? I know the wayside signals are supposed to show a red or yellow proceed with caution aspect but preliminary reports didn't mention much about the wayside signals in the area if there are any and that along with @dailycommuter62's mention of the usual walking speeds observed In that area falls under the parts that aren't adding up. 

[Busjack]

3 hours ago, Sam92 said:

but preliminary reports didn't mention much about the wayside signals in the area if there are any and that along with @dailycommuter62's mention of the usual walking speeds observed In that area falls under the parts that aren't adding up. 

As I mentioned to our New Yawker, the last wayside block signals were removed by CTA in about 1998 (were in the Milwaukee-Dearborn subway) and everything is under ATC cab signals.

What else that doesn't add up to me was that the prior description of red was an enforced stop and then 15 mph, not head through at 15 mph (which this train wasn't doing if the impact was at 27 mph). Your correspondent mentioned something about ATC Bypass, which might enter into it, but he said there was no evidence of running on Bypass.