Nov. 2023 Yellow Line Collision

[Busjack]

2 hours ago, Mr.NewFlyer1279 said:

gotta quote u on that one……the team is investigating everything

I was not talking about the NTSB. I was talking about Schakowsky and the other local politicians, as depicted on the 10:00 pm news.

[Mr.NewFlyer1279]

new info has been released…….take a few minutes to watch.

 

[Busjack]

25 minutes ago, Mr.NewFlyer1279 said:

new info has been released…….take a few minutes to watch.

 

For preliminary findings, this  was very instructive. Unlike what we thought, it was not a signal malfunction, the snowplow not tripping the signal, nor the operator not trying to stop, but that it would have taken 1,000 more feet to stop than the standard followed when the car was designed. Crud on the rails (my term) may have also resulted in slippage

NTSB will also study historical data on stopping time when a stopped train is in the prior block.

This also dispelled the impression given by TV that the tower radio message was directed to this operator, but it was to the following operator to stay at the Oakton station.

It also confirmed that of the 7 injured CTA employees, 6 were on the snow plow.

Thanks for finding this.

[Sam92]

50 minutes ago, Busjack said:

For preliminary findings, this  was very instructive. Unlike what we thought, it was not a signal malfunction, the snowplow not tripping the signal, nor the operator not trying to stop, but that it would have taken 1,000 more feet to stop than the standard followed when the car was designed. Crud on the rails (my term) may have also resulted in slippage

NTSB will also study historical data on stopping time when a stopped train is in the prior block.

This also dispelled the impression given by TV that the tower radio message was directed to this operator, but it was to the following operator to stay at the Oakton station.

It also confirmed that of the 7 injured CTA employees, 6 were on the snow plow.

Thanks for finding this.

When I watched it sounds like she said that that 1000 extra feet was not accounted for when the 5000s were ordered and thus the extra weight of the cars was not thought of when the stopping distance was designed. Does this mean that the signal blocks are most likely going to be readjusted? Sounds like even though the signal didn't malfunction it needs to be fine tuned and probably the whole system needs to be looked at seeing as a lot of signals were replaced just a bit before the 5000s arrived. 

[Bus1883]

16 minutes ago, Sam92 said:

When I watched it sounds like she said that that 1000 extra feet was not accounted for when the 5000s were ordered and thus the extra weight of the cars was not thought of when the stopping distance was designed. Does this mean that the signal blocks are most likely going to be readjusted? Sounds like even though the signal didn't malfunction it needs to be fine tuned and probably the whole system needs to be looked at seeing as a lot of signals were replaced just a bit before the 5000s arrived. 

The fact she says 1,780 ft is a design problem

[Busjack]

3 hours ago, Sam92 said:

Does this mean that the signal blocks are most likely going to be readjusted? Sounds like even though the signal didn't malfunction it needs to be fine tuned

On this I agree. Either the block has to be moved from about Custer/Damen to around Ridge Ave., or the speed limit approaching that stretch has to be cut from (as I heard it) 69 mph. Sort of similar to the O'Hare accident where the finding was to cut the speed limit from 25 mph to 20.

if the brakes engaged at 1700 ft (1/3 mile), the car was still doing 39 mph at impact, which under either of my theories, is too much.

[strictures]

10 hours ago, Busjack said:

the speed limit approaching that stretch has to be cut from (as I heard it) 69 mph.

I thought there was a system wide speed limit of 55.

[artthouwill]

10 hours ago, Busjack said:

On this I agree. Either the block has to be moved from about Custer/Damen to around Ridge Ave., or the speed limit approaching that stretch has to be cut from (as I heard it) 69 mph. Sort of similar to the O'Hare accident where the finding was to cut the speed limit from 25 mph to 20.

if the brakes engaged at 1700 ft (1/3 mile), the car was still doing 39 mph at impact, which under either of my theories, is too much.

NTSB  confirmed in the presser that CTA trains are governed to a max speed of 58 mph.  I've personally heard the cab warning when the operator reached that speed.   The supposed speed limit is 55 mph maximum,  but obviously is lower in many areas. 

NTSB said the event recorder recorded a speed of 26.9 mph at impact.  What is unclear is when the operator started braking and how much braking he applied.   Apparently stopping distances were calculated on an older model car.  Are those based on 2400/2600/3200 series, 2000/2200s, or 6000s,?  What about the current 7000s?   CTA certainly will have to address this with the 9000 series cars.

[Busjack]

2 hours ago, strictures said:

I thought there was a system wide speed limit of 55.

 

2 hours ago, artthouwill said:

NTSB  confirmed in the presser that CTA trains are governed to a max speed of 58 mph.  I've personally heard the cab warning when the operator reached that speed.   The supposed speed limit is 55 mph maximum,  but obviously is lower in many areas. 

NTSB said the event recorder recorded a speed of 26.9 mph at impact.  What is unclear is when the operator started braking and how much braking he applied.   Apparently stopping distances were calculated on an older model car.  Are those based on 2400/2600/3200 series, 2000/2200s, or 6000s,?  What about the current 7000s?   CTA certainly will have to address this with the 9000 series cars.

1. If I misheard by 10 mph each, so be it.  Sun-Times article says I misheard the impact speed.
2. On @artthouwill's second point, the PCC design was discarded at least with the 2000s, which had 100 hp motors instead of the PCC 55 hp motors. The literature said that those and the later compatible series were capable of 70 mph but were limited by the signal system to 55 mph. But to get to the relevant issue, chicago-l.org says that the original RFP was for a 3500 series compatible with the 3200s, but that was canceled to change from DC to AC. (The word at the time was that manufacturers would not bid on an obsolete spec.) Similarly, the first 7000 spec. was pulled because CTA couldn't get competitive bids on a spec. compatible with the 5000s.
3. The weight issue came up before when it was asked why 5000s couldn't run on the Forest Park segment, but 7000s can. Now it has arisen in this context.

15 hours ago, Bus1883 said:

The fact she says 1,780 ft is a design problem

That was obvious. @Sam92's comment was directed at what to do about it

[Sam92]

3 hours ago, artthouwill said:

NTSB  confirmed in the presser that CTA trains are governed to a max speed of 58 mph.  I've personally heard the cab warning when the operator reached that speed.   The supposed speed limit is 55 mph maximum,  but obviously is lower in many areas. 

NTSB said the event recorder recorded a speed of 26.9 mph at impact.  What is unclear is when the operator started braking and how much braking he applied.   Apparently stopping distances were calculated on an older model car.  Are those based on 2400/2600/3200 series, 2000/2200s, or 6000s,?  What about the current 7000s?   CTA certainly will have to address this with the 9000 series cars.

Well one thing that I'll note is that once "putting the rapid back in transit" became a thing, I seem to remember other projects outside of whatever major trackwork involving signal updates (Dearborn subway, NSM, a more vibrant red) a lot of stuff occuring when 2200-3200s were out. What's concerning is that now 5000s are pretty much the workhorse and run 5 out of lines so there's a lot of adjustments to be made with these being  one of the heaviest models. Also because of location of incident they might look closer at areas with limited visibility considering the train looked to be coming from out the trench and beginning to negotiate through the yard into Howard. 26mph still seems a bit much and maybe that should be a 15mph zone. I don't remember rising 30mph through that stretch the rare times I took a ride on the swift but again Its been a while 

[Busjack]

On 11/19/2023 at 12:22 PM, Sam92 said:

Also because of location of incident they might look closer at areas with limited visibility considering the train looked to be coming from out the trench and beginning to negotiate through the yard into Howard. 26mph still seems a bit much and maybe that should be a 15mph zone.

1780 feet is 1/3 mile, so, as I indicated, if the brakes came on as indicated, that would have been around Custer Ave., so there's no way one could have seen any obstruction at Chicago Ave. at that point.

Also, the impact speed was 26.9 mph. That obviously wasn't the speed when entering the rolling block 1/3 mile earlier.

As I indicated, adjusting the speed limit may be an answer, but the first step would seem to be that if this is a "design issue," the engineers need to figure out the maximum safe* braking rate for 5000s. They also need to determine what other stretches of track allow the trains to get to speed, This might include the Red Line from 79th to 69th, for instance.

_______________

*By safe, I mean considering the effects of sudden deceleration on the passengers, either from braking or collision.

[Nitro]

On 11/18/2023 at 2:11 PM, strictures said:

I don't know why any of those things weren't done, but I do know one thing from waiting for trains for decades at Howard:  The Howard Tower operators seem to run a different rail road than the rest of the CTA!  I can't tell you how many times they load up both tracks 1 & 2 with SB trains to 95th, which prevents both Skokie & Evanston trains from going through the station after dropping off their passengers on the SB platform, so they can get to the turn back track to go back north. 

And lately they also been clogging up both NB tracks with Howard trains, because apparently one has a motorman that's now off duty, but then there's no one to take the train into the yard or no new motorman to take it into the loop track to return south. 

We can thank the fact that it was an at grade structure. Due to safety hazards and the obvious so subtle NIMBYs that don’t want at grade structures in their neighborhood because they believe it would increase hazards on "the road".

[Nitro]

On 11/19/2023 at 2:56 PM, Busjack said:

1780 feet is 1/3 mile, so, as I indicated, if the brakes came on as indicated, that would have been around Custer Ave., so there's no way one could have seen any obstruction at Chicago Ave. at that point.

Also, the impact speed was 26.9 mph. That obviously wasn't the speed when entering the rolling block 1/3 mile earlier.

As I indicated, adjusting the speed limit may be an answer, but the first step would seem to be that if this is a "design issue," the engineers need to figure out the maximum safe* braking rate for 5000s. They also need to determine what other stretches of track allow the trains to get to speed, This might include the Red Line from 79th to 69th, for instance.

_______________

*By safe, I mean considering the effects of sudden deceleration on the passengers, either from braking or collision.

There you go, CBTC/ATO is the only way to "fix this issue". If the CTA is going to increase public safety and due to the pressure from NIMBYs and "other transit advocates". The Yellow Line will have to be fully elevated and grade separated from "L" crossings to accommodate the solution. You just gave yourself the answer. 

[Busjack]

3 hours ago, Nitro said:

There you go, CBTC/ATO is the only way to "fix this issue". If the CTA is going to increase public safety and due to the pressure from NIMBYs and "other transit advocates". The Yellow Line will have to be fully elevated and grade separated from "L" crossings to accommodate the solution. You just gave yourself the answer. 

No, you're the one who went in your pants. CBTC is more primitive than what CTA already has.  CBTC isn't ATO. I read the CBTC page, you didn't. Among other things, it said CBTC will not be installed on work trains. The Yellow Line train hit a work car that had ATC. The ATC worked as expected. The NTSB (not you), preliminarily found that something was not properly programmed to calculate the actual stopping distance.

As for the actual experts in Chicago (here's another link you won't read), Joseph Schwieterman, the director of the Chaddick Institute for Metropolitan Development at DePaul University, said:

‘Positive train control’ as a possible solution

“PTC is a system of interconnected wireless devices that can automatically break {sic] a train when it sees the trains in harm’s way,” Schwieterman said.

Other agencies have adopted the system, which Schwieterman said is “much more sophisticated” than the GPS-based systems. {Actually, neither ATC nor CBTC is GPS based].

“It’s really mandated by Congress after a terrible accident on Amtrak a number of years ago,” Schwieterman said. “And most of the freight railroads and Metra now have PTC, but it’s proven a bridge too far for some of the rail transit agencies.”

The reason PTC isn't required for rapid transit is that that mode of transportation is not regulated by the FRA. As an expert on the FRA, you should have known that. MTA IS NOT INSTALLING PTC IN THE SUBWAY.

Your idiocy about the Yellow Line (at that point it is in a trench; it didn't hit a car at East Prairie Road) shows your hypocrisy. You didn't pick up my hints about the Interborough Express; let me make it explicit:

The plan calls for an LRV on a freight track. It's not grade separated and nothing indicates that it would have PTC.

I have given you enough to contemplate, but, if you have any shame at all, please don't bother us with your so-called NY "superiority" again.

[Nitro]

7 minutes ago, Busjack said:

No, you're the one who went in your pants. CBTC is more primitive than what CTA already has.  CBTC isn't ATO. I read the CBTC page, you didn't. Among other things, it said CBTC will not be installed on work trains. The Yellow Line train hit a work car that had ATC. The ATC worked as expected. The NTSC (not you), preliminarily found that something was not properly programmed to calculate the actual stopping distance.

As for the actual experts in Chicago (here's another link you won't read), Joseph Schwieterman, the director of the Chaddick Institute for Metropolitan Development at DePaul University, said:

‘Positive train control’ as a possible solution

“PTC is a system of interconnected wireless devices that can automatically break {sic] a train when it sees the trains in harm’s way,” Schwieterman said.

Other agencies have adopted the system, which Schwieterman said is “much more sophisticated” than the GPS-based systems. {Actually, neither ATC nor CBTC is GPS based].

“It’s really mandated by Congress after a terrible accident on Amtrak a number of years ago,” Schwieterman said. “And most of the freight railroads and Metra now have PTC, but it’s proven a bridge too far for some of the rail transit agencies.”

The reason PTC isn't required for rapid transit is that that mode of transportation is not regulated by the FRA. As an expert on the FRA, you should have known that. MTA IS NOT INSTALLING PTC IN THE SUBWAY.

Your idiocy aboiut the Yellow Line (at that point it is in a trench; it didn't hit a car at East Prairie Road) shows your hypocrisy. You didn't pick up my hints about the Peterborough Express; let me make it explicit:

The plan calls for an LRV on a freight track. It's not grade separated and nothing indicates that it would have PTC.

I have given you enough to contemplate, but, if you have any shame at all, please don't bother us with your so-called NY "superiority" again.

Do you think the CTA is governed by the FRA? If you believe that you are delusional. It's absurd that any transit infrastructure aside from railroads would ever have railroad technology installed on their lines, That is with the exemption of PATH. Rapid transit doesn’t fall under the categories of the FRA at all. Light Rail is restricted because it isn't compliant with FRA regulations and has to be grade separated from freight rail. The Interborough Tortoise, that shit has fail all over it and would be infrequent compared to buses. Also stop bringing up New York, It makes you sound misinformed.

[Busjack]

1 hour ago, Nitro said:

It's absurd that any transit infrastructure aside from railroads would ever have railroad technology installed on their lines

Tell that to Professor Schweiterman and to the NTSB, not me. I was only quoting him.

Quote

The Interborough Tortoise, that shit has fail all over it....

As I  indicated before, it was to show your hypocrisy, especially when you said a signal system that is inferior to what CTA already has is coming to CTA.

Quote

 Also stop bringing up New York, It makes you sound misinformed.

LOOK WHO'S TALKING (the title of a Kirstie Alley and John Travolta film about a baby). Someone who just admitted that his knowledge of Chicago is based on a virtual tour of Google Maps is calling someone else misinformed? Doctor, heal thyself. Take your own advice and stop posting about Chicago.

[andrethebusman99]

The CTA cab signal system has been in use starting in 1969 and system wide since 1975. Many would say it actually made the system less safe because prior to that, the motorman was responsible for keeping his eyes open. Afterwards, he started depending on the cab signal to tell him what was going on in front of him. The wrecks since then have all been basically because of humans over depending on technology. Wabash/Lake was not looking in front of you but down in the street. Addison was not adapting. If you can't see in front of you, slow down until you can stop within half the distance you can see ahead. O'Hare was literally asleep at the controls. All human failures, not technology failures. You can make technology fail-safe, you can't make it fool-proof.

[Busjack]

59 minutes ago, andrethebusman99 said:

Many would say it actually made the system less safe because prior to that, the motorman was responsible for keeping his eyes open.

I don't know about that. Having looked at chicago-l.org mishaps page and other incidents page either informed me or refreshed by recollection that rear ending and overspeeding were frequent:

• Granville 1936: North Shore train splintered a wooden L train
• Wilson 1956: L train rammed a North Shore train
• Englewood: Train went into a building
• 40th 1962: Derailment, 2 killed
• 40th 1969: rearending*
• 40th 1972: train fell off structure
• South Blvd 1973: Evanston train hit another
• Skokie 1973: Train overshot the switch at the end of the line
• 35th 1974: Plowed into stopped train
• Tower 18 1974: Ravenswood train misses turn
• 29th St 1974: Rearending

I think after that CTA was firmly in the ATC era, but accidents were frequent in 1973-1974. As I noted above, the accidents after 1974 had multiple concurrent causes, but the ATC logic didn't prevent the accidents, and operator inattention was certainly a cause. Other than the Lake-Wabash one, no one appears to have been killed.

________________

*I remember, and GG confirms, that this was the most famous one where bystanders climbed the structure to "buy a lawsuit."

 

[Sam92]

On 11/19/2023 at 1:56 PM, Busjack said:

1780 feet is 1/3 mile, so, as I indicated, if the brakes came on as indicated, that would have been around Custer Ave., so there's no way one could have seen any obstruction at Chicago Ave. at that point.

Also, the impact speed was 26.9 mph. That obviously wasn't the speed when entering the rolling block 1/3 mile earlier.

As I indicated, adjusting the speed limit may be an answer, but the first step would seem to be that if this is a "design issue," the engineers need to figure out the maximum safe* braking rate for 5000s. They also need to determine what other stretches of track allow the trains to get to speed, This might include the Red Line from 79th to 69th, for instance.

_______________

*By safe, I mean considering the effects of sudden deceleration on the passengers, either from braking or collision.

 

On 11/18/2023 at 10:24 PM, Busjack said:

On this I agree. Either the block has to be moved from about Custer/Damen to around Ridge Ave., or the speed limit approaching that stretch has to be cut from (as I heard it) 69 mph. Sort of similar to the O'Hare accident where the finding was to cut the speed limit from 25 mph to 20.

if the brakes engaged at 1700 ft (1/3 mile), the car was still doing 39 mph at impact, which under either of my theories, is too much.

All trolling aside; Was on an L group earlier.... The concensus among operators is that the trains themselves can stop within a city block or two even the 5000s.... From what I'm reading, the signal blocks themselves indeed need to be spaced 2700 ft apart in that speed zone in order to give enough of a warning for the speeds in that block. Lower allowable speeds would allow for shorter blocks. So I guess a lot of signal work and adjustments are gonna be made as guessed earlier to handle the issue; nothing necessarily needed to be done to any cars themselves. ?

[Busjack]

6 hours ago, Sam92 said:

 

All trolling aside; Was on an L group earlier.... The concensus among operators is that the trains themselves can stop within a city block or two even the 5000s.... From what I'm reading, the signal blocks themselves indeed need to be spaced 2700 ft apart in that speed zone in order to give enough of a warning for the speeds in that block. Lower allowable speeds would allow for shorter blocks. So I guess a lot of signal work and adjustments are gonna be made as guessed earlier to handle the issue; nothing necessarily needed to be done to any cars themselves. ?

Your mention of "stop within a city block" reminds me that the cars have regenerative, disc, and magnetic track brakes, and an emergency position. The passenger's comment that the brakes didn't engage until too late may have referred to the emergency application. Anyway, as expected, the preliminary determination may be too preliminary.

[Rhys Pate]

Yellow Line Shuttle bus operations: the buses are operated by North Park (P) and Forest Glen (F) Garages. Yellow Line Shuttle buses operate westbound via Howard Station, Howard, Skokie, Dempster, and Dempster/Skokie Station. Yellow Line Shuttle buses operate eastbound via Dempster/Skokie Station, Dempster, Skokie, Howard, Clark, Rogers, and Howard Station. The westbound Yellow Line Shuttle stop for Oakton/Skokie Station is the 54A stop at Skokie/Searle. The eastbound Yellow Line Shuttle stop for Oakton/Skokie Station is at the 54A Oakton Yellow Line Station stop (on Skokie between Searle and Keeney).

[Rhys Pate]

Buses 8251 and 8232 on the Yellow Line Shuttle yesterday (November 24th, 2023). 8251 is photographed at Dempster/Skokie Station and 8232 is photographed at Howard Station.

[Bus1883]

6 hours ago, Rhys Pate said:

Buses 8251 and 8232 on the Yellow Line Shuttle yesterday (November 24th, 2023). 8251 is photographed at Dempster/Skokie Station and 8232 is photographed at Howard Station.

The NTSB still investigating the crash? Wow 

[Busjack]

1 hour ago, Bus1883 said:

The NTSB still investigating the crash? Wow 

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.

[Rhys Pate]

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