Charlotte's Light Rail: Lynx Blue Line

[skymiler]

PTC was federally mandated.  That should be The first clue that it's not cost effective.  The Class 1 railroads knew of this technology years before the mandate.  The cost to develop, install, train and implement did not justify the means.  Additionally PTC is a safety overlap system that helps prevent human error.  It is not an autonomous system, meaning that you still need a human to operate the train.  There are autonomous systems out there, however our federal government is doing it's best to regulate/mandate trains have at least one person/employee on them.

[DEnd]

Just now, skymiler said:

 There are autonomous systems out there, however our federal government is doing it's best to regulate/mandate trains have at least one person/employee on them.

There is also the cost issue.  Autonomous train systems cost much more to build than non-automated ones.  There are a lot of sunk cost that translate into it being cheaper to run the trains with operators and ticket checkers vs. fully autonomous in most light rail systems.  In Places where subways or elevated systems are justified autonomous systems are likely justified as well, as they can cost effectively increase service.  But considering the high cost of construction in the US that would likely be one of the first things cut in an effort to save money as well.

[kermit]

10 hours ago, elrodvt said:

Makes perfect sense but does it cost more? You know how that goes...

Yeah, capital costs are high. You gotta install platform doors (among other things) but once the system is working there is very little additional cost to increasing the frequency of operations.

Having said that, I don't think it would be a necessary or usefull improvement for CATS at this point. But if transit in Charlotte ever gets dense enough to require substantial operational changes to make it work I would think going from manual operations directly to fully automated (skipping PTC) would make the most sense.

Edited July 12, 2017 by kermit

[LKN704]

^Technically you don't need platform screen doors. 

Vancouver's Skytrain and London's DLR don't have platform screen doors. 

I believe however Honolulu's new automated metro system will be the first system in the US to have platform screen doors when it opens in the coming years. 

[kermit]

^ can't speak to Vancouver but the DLR does have a 'driver' (they don't really drive) onboard each train who monitors closing doors to verify that no one is trapped. Thus it's only kinda automated.

[ajfunder]

On 7/11/2017 at 7:11 PM, elrodvt said:

With all the talk about PTC for Amtrak does anyone know if the blue line has or is capable of having PTC? Without that I would think overlap brings some safety issues or greatly reduces frequency of operations.

The LYNX line (like most light rail lines in the US) does not require PTC under federal guidelines (and will not) because it already has an operator error technology in place called Automatic Train Protection (ATP). ATP has the same capabilities as PTC such as automatically stopping a train that is going over the speed limit or runs a red signal. 

[elrodvt]

^Cool. Does that mean overlapping could fit in then without too much impact on either lines max throughput? In other words does ATP allow them to come closer to each other than without ATP? Seems like such a simple thing until you start thinking of the details. Must be some interesting simulation software out there.

[ajfunder]

7 hours ago, elrodvt said:

^Cool. Does that mean overlapping could fit in then without too much impact on either lines max throughput? In other words does ATP allow them to come closer to each other than without ATP? Seems like such a simple thing until you start thinking of the details. Must be some interesting simulation software out there.

Indeed it is complex, just ask Denver and there struggle to get the crossing gate PTC software on the A, B, and G commuter lines to function properly. It took them nearly a year and a half to remedy the issue.

 

in regards to sharing, ATP would allow for overlapping but there are other factors that would have to be considered as well. The OCS system just had to be upgraded to allow for three car trains, and I would bet that higher frequencies would require even further upgrades in the overlapping segment. Also, higher frequencies would also mean more disruption at Uptown crossings.

[southslider]

Somehow Dallas was able to survive all this time with all their lines converging downtown on what is the largest light rail system in the US. Granted, they continue to aspire for a second "DT2" line, but their existing spine functions, and virtually all at grade.

[kermit]

Also keep in mind the Victoria line in London manages to run 2 minute frequencies all day long without any special hardware or software beyond what CATS already has installed. 

[AP3]

9th Street station progress



Sent from my iPhone using Tapatalk

[archiham04]

On 7/13/2017 at 7:17 PM, kermit said:

Also keep in mind the Victoria line in London manages to run 2 minute frequencies all day long without any special hardware or software beyond what CATS already has installed. 

Okay, so I guess I'm just now understanding that overlapping is a scheduling problem.  I just assumed that since trains and train tracks had been around for , oh I don't know 150 years... and that "switching" had been figured out.  I am dumbfounded.

Edited July 17, 2017 by archiham04

[Nick2]

Don't do yoga on the tracks folks.

[KJHburg]

Incompetent management and coverups like this really damage the chances of any future expansion of the LYNX lines. WSOCTV is reporting 12% of the concrete ties were cracked or damaged on the extension and this is the cause of the delay. They had to get the emails through Freedom of Information act to discover this after a tip. They just showed this on the 6 pm news and I will link the report when they update their website. 

[Matthew.Brendan]

[QClifer]

What did you expect from a govt project? They have plenty of money. No worries

[kermit]

1 minute ago, QClifer said:

What did you expect from a govt project? They have plenty of money. No worries

if the story is accurate then the cost is on the contractor (I would hope that CATS wrote delay penalties into the construction contracts)

[KJHburg]

Here is the video link from WSOC TV http://www.wsoctv.com/video?videoId=565428541&videoVersion=1.0

[kermit]

18 hours ago, KJHburg said:

Incompetent management and coverups like this really damage the chances of any future expansion of the LYNX lines. WSOCTV is reporting 12% of the concrete ties were cracked or damaged on the extension and this is the cause of the delay. They had to get the emails through Freedom of Information act to discover this after a tip. They just showed this on the 6 pm news and I will link the report when they update their website. 

Based on a quick ctrl F search I found a small mention of the tie problem in the previous quarterly report:

from pdf p 87

Quote

• Owner concerns about integrity of concrete ties over time, (additional maintenance costs and impacts to CATS operations) have resulted in several meetings with CMC Senior Management, General Contractor and Supplier to address nonconformities. NCR 51 is still open. As of May, ties are still being repaired or replaced. Each load is inspected and any defective ties are returned to the vendor. The contractor’s daily inspection report indicates where and how many ties are replaced daily. Total inventory of noncompliant ties noted by CMC personnel at storage yard is 2,076 (data through May 2017). City and CMC senior management meeting in June to ensure issue contained, root cause identified and corrective/preventive actions are being implemented.

So it appears the issue has been known for at least several months and has been shared with the FTA and (technically) the public. FWIW the quarterly report does not take the tone that this is a critical issue.

[jednc]

19 minutes ago, kermit said:

Based on a quick ctrl F search I found a small mention of the tie problem in the previous quarterly report:

from pdf p 87

So it appears the issue has been known for at least several months and has been shared with the FTA and (technically) the public. FWIW the quarterly report does not take the tone that this is a critical issue.

Good find. I would say that it has absolutely been shared with the public not just as a technicality. The point of these reports is to inform about what's going on. It's up to the people who want to know the details to read these reports. It's not like it's hidden.

[UPNoDa]

They fail to mention the precise location of the repaired/replaced ties but I captured this on my run down Craighead today.........

 

I must add that the "rusted/weathered" look on those massive steel I-beams certainly fit in with the warehouse element in NoDa.

That or it's simply growing on me with no hopes of a finished product.

 

Edited July 25, 2017 by UPNoDa

[tarwater]

I would think all of the defective concrete ties have been replaced by now? They've sent the train all the way to UNCC as recently as a couple weeks ago. 

[Desert Power]

Wish this thing would open soon...

[kermit]

1 hour ago, tarwater said:

I would think all of the defective concrete ties have been replaced by now? They've sent the train all the way to UNCC as recently as a couple weeks ago. 

I think tie tie replacement issue remains a bit of a mystery. Cracked ones could still remain and not interfere with testing (their presence may reduce top speeds but that is not relevant yet). CATS appears to primarily be concerned with the long-term maintenance issues associated with a bad batch of ties and justifiably want them all to be changed out now to prevent headaches later.

If lots of cracked ties remain I would think Balfour Beatty would bring in another set of equipment (or two) and get the job knocked out quickly (its an almost entirely mechanical process) -- but one of us would certainly notice (and photograph) that. While I suspect that the bulk of this issue has been addressed (based on the most recent quarterly report and the absence of visible track work) the lack of followup on the hyperbolic channel 9 story (hello Observer???) leaves us not knowing how big or small the problem currently is.

[ajfunder]

WSOC claimed that they could only replace 30 ties a day. I am fairly familiar with railroad construction techniques and I know for a fact more ties than that can be replaced in a day. I have seen the freight railroads replace a few hundred in a mere few hours with all the mechanized equipment available today. 

Also they are really taking their times relocating the NCRR tracks. The new tracks are in place but not connected yet.

Edited July 29, 2017 by ajfunder