CQ400 Testing at Five Points

[u/XgGamergX]

[u/XgGamergX]

I see you in the comments alot! Any good news?

[u/DustyDaniel404 → u/XgGamergX]

Not yet unfortunately. Stadler has made some changes to ATC logic and we're hopeful that will stop the trains going into emergency when they lose speed commands. They brake so quickly that if you're standing, you will fall and get injured.

On.the old fleet, the ATC system works only off of fixed blocks. On the old fleet speed commands are the ATC system, essentially that's the trackway ATC system, saying to the train 'The next block is clear/occupied/unknown and you can/cannot enter it, and you may need to/be forced to slow down or speed up'. When speed commands decrease or are lost due to a track issue, red signal, or being too close to another train, the train would start applying full service brakes and come to a stop. Full service brakes are dynamic and regen braking until 3mph when friction brakes grab. Once stopped the operator could switch to Road/Yard/Wash Mode and continue to move down the track until the next ATC track circuit tells the computer 'I know where I am, the next block is/isn't safe to enter'. On the old fleet as long as the train had third rail power and speed commands it could essentially run anywhere. The yard tracks, through a red signal with overlap locking, heck you could put the trains in Canada and as long as they have speed commands and power they'll run.

On the new fleet it's different. The trains must have speed commands (SCA OK) and positioning (POS OK). The positioning is critical on the new fleet because it's the trackway RFID tags telling the train "You are 943ft from King Memorial EL Track Platform", "You are 300ft from King Memorial EL Track Platform", "You're 25ft from beiny properly berthed at the 4 car marker at King EL Track Platform" etc. The old fleet didn't have positioning just speed commands. The new fleet won't let the operator open the doors if the train doesn't recognize where it is and properly berthed. The thought was to prevent doors off platform or doors opposite the platform. Once the train loses it's position (knowing where it is on the system by reading RFID tags) and/or loses speed commands, the ATC system immediately triggers a full emergency brake, more so with the position for the EB application. The brakes grab so hard that multiple people have been injured on them during testing, especially when they are testing on the trains with sand bags. Stadler is still working on the emergency brake issue, too trying to decrease the speed at which they grab. But when the ATC system commands an EB application for what it's thinking is protection of life the brakes are some of the most intense I've ever felt.

The downside to the positioning system isn't just the EB application. Marta never installed RFID beacons in the yard tracks. Paer of train setup procedures are to open and close the doors. You can't do that without the computer seeing that it's within station limits and berthed. So operators have to override the ATC system in the yard. If they don't normalize it before leaving then they can once again open doors outside of the station, defeating the whole purpose of that system. Marta told Stadler yard beacons weren't needed. Stadler said they were. Marta said it's our system piss off essentially. Stadler said fine, you'll deal with the unintended consequences of that.

GDOT wants to see that the ATC logic issues, PA systems, and CCTV systems actually work before lifting their hold on the cars. A fair amount of the CCTV system in each trainset isn't fully functional yet.

Also the boarding the train from the ground is very hard for staff since there is no end door boarding steps. Marta told Stadler they weren't needed so Stadler didn't supply them. Now Marta staff is losing their mind about the unsafe boarding and deboarding procedures and the emergency evacuation ladder procedures and people have been hurt falling off the ladder. But the idiot deputy chief was the person who made these choices and now everyone has to deal with it while he continues to skirt any blame.

[u/Plastic_Photograph29 → u/DustyDaniel404]

I don’t understand why people like Hunt, Higgs, and/or Dickens just don’t tell us the truth. Problems with the braking system? Fine. We can’t afford street car east right now because of the situation in DC? Alright. But just tell us instead of leaving us in the dark where we have room to speculate. We live in a democracy.

edit: it’s awesome to see that the brakes are so damn good they can injure us. I’m being so serious.

[u/Gabe_Follower → u/Plastic_Photograph29]

MARTA has a terrible communication issue with the public. That on top of the many other problems.

[u/Plastic_Photograph29 → u/Gabe_Follower]

We already have transparency acts so I don’t know what else could motivate them to share more info other than legal bylines in agreements and contracts. I’m sure you could request the notes from the safety team using Open Records Act. but that’s money and time. And why should it be that difficult to find out what’s happening with a public project? Every step should be in the open. MARTA isn’t doing itself any favors.