I didn't really want to start a thread just for this, but after a lot of googling which did not lead to much I fear I have no other option. Does anyone have any in-depth insight on how does ACSES work? How to judge whether the one made by DTG is good? Obviously the random speed drops on Boston Sprinter were a red flag even for the ignorants like myself, later (apparently) confirmed by more knowledgeable people that it was indeed a bug. I roughly know how it works and what's its purpose, but nothing more than that. For example in this video I found about ACSES on a SEPTA line it seems like the speed gradually drops, like it did on the old NEC: NY, but it's no longer the case since NEC: Boston Obviously I don't want to claim that ACSES is right or wrong, I just want to learn about it before judging it. It's possible that video is outdated, or SEPTA uses a slightly different system. Again, I don't know.
Well, that's just based on a train sim TSW isn't it? And again, if the SEPTA system is different, how accurate is the Metro North one? Is it the same as the one used by Amtrak? Just to be clear, I don't want a tutorial for using ACSES. But rather have some sources to judge wether or not it's accurate.
I just watched it, while he credits Alstom at the end. I do still feel it's more of a tutorial on the system in the game rather than being centred on the real system. Don't get me wrong, it's a great video and the guy seems really cool, but it's not really what I was looking for. Why is the SEPTA system different then?
ACSES is essentially monitoring track speed. It calculates a braking curve, to bring you down to the next speed limit in time. It kind of works like LZB on German trains, except this isn't "live."
Did you check this out? (click on the little arrow to get to the original post and its attached PDF file) Otherwise, I’m in the same boat as you. Never could find any official documentation on ACSES online.
Yes, I do know that. Look at the video I posted at the beginning, that, as far the author claims, it's ACSES operating on a SEPTA Silverliner V. Why is the interface different, and it seems to work differently, closely to how the system was modelled in the old New York route? Is there/What is the difference between the SEPTA system and the Amtrak system? If there are different systems, does MTA use the same system as Amtrak? Does the driver actually use the suppression brake position each time he has to brake, does he rely more on track knowledge or does ACSES actually give him the information about slowing down before he's "forced" to use suppression? As I said in the original post, I roughly know how it works and what's its purpose, but more in-depth information from a driver's perspective, how to interact with it and the information it gives you, the exact way the ADU functions. To me (which I repeat, I am ignorant from that point of view) the system built on RH NEC and Harlem line seems a bit crude, and I was expecting something more like the SEPTA video, which "guides" the engineer in following the correct braking curve, like ETCS does. The difference is that for ETCS there are (actually a surprising) amount of videos showing the displays and what the system is telling the driver and how the driver reacts. But that is completely absent for ACSES. It's just personal curiosity of course, it's just that I imagine there are some people in this forum that know more than me, and I would be interested in actually learning in-depth how the system works. Thanks for trying to help, I appreciate it but I was looking for a different set of information. I missed that! Thank you, now some things are starting to make more sense, the distinction between the different curves is crucial to understand the use of the suppression setting for example. And he mentions drivers use that regularly so that answers another one of my questions! Still a lot to learn though, but that's a great start.
The engineers use route knowledge to know the speeds. You shouldn't rely on ACSES to tell you. It's only there to enforce the limits.
That makes sense of course, route knowledge is still a thing, and that would explain why ACSES doesn't guide the engineer down the braking curve, like ETCS does or the SEPTA system from that video (which is 5 years ago so it might be an outdated, older version of the same system) does. Sadly at this point, the fact that engineers have to rely on track knowledge is a fact, but the latest part about ACSES is speculation.
Glad you found my guide useful! If you have any specific questions about ACSES, I am happy to answer them.
Thank you for the guide! As far as specific questions, I would have a few if you don't mind. The speed drops directly from the current to next speed limit in case of a reduction, istead of "counting down" the braking curve (hopefully that makes sense), like similar systems such as ETCS do, is that correct? Do SEPTA, Amtrak and Metro North use the same system? Again, I guess so otherwise interoperability on the NEC would be a nightmare. Do you think the TSW rendition is accurate? (On the Boston and Harlem route which I believe use the same - or very similar - systems in game) If not, what are the biggest differences compared to real life?
FD, Amtrak's implementation does not visually count down the maximum authorized speed like SEPTA's does. If the alert curve is reached when approaching a restriction, the speed of that new restriction immediately becomes the maximum authorized speed and the engineer must brake/acknowledge accordingly. The braking curve calculations are internal to the ACSES computer onboard the train and not visible to the engineer. SEPTA, Amtrak, LIRR, and Metro-North all use ACSES. They really only differ in how the information is displayed to the engineer on the Aspect Display Unit. For example, SEPTA making the maximum authorized speed of the alert curve visible to the engineer, while Amtrak/LIRR/MNRR do not. The TSW rendition is somewhat accurate, but lacks proper braking curves, positive train stop, and the '--' on the ADU when in non-ACSES territory. I'm not sure of everything that was modified in Harlem, but they added the two dashes when in non-ACSES territory. It's progress.
I see, that makes sense. Thanks you very much for clearing these points up. I think it's possible they implemented some sort of braking curves. I can't see Rivet's ETCS working without those, so hopefully that made it's way onto the Harlem ACSES? Again, appreciate the information, thank you very much.
Oh they're certainly there (Harlem ACSES blueprints were originally cloned from Boston), but the Boston ones aren't completely accurate. That's all I meant.
So what about responses to suppression braking differing between MTA routes and Amtrak? Seems that the response to Amtrak's implementation dropping the speed limit is "throttle off, brakes to suppression, acknowledge". But the MTA routes are "better have your route knowledge in order or I'm emergency braking, punk"...?
Does using ATC\ACSES on Boston Sprinter sometimes make you late? I was trying the F40 service Boston-Providence #809 with ATC+ACSES turned on and could not stay on time and could only earn the silver medal. Three attempts gave me the same result. I then tried it without ATC or ACSES and just travelled at line speed I was able to stay pretty much right on time and got the gold. I'm wondering are the ATC\ACSES speed limits not correct or did the service's schedule simply not take into account those reduced speeds? DW
Nah the systems are broken. Could also be that the service timings don't match how you would run the train with proper safety systems
Its all well and good saying the systems are borked, but theyve been borked since day 1. Any chance of actually ever having these fixed please?
Is the existence of ACSES the reason why there are no wayside speed limit signs in Boston Sprinter? Is the reasoning similar to the TVM system used on HS1 in the SEHS route, e.g. "you're going too fast to read the signs, so the in-cab display will tell you how fast to go" instead?
In whatever free time i have, mind you. Been involved in a huge project the past two months so this hasn't received any attention
Awesome! I look forward to seeing what it is then! Until then, I'll be here playing the guessing game I suppose. That has me very excited though, I must say!
I am so glad I found this thread. Older in years, but new to TSW2 and I was struggling to understand how the ACSES system worked as I encountered it on Metro North Harlem (hope someday to see New Haven line as well.) Can anybody here tell me what the indicator N, L, M, etc levels stand for? I've been racking my brain trying to figure those out. Any chance we'll ever see any NYC actual subway lines in TSW2? (Tried world of Subways #4, just didn't so it for me. WOS 1's PATH simulation was't too bad, but not up to TSW2 quality. Played around with Trainz and Trainz:ANE but just never got into it. Maybe that's because I'm really just interested in driving, and not building my own stuff.
And “R” stands for Restricted Cab meaning not exceeding 15MPH and being prepared to stop short of other trains or obstructions.
That's common on Harlem Line you see this right at the start of Hudson Line 787 GCT to Croton. NEC The Boston Depot Twilight Shoreliner Train 66
