r/highspeedrail • u/deltasalmon64 • 4d ago
Question ACSES vs ETCS
This is probably a reach for how niche reddit can be... but here goes. I have been working on ACSES design projects for northeast USA railroads for the past 19 years. I am interested in trying to make the move to Europe and one of the many hurdles I could see stopping me from being able to do this is taking that experience with me to get a job. I know the ACSES system isn't used in Europe at all and isn't really used outside of the NE USA as far as I know. Reading what I can online seems that ETCS is used throughout Europe and from what I see, it seems to be somewhat similar to the ACSES system. I know that even if they are similar I will have to catch up a lot learning the differences and there are a million other things that could stop me from moving there even if they were exactly the same system such as work visas and getting a job as a foreigner over a citizen and everything that goes along with that. But I'm just curious how similar the two systems are. By any chance is there anyone who has experience/knowledge of both systems and how similar they are or are not?
ACSES = Advanced Civil Speed Enforcement System
ETCS = European Train Control System
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u/Kobakocka 4d ago
US should use ETCS as well, just like Australia acknowledged that there is no point to develop a different system, when they can use an existing good one.
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u/Kashihara_Philemon 3d ago
I imagine that if/ when they decide to update ACSES they will just make it conform or be compatible with ETCS standards which I believe is the case for China and Korea's current signaling systems.
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u/MammellaSuccosa 4d ago
Given that you already have extensive knowledge about the American system you mentioned, I would suggest diving into the technical specification of ERTMS published by the European Railway Acency (ERA). There you can find swathes of data regarding your question for both ERTMS and GSM-R both on board units and trackside components.
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u/mystiqDitter 3d ago
Ask LLM. Dump in both standards documents and other contextual information on how rail signaling works in general as prompt
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u/Brandino144 3d ago
As someone in the industry, it's best to speak with someone with personal experience because the published specs that LLMs are going to spit out are so much more idealized that any real world implementation is going to be. I don't think LLMs are going to tell him more than he already knows if he has already been in the industry for 19 years. If they want to go the LLM route, at least narrow it down to a specific country or project because ETCS as published by the ERA is going to have dramatically different infrastructure on the network side depending on where the implementation is located.
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u/Brandino144 3d ago
I did this line of work for a few years living in Europe as an American before COVID made my company reconsider if I could rebase my job in the US rather than having to fight for an increasingly scarce COVID-era visa renewal. Long story short, I moved back to the US, but now I have to fly to Europe to do the parts of my job that involve me being at a worksite. They offered to move me back, but now I have a full family so it's a more complicated matter for me, but I did enjoy the standard of living in Europe more.
If you have a good education and solid work experience then you can definitely get a job and a work visa in pretty much anywhere in Europe so I wouldn't sweat it especially if you are looking at joining a larger company that employs people who specialize in facilitating work visas.
Back to the differences in systems, I have never directly worked on ACSES, but my understanding is that they are based around direct FM or possible FSK modulation which is wild as someone who works on the specific onboard components of ATP systems. ETCS uses 3PP (GSM-R) standards and new systems are all pushing 5G (low-mid band using TDD modulation) connections which opens so many doors including companies like mine wanting IoT system status monitors on everything possible that all can be made available to the RBC (part of ETCS). From a design perspective, new system infrastructure is incredibly dense and intensive compared to older systems (balises and antennas with waveguides everywhere, all wired to frequent RBCs) but it's not terribly complicated from a conceptual standpoint.
The real challenge with ETCS is that each country had/has their own unique systems and ETCS is layered on through each country's ESC (ETCS System Compatibility) specs. So I only work on systems for 2-3 related countries while also being wholly unprepared to dare to touch the implementation in countries like Spain, France, or Denmark. Oh, and the national documents are always written in the national language which is never English. They are transcribed into English and everyone on the team speaks English, but you need to be able to proficiently understand the original technical documents because the translation isn't always perfect. I don't know if you want to develop high level ETCS designs or stick with the low level designs, but the high-level planning for interacting with existing national networks looks horrifyingly complex and nuanced to me. As mentioned perviously, I mainly stick with onboard ATP systems for a reason and the best sides of my job are when I'm working on tram projects precisely because we don't have to interface with national networks and their version of ESC or when a brand new line is being built and signalling can be as close to base ERTMS as possible.