4 replies to this topic

[MattW]

I know that non-FRA certified equipment will ever share rails with standard railroad trains at the same time, so you'll never see a Portland Streetcar cruising alongside a BNSF coal train, or a MARTA train blasting by a CSX intermodal the next track over, but what about the other way around? Loading gauge and technical issues aside, if for whatever reason say, Atlanta decided to use existing freight trackage instead of building new dedicated MARTA lines and used some kind of strange FRA-certified DEMU trainset outside of the existing third-rail separated lines, are there any regulations that prevent this?

[George Harris]

I know that non-FRA certified equipment will ever share rails with standard railroad trains at the same time, so you'll never see a Portland Streetcar cruising alongside a BNSF coal train, or a MARTA train blasting by a CSX intermodal the next track over, but what about the other way around? Loading gauge and technical issues aside, if for whatever reason say, Atlanta decided to use existing freight trackage instead of building new dedicated MARTA lines and used some kind of strange FRA-certified DEMU trainset outside of the existing third-rail separated lines, are there any regulations that prevent this?

NO

Edited by George Harris, 24 January 2012 - 03:22 AM.

[jis]

I know that non-FRA certified equipment will ever share rails with standard railroad trains at the same time, so you'll never see a Portland Streetcar cruising alongside a BNSF coal train, or a MARTA train blasting by a CSX intermodal the next track over,

As long as the two tracks are not connected and have sufficient track center distance there is nothing in the regulations that prohibits a MARTA train blasting by a CSX coal train on adjacent tracks. This sort of thing incidentally happens all the time on WMATA Red Line in Washington DC.

but what about the other way around? Loading gauge and technical issues aside, if for whatever reason say, Atlanta decided to use existing freight trackage instead of building new dedicated MARTA lines and used some kind of strange FRA-certified DEMU trainset outside of the existing third-rail separated lines, are there any regulations that prevent this?

As George said "No". And why would an FRA compliant DEMU be strange? Of course said FRA compliant DEMU will not be able to share trackage without temporal separation with non-FRA compliant MARTA trains anywhere.

[MattW]

Thanks Jis, so based on what I'm gathering, the connection (or proximity) is more the issue to the FRA than the equipment then? I know that on FRA trackage such as the RiverLine or Baltimore LRT they use temporal separation, but for a non-FRA line, it would suddenly require FRA oversight (and temporal separation) if FRA equipment operated over it then?
I called the DEMU strange I guess because it seems we can't even get a standard DMU production line going so I was thinking a DEMU would be worse

Edited by MattW, 25 January 2012 - 02:10 PM.

[jis]

Thanks Jis, so based on what I'm gathering, the connection (or proximity) is more the issue to the FRA than the equipment then? I know that on FRA trackage such as the RiverLine or Baltimore LRT they use temporal separation, but for a non-FRA line, it would suddenly require FRA oversight (and temporal separation) if FRA equipment operated over it then?

The core issue is that if an FRA compliant piece of equipment crashes into a FRA-non-compliant one, it will likely do much graver damage to the FRA-non-compliant equipment than what would be the case if it were FRA compliant. Hence the general rule that FRA compliant equipment must be "positively separated" from FRA non-compliant equipment. This means that there should be next to zero probability that two such pieces of equipment land up on the same track at the same spot at the same time.

This separation can be achieved roughly speaking in one of three ways:

1. Do not ever let them on the same track, or if you allow such then the track must be taken out of regular service, blue flagged etc. for the duration.

2. Let them on the same track but never in the same time window. So the shared track remains in FRA mode a for some time and then all FRA traffic is cleared from it and the track is placed into non-FRA mode for some time, and at the end of that time all non-FRA equipment is cleared and then the track reverts back to FRA mode. This is the sort of temporal separation that is used on the RiverLINE. There is no general FRA rule about this, and these are all operated under special waivers.

3. A much much more capable signaling system and specially designed track layout which with proper failsafe makes it impossible for any two trains to get on the same track and get to the same point at the same time. This is the system that the Europeans use to allow mixing of lightweight and heavyweight trains to share track facilities (e.g. LRT and mainline EMUs and DMUs between Lauterbach and Thann just outside of Mulhouse in France). FRA is currently experimenting with such but has nit done any rulemaking in this area
yet, nor done any waivers based on this except in one very short segment on the RiverLINE for a very short period of time during each day.

So it is not just FRA but the common boss of FRA and FTA, i.e. the DoT would possibly have concerns if an FRA compliant equipment starts running on a transit track governed by FTA mixing with non-FRA-compliant equipment. And of course NTSB will go ape-sh*t.