robmausser
Senior Member
Metrolinx should talk with VIA, CP and CN and coordinate on what plans for PTC etc they have, and get a written contractual agreement from all 3.
However I am sure getting that would be the longest red tape in the world.
|
|
|
- Thread starter mdrejhon
- Start date
However I am sure getting that would be the longest red tape in the world.
Bureaucromancer
Active Member
With the added note that most of the forms of North American PTC ARE fundamentally fixed block.
Urban Sky
Senior Member
VIA is a decision taker here: They will need to install whatever its host railroads install and has zero incentive to chose anything else for its own infrastructure…
robmausser
Senior Member
Right, its real focus if I understand is increased safety, not allowing more trains to operate together
smallspy
Senior Member
Not fundamentally. The signals delineate the blocks, and they are fixed in the ground. The control length for each block, while it may vary from block-to-block, does not change once it is set up. PTC simply overlays onto this existing equipment.
There are no moving block signal systems in place and operational anywhere in the contiguous railway system of North America. There are exceedingly few in use on any of the heavy rail systems on the planet.
There are two major exceptions to this - one is that there are a number of isolated natural resource railroads that have installed moving-block signal systems, but they use standardized equipment running in fixed length consists. The other is that there are a number of metro systems - again, that use standardized equipment running in fixed-length consists - that happen to interface with the wider rail network. In those cases however, the moving-block signalling system is only located where the specialized equipment can run.
Yes, ETCS level 3 allows for moving-block in theory, but there have been no installations of it up to this point, and in fact I think that is has only been looked at in just two resignalling cases.
Dan
MovingBlock
New Member
There are fixed-block signalling systems where there is no lineside signalling, such as ETCS Level 2, LZB, TVM and BACC. Transmission of the MA occurs by radio (ETCS L2), induction loop (LZB) or coded track circuit (TVM & BACC), so there is no need for lineside signals (there's usually a marker board to denote where to stop). It's possible in the distant future that we could see ETCS Level 2 in place on some locations in the GO Network.
I know of one installation (the Wuppertal hanging railway), but it is a very special case. ETCS Level 3 (which unlike CBTC has no track-based vacancy detection at all) is unlikely to ever be implemented in a mainline or metro context for a variety of safety reasons.
smallspy
Senior Member
100 percent.
Doesn't change the fact that they're still fixed block lengths, though. Or that they don't need PTC, as they use their own standards and equipment for maintaining safe distances.
Sure, but how many other German railroads are going to be operating on it?
At least with the projects that are being looked at in Switzerland and Austria there will be mixed operations on it.
Dan
reaperexpress
Senior Member
Something that the Netherlands realized is that very small fixed blocks are functionally identical to moving blocks. Even with a moving block system a train's movement authority only gets updated every few seconds anyway.
This is why the leading proposal to upgrade capacity on the core network is not to upgrade to ETCS L3, but rather to use L2 and subdivide each physical block into many virtual blocks. Trains which have onboard train integrity detection (passenger trains) can use the micro blocks and travel close together, while freight trains use the much larger physical blocks. This avoids the need to retrofit every freight car in Europe with train integrity support, which was deemed an insurmountable obstacle for the foreseeable future.
In addition to having different block sizes for differently equipped trains, it is also possible to have multiple overlaid signal systems. For example, the line from Utrecht to Amsterdam is signalled with both ETCS and the legacy ATB system. Most NS trains are not equipped with ETCS so they're limited to ATB's 140 km/h cap, but ETCS equipped trains such as the ICE 3M or the ICNG can switch to ETCS to unlock higher track speeds (in this case 160 km/h).
Freight operators in the Netherlands (the largest of which is Deutsche Bahn) have been advocating for ETCS rollout so they don't need to keep maintaining redundant ATB equipment on their trains. The freight mainline between the Port of Rotterdam and the German border is already fully ETCS but freight trains have ATB equipment in case there's an incident and they need to divert into a different route. One of the top priorities for ETCS rollout is therefore to convert the most common freight diversion route (via Dordrecht and Breda) to ETCS.
This is why the leading proposal to upgrade capacity on the core network is not to upgrade to ETCS L3, but rather to use L2 and subdivide each physical block into many virtual blocks. Trains which have onboard train integrity detection (passenger trains) can use the micro blocks and travel close together, while freight trains use the much larger physical blocks. This avoids the need to retrofit every freight car in Europe with train integrity support, which was deemed an insurmountable obstacle for the foreseeable future.
In addition to having different block sizes for differently equipped trains, it is also possible to have multiple overlaid signal systems. For example, the line from Utrecht to Amsterdam is signalled with both ETCS and the legacy ATB system. Most NS trains are not equipped with ETCS so they're limited to ATB's 140 km/h cap, but ETCS equipped trains such as the ICE 3M or the ICNG can switch to ETCS to unlock higher track speeds (in this case 160 km/h).
Freight operators in the Netherlands (the largest of which is Deutsche Bahn) have been advocating for ETCS rollout so they don't need to keep maintaining redundant ATB equipment on their trains. The freight mainline between the Port of Rotterdam and the German border is already fully ETCS but freight trains have ATB equipment in case there's an incident and they need to divert into a different route. One of the top priorities for ETCS rollout is therefore to convert the most common freight diversion route (via Dordrecht and Breda) to ETCS.
Last edited:
smallspy
Senior Member
It's not just the Dutch who've realized this.
It's on this basis that many modern subway systems design their signal systems. And Metrolinx did as well, with the Weston Sub.
Dan
rbt
Senior Member
This is/was Verster's preferred approach: very short physical blocks with traditional signals. In an interview (March?) he said he was discouraging relying on ECTS v2 because it's difficult to firm up the implementation timeline for a Canadian implementation.
Last edited:
ARG1
Senior Member
rbt
Senior Member
I think it was this interview posted in early April but I didn't confirm (other than I had "liked it" and it's from the right time period). It doesn't seem to have a transcript for a quick scan.
IIRC, it's mostly a discussion about the tendering process for OnCorr and his remark was an aside about ongoing efforts to derisk the project with the vendor.
Last edited:
reaperexpress
Senior Member
Yes obviously everyone knows that shorter blocks means shorter headways, but my point is that ProRail has devised a practical way to actually make the blocks so short that the movement authority refreshes as frequently as a with a moving block system. So we're talking a new block every five seconds or so. That means multiple blocks within the length of a platform. Neither the Weston sub nor a fixed block subway system come anywhere near the frequency of movement authority updates of a moving block system.
The Dutch innovation is to use virtual blocks which exist purely within the digital realm (i.e. without any associated track circuits, axle counters or physical signals) as a subdivision of physical blocks which do exist with axle counters. It would be outrageously expensive to install that many physical signals and track circuits, and even if we did, it would be absurd to expect drivers to be able to read a new physical signal every five seconds along the line.
Last edited:
smallspy
Senior Member
It's on this basis that the original SelTrac signal system was designed, built and operated. If the Dutch have manged to port this to a heavy rail application, this is quite a big deal.
Dan
reaperexpress
Senior Member
They seem to think it is a big deal. They basically combined components of ETCS L2 and ETCS L3 to make what they unofficially call ETCS L2.5, which originated in their attempt to implement L3. As far as I'm aware, nobody has implemented L3 on a line shared with freight yet and ProRail was facing some pretty big challenges trying to get that to work.