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  • High-Speed Signals (>79 mph)

  • Discussion related to Amtrak also known as the National Railroad Passenger Corp.
Discussion related to Amtrak also known as the National Railroad Passenger Corp.

Moderators: GirlOnTheTrain, mtuandrew, Tadman

 #1556177  by electricron
 
TurningOfTheWheel wrote: Sat Nov 07, 2020 12:55 pm Did they give a reason for abandoning the 120mph goal? Is it an issue with I-ETMS?
FRA regulations on maximum speeds have been repeated so many times on so many threads, maybe railroad.net administrators should post them here and place it at the top as the first thread to be read? That way questions like this one we would not have to rehash the existing regulations over and over again.
Keeping it simple as much as possible;
No Classification no passenger trains allowed
Class 1 allows speeds up to 15 mph
Class 2 allows speeds up to 30 mph
Class 3 allows speeds up to 60 mph. No block signaling required.
Class 4 allows speeds up to 79 mph. It requires block signaling using wayside semaphores or lights.
Class 5 allows speeds up to 90 mph. It requires block signaling with in-cab signals.
Class 6 allows speeds up to 110 mph. It requires reinforced gates at all public crossings.
Class 7 allows speeds up to 125 mph. It requires reinforced gates at all (+ private) crossings.
Class 8 allows speeds up to 160 mph. It requires complete grade separations at all crossings.

Illinois was never going to require reinforces crossings at private grade crossings, therefore the train speeds were never going to be faster than 110 mph. Why anyone thinks that the Midwest trains will be going 120-125 mph I have no idea.

Additionally, there are many more details with the track classifications by the FRA, take the time to read the appropriate regulations one night you might need help going to sleep. ;)
I kept the limiting factors as simple as I could earlier in this thread.
 #1556209  by JimBoylan
 
Do Class 4 and Class 5 still allow alternatives to wayside semaphores or lights, and in-cab signals, like Automatic Train Control, Automatic Train Stop, or Positive Train Control?
 #1556243  by electricron
 
JimBoylan wrote: Sun Nov 08, 2020 7:39 am Do Class 4 and Class 5 still allow alternatives to wayside semaphores or lights, and in-cab signals, like Automatic Train Control, Automatic Train Stop, or Positive Train Control?
Again, keeping the answer as simple as possible;
ATS is designed to work with way side signals.
ATC is designed to work with in-cab signals.
PTC is designed to work with both way side and in-cab signals.

The key words in all three statements above was "work with".
 #1556496  by WhartonAndNorthern
 
electricron wrote: Mon Nov 09, 2020 4:45 am
JimBoylan wrote: Sun Nov 08, 2020 7:39 am Do Class 4 and Class 5 still allow alternatives to wayside semaphores or lights, and in-cab signals, like Automatic Train Control, Automatic Train Stop, or Positive Train Control?
Again, keeping the answer as simple as possible;
ATS is designed to work with way side signals.
ATC is designed to work with in-cab signals.
PTC is designed to work with both way side and in-cab signals.

The key words in all three statements above was "work with".
However the regulations that set railway speed limits list PTC as an option instead of waysides (automatic block) for 59 mph and instead of ATC/ATS for 79 mph operation. I believe they envision that there's room for a future "moving block" PTC system that can one day replace an automatic block system and hopefully provide an "easy" (HA!) upgrade for dark territory.
 #1556501  by electricron
 
Wiki on Moving Block Train Signaling
https://en.wikipedia.org/wiki/Moving_block
How moving blocks work
https://web.archive.org/web/20090209014 ... txt3.shtml

Nowhere in the USA uses it to date, and nowhere in the USA is actively planning on using it.
Most freight, commuter, and intercity passenger trains in the USA already have wayside or in-cab signaling systems, just about 100% of them are adding PTC on top of their existing systems, my "with" phrase in an earlier reply.

Texas Central will be using the Japanese Shinkansen signaling system, which is an ATC system using stationary blocks. This wiki explains how it works well/
https://en.wikipedia.org/wiki/Automatic_train_control
Japan Central uses an ATC-NS system which is digital.
The digital ATC system uses the track circuits to detect the presence of a train in the section and then transmits digital data from wayside equipment to the train on the track circuit numbers, the number of clear sections (track circuits) to the next train ahead, and the platform that the train will arrive at. The received data is compared with data about track circuit numbers saved in the train on-board memory and the distance to the next train ahead is computed. The on-board memory also saves data on track gradients, and speed limits over curves and points. All this data forms the basis for ATC decisions when controlling the service brakes and stopping the train.[3]
In a digital ATC system, the running pattern creates determines the braking curve to stop the train before it enters the next track section ahead occupied by another train. An alarm sounds when the train approaches the braking pattern and the brakes are applied when the braking pattern is exceeded. The brakes are applied lightly first to ensure better ride comfort, and then more strongly until the optimum deceleration is attained. The brakes are applied more lightly when the train speed drops to a set speed below the speed limit. Regulating the braking force in this way permits the train to decelerate in accordance with the braking pattern, while ensuring ride comfort.[3]
There is also an emergency braking pattern outside the normal braking pattern and the ATC system applies the emergency brakes if the train speed exceeds this emergency braking pattern.

It does not use moving blocks.
 #1556526  by mtuandrew
 
David Benton wrote: Wed Nov 11, 2020 11:23 pm An alternative to moving block system, would be to simply have more, shorter blocks. especially in slow speed areas.
I’m not sure the block length for the ex-Alton Railroad, but that is common for higher-speed American roads. They have a special signal aspect (often a flashing green or white) above the usual lights that indicates multiple advance blocks are clear and a train can exceed 79 mph. Freight roads don’t like them because they cost extra money to maintain with no added benefit to them.
 #1556595  by GWoodle
 
mtuandrew wrote: Thu Nov 12, 2020 8:39 am
David Benton wrote: Wed Nov 11, 2020 11:23 pm An alternative to moving block system, would be to simply have more, shorter blocks. especially in slow speed areas.
I’m not sure the block length for the ex-Alton Railroad, but that is common for higher-speed American roads. They have a special signal aspect (often a flashing green or white) above the usual lights that indicates multiple advance blocks are clear and a train can exceed 79 mph. Freight roads don’t like them because they cost extra money to maintain with no added benefit to them.
The old Alton GM&O used B&O signal system installed in the 1920's. UP & CN should have replaced it in the last few years.
 #1556738  by David Benton
 
I think it was a orphan system , they tried to reinvent the wheel, instead of going with a tried and true system like the NEC ones. Same with the Michigan system, one could be forgiven for wondering if they were trying to spend as much money as possible.
 #1556747  by mtuandrew
 
David Benton wrote: Sun Nov 15, 2020 4:50 am I think it was a orphan system , they tried to reinvent the wheel, instead of going with a tried and true system like the NEC ones. Same with the Michigan system, one could be forgiven for wondering if they were trying to spend as much money as possible.
Less an orphan, more a system that didn’t win. ITCS, the GE-built system on the Michigan Line, was pretty early and pretty robust. I’m not sure why more roads didn’t adopt it. I can’t currently find more info on the former Illinois system but I think it was called ASES; they’re re-standardizing on Wabtec’s I-ETMS which has become the de facto American freight standard. Theoretically I-ETMS should be good for 110 mph operation, so I’m not sure what’s holding them up.

The NEC’s ACSES II is actually more robust and doesn’t depend on GPS. I think it is a descendant of some of the European systems that include wayside and in-track transponders. It’s good for a system where you don’t mind spending more on physical infrastructure that ties into existing cab and wayside signals.
 #1556797  by electricron
 
R36 Combine Coach wrote: Sun Nov 15, 2020 7:01 pm What FRA class is the line in SE Conn (with crossings)? They do have quad gate protection.
Class 7 where there are at-grade crossings, and Class 8 where there are grade separations at crossings. The trains are not allowed to go faster than 125 mph where there are at-grade crossings.