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CP 485 and 497 I did based on standard NS mnemonics practices, watching the bit patterns with traffic. For CP 482 and 483, I had "help".

Quicke question about the crossovers on the Porter Remote Track: what speeds are all the turnout speeds on it?

Curious about the west end at CP483 and the two pairs of crossovers at CP482 that connect it to Main 2.

If I recall correctly the best signal a train can get out of the siding in either direction is a Slow Clear.
The Porter Branch can get a medium signal.

justalurker66 wrote:If I recall correctly the best signal a train can get out of the siding in either direction is a Slow Clear.
The Porter Branch can get a medium signal.

The Porter Branch gets a medium? I always thought it was a slow speed signal, but if you're confident that works for me!

So the West End at CP 483 is slow, the western crossover at 482 is slow and the eastern crossover at 482 is medium speed, just to be sure?

Saturnalia wrote:The Porter Branch gets a medium? I always thought it was a slow speed signal, but if you're confident that works for me!

The Porter Branch signals can display a slow clear (bottom head green) but there is a green lamp in the second head, so it can also display a medium clear. The yellow lamp in the second head adds other medium aspects. The signal from the Michigan line has single red lamps for the top two heads, which would limit it to best signal being Slow Clear.

Saturnalia wrote:So the West End at CP 483 is slow, the western crossover at 482 is slow and the eastern crossover at 482 is medium speed, just to be sure?

Based on the signalling, yes. I believe all crossovers in 482 are medium speed, but someone who knows would need to confirm.

Back when the radio used to be free years ago, trains going from 1 to 2 west would call a limited clear at 482 at that crossover closest to the WB signals. That was the only higher speed crossover in the plant.

justalurker66 wrote:

Saturnalia wrote:The Porter Branch gets a medium? I always thought it was a slow speed signal, but if you're confident that works for me!

The Porter Branch signals can display a slow clear (bottom head green) but there is a green lamp in the second head, so it can also display a medium clear. The yellow lamp in the second head adds other medium aspects. The signal from the Michigan line has single red lamps for the top two heads, which would limit it to best signal being Slow Clear.

Hmmm. What would they need a Slow Clear off the Porter Branch then, if the crossover to get to M2 is a Medium Speed crossover. Because, of course, the only other route would be a restricting into the Porter Yard, something you can of course do with just two heads. It seems like they must have added in an extra head or something?

I'll have to look at my signal rules chart to see if there's anything odd that'd require that third head

justin_gram wrote:Back when the radio used to be free years ago, trains going from 1 to 2 west would call a limited clear at 482 at that crossover closest to the WB signals. That was the only higher speed crossover in the plant.

Okay so I wasn't just seeing things the one time I crossed over on Indiana 49 and swore that the WAS on Track One was giving a limited clear. I chalked it up to seeing things within that second or so I could see the signal - was driving at the time so I didn't get the best look! And that would make sense, since those trains taking that crossover always seemed to be at a bit more than 30 in my estimation.

So according to the signal chart I have, the only signals that'd require a third head are:

Medium Approach Medium |-G-Y-R
Approach Slow |-G-Y-R
Slow Clear |-G-R-R
Slow Approach |-FY-R-R

Or optionally, a three-head restricting, |-Y-R-R

I suppose the third head could be to give them Approach Slow, which would require that lowermost Green, perhaps if CP479, or previously 4791E or 4792E were Restricted, but I was always under the presumption that you'd normally get an Approach leading into those, which would be a Medium Approach in this case, which doesn't require that bottom head.

So I guess right now I'm assuming the signals off the Porter Branch are arranged as follows: |-RYG-RYG-R

I would expect it to be |-RYG-R or |-RYG-R-R otherwise, depending on if the route off the branch were Slow or Medium Speed.

How would you do a medium approach with two heads? Adding the third head makes Red over Yellow over Red the easy choice (then use Red over Red over Yellow for Restricting).

Medium Approach Medium is a good signal for eastbounds from the Porter Branch - especially after the installation of CP 479. Although I have seen an Approach Medium when the next signal isn't an interlocking. There are several signal locations where (in my opinion) the signals could be done with less heads. My opinion does not control the opinion of NS engineers.

justalurker66 wrote:How would you do a medium approach with two heads?

Red over flashing yellow, allows them to still use red over yellow for restricting. Have seen it quite a bit at the WAS CP 482 CSX connector.

justalurker66 wrote:Medium Approach Medium is a good signal for eastbounds from the Porter Branch - especially after the installation of CP 479.

Bingo that's the one I overlooked. And that goes indeed give us a good tree which matches what we see in the field:
|-RYG-RYG-R

So I believe our consensus is the following at CP482:
- Westernmost crossover from the Porter Branch: Slow Speed
- AMTK MI Line connection: Slow Speed
- Easternmost crossover between M1 and M2: Limited Speed
- All others: Medium Speed

Thanks for the help on CP482! While we're at it, can I get some confirmation on CP485 and CP487?

I show both crossovers at CP485 as Limited Speed, and at CP487, the easternmost at Slow Speed while the other westernmost two are Limited Speed?