Cab Signal question

[i8itall4u]

I've always wondered.... I don't know if this is still current but, cab signals on the Brown line would clear from whatever restricted speed to 55 relative to the train's length. In other words, 2, 4 or 6 car trains clearing a curve would immediately go to 55. On other lines speeds were or are limited to a 10 car clearance. That is, cab signals don't go to 55 until for 10 car lengths, even though a 2, 4, 6 or 8 car train would be clear. Many times 2 car trains are seen moving out 10 car lenths beyond a curve at 15 mph.

Can you elaborate chicagopcclcar?

[chicagopcclcar]

I don't think you are actually seeing what you're describing...that the cab signal system allows for different train lengths to get higher speeds after a restriction at different points. The signal bonds are in the track structure and that location doesn't change. True the 3200s on the Brown line have transponders that send out informtion, the 2400s don't. A test I would suggest is monitor just one curve at one location and not be overwhelmed by the dozens of curve restrictions...and note where and when the signal release is received on different length trains...four cars and eight cars on the Brown. I'm confident you'll find the release is in the same place, but it is important to be concentrated on only one curve or two.

[Kimball401]

I have seen that happened many times at kimball as well as Montrose bend. (Damen to Montrose)

[chicagopcclcar]

Kimball401, on 01 Aug 2013 - 18:25, said:

I have seen that happened many times at kimball as well as Montrose bend. (Damen to Montrose)

You've seen "what" happen???

Again, your original description is not definite enough, its too general in nature. For instance, you say a 2,4,6 car train.....no mainline line runs 2 car trains. Mainlines only run two lengths....4 and 6s or 4 and 8s. Or in the case of the Pink, only fours. A mainline that runs 8s, never runs 6s.

Above all, signal clearing is at the signal bonds. The easiest explanation of different clearings would be that there was a train ahead. And there are all sorts of distances behind a train before the cab signal will clear to 15 MPH, 25,MPH, etc.

I was going to suggest that if you're really feeling investigative, the curve at Ravenswood sounds like a good location. Ride NB from Montrose, noting how far the leader was. Note when the signal clears. Go back, do it again...3rd and 4th time for scientific accuracy. But wait, isn't the cab signal display in 3200s on the left cab side. How can you see it clear to a less restrictive indication?

[Kimball401]

You've seen "what" happen???

Again, your original description is not definite enough, its too general in nature. For instance, you say a 2,4,6 car train.....no mainline line runs 2 car trains. Mainlines only run two lengths....4 and 6s or 4 and 8s. Or in the case of the Pink, only fours. A mainline that runs 8s, never runs 6s.

Above all, signal clearing is at the signal bonds. The easiest explanation of different clearings would be that there was a train ahead. And there are all sorts of distances behind a train before the cab signal will clear to 15 MPH, 25,MPH, etc.

I was going to suggest that if you're really feeling investigative, the curve at Ravenswood sounds like a good location. Ride NB from Montrose, noting how far the leader was. Note when the signal clears. Go back, do it again...3rd and 4th time for scientific accuracy. But wait, isn't the cab signal display in 3200s on the right side. How can you see it clear to a less restrictive indication?

Well its on the lef left and its going NB 55,curve 35 ,55 after 4 cars clear into Damen then 35 to Western.

As for your car knowledge im not trying to say your wrong but ive seen two car pink line trains late sunday evenings 10-1am ish

buts thats before the 5000's came into play

the last time i rode (about a month ago