Discussion relating to the operations of MTA MetroNorth Railroad including west of Hudson operations and discussion of CtDOT sponsored rail operations such as Shore Line East and the Springfield to New Haven Hartford Line

Moderators: GirlOnTheTrain, nomis, FL9AC, Jeff Smith

  by harmon44
 
Last week I noticed a signal aspect on the Hudson line at the home signal for the old CD tower crossovers. The signal was flashing green to double red back to green. I am used to the solid double red and the flashing green for these signals. This was this first time I saw them do this. Was this a malfunction or is this a special signal indication. Thanks in advance.

  by ClearFromBerkToHill
 
The signal you saw was something called an "absolute block" signal. This typically refers to a cab signal failure. Normal operating procedure would be to contact RTC (depending on your district on the Hudson), proceed at slow speed until clear of interlocking limits, and be prepared to stop at next signal.

  by DutchRailnut
 
The signal indication is used for both trains finishing a run after cab signal fails or if a shoving move is being made. It signifies the block from that signal to next interlocking is clear and free of trains.

  by ClearFromBerkToHill
 
Correct, good points.

My experience with absolute block is that they are usually simple errors at RTC, not genuine conditions that call for an absolute block. So, I always radio in with a nosy comment, though this is probably wrong of me.

  by harmon44
 
Just a follow up. A train passing this indication is restricted to slow speed until the next signal? Thanks again

  by ClearFromBerkToHill
 
Correct.

"Trains or engines without operative cab signals proceed at Slow Speed within interlocking limits, then proceed not exceeding 40 MPH..." blah, blah, blah

So, yes.

PS: When you saw this signal aspect, were you looking out the head-end window and this signal was on your track? If this signal was on a surrounding track, it would have no impact on your train.

  by harmon44
 
I saw the signal as I was driving to work on Rt. 9. It caught my attention because I had never seen that indication before. I have occasion to be near all the lines when working, and have many times seen the signals prior to the ineterlockings, but never saw that aspect displayed. Thank you both for the education.

  by MNRR_RTC
 
ClearFromBerkToHill wrote:Correct, good points.

My experience with absolute block is that they are usually simple errors at RTC, not genuine conditions that call for an absolute block. So, I always radio in with a nosy comment, though this is probably wrong of me.
I use the ABS to get the attetion of trains when they don't answer the radio and I need to contact them. It works very well at getting their attention. :-D

  by Clean Cab
 
Then we engineers call the RTC after our hearts start beating again!!! :)

  by Swedish Meatball
 
ClearfromBerktoHill, You may have an out of date Operations Manual the MAS is now 59 mph with an absolute block signal.

  by Maybrook fan
 
As long as this thread is asking signal questions I have one I always wondered about.

I was always told Metro north used cab signals that appeared on the enginers panel. If this is the case then why on the Harlem line (not familular with others enough to include them) why are there light signals from Wasaic to GCT ????? Do they actually have 2 signal systems on this line ????

This enquiering mind would like to know :)

  by pgengler
 
Maybrook fan wrote:As long as this thread is asking signal questions I have one I always wondered about.

I was always told Metro north used cab signals that appeared on the enginers panel. If this is the case then why on the Harlem line (not familular with others enough to include them) why are there light signals from Wasaic to GCT ????? Do they actually have 2 signal systems on this line ????

This enquiering mind would like to know :)
Wayside signals are typically present on cab-signalled lines as a backup measure; that way, in the event of a cab signal failure, trains can still operate on signal authority, without having to continually obtain movement permission from the dispatcher. It would also allow for the movement of non-cab-signalled equipment, though cab signals may still be required in the lead unit.

  by Clean Cab
 
Actually MNRR uses wayside signals that don't really convey any aspects other than STOP, PROCEED CAB and ABSOLUTE BLOCK. The aspect diplay unit (ADU) on board all MN trains shows NORMAL (maximun authorized speed) LIMITED (45 mph passenger, 25 mph frieght), MEDIUM (30 mph passenger, 15 mph frieght) and RESTRICTED (15 mph passenger and freight).

MN is considering a 5th cab signal aspect that would govern high speed (60 mph) switches. There are quite a few high speed swicthes that the train will have a NORMAL cab signal indication on the Harlem and New Haven lines.
  by Head-end View
 
Hmmmm..............With the present system how does a M-N engineer know to reduce speed for a crossover thru a 60 MPH switch? LIRR has more cab-signal aspects. Their indicator will drop from 80 to a 60 code when approaching a "high-speed" crossover.

  by MNRR_RTC
 
The Timetable special instructions tell you what speed limits are in effect for a particular segment of railroad on a particular line. This is why engineers, conductors and RTC's must be qualified on the physical characteristics of the the sections they work in.