• Cab Speed signal use

  • General discussion about railroad operations, related facilities, maps, and other resources.
General discussion about railroad operations, related facilities, maps, and other resources.

Moderator: Robert Paniagua

  by RearOfSignal
 
For those railroads operating under NORAC rule 562(Cab signals without intermediate waysides) or the similar, how is the cab speed signal used. I know and understand the signals but want to know when going through and interlocking signal would the home signal show "Clear", "Approach", "Medium Clear" etc. Or would the wayside signal show "Cab Speed" and just let the cab signal indication govern? Is "Cab Speed" only used in high speed crossovers or anywhere else?
  by Jtgshu
 
RearOfSignal wrote:For those railroads operating under NORAC rule 562(Cab signals without intermediate waysides) or the similar, how is the cab speed signal used. I know and understand the signals but want to know when going through and interlocking signal would the home signal show "Clear", "Approach", "Medium Clear" etc. Or would the wayside signal show "Cab Speed" and just let the cab signal indication govern? Is "Cab Speed" only used in high speed crossovers or anywhere else?
Cab speed is generally used for highspeed crossovers, and in 562 territory, when following trains - There can be, and is cab speed signals in regular, ABS/CSS territory as well

Amtrak also uses it for its highspeed Xovers, which are usually 80mph.

When you get a cab speed, the cabs will either allow 80mph, 60mph and sometimes appraoch medium/45mph.

However, in the 562 territory, it gives you a few extra blocks inbetween approach medium and clear when following trains.

Inbetween Newark, NJ and NY, Amtraks 562 signal progression is like this

Clear, Cab Speed 80, CS60, Appraoch Medium, Appraoch, and Restricting. Those extra two CS signals keep the trains moving much faster than just clear/MAS or Appraoch Medium/45mph. Amtrak (and NJT on the Pascack Valley LIne)) uses Approach Limited, Appraoch, etc on the home signals in 562. Its not just cab speed or say Restricting/Stop signal on the home signals. So it helps the engineer know how close he is to the train ahead of him and if his cab signals are conforming.
  by Jersey_Mike
 
I know and understand the signals but want to know when going through and interlocking signal would the home signal show "Clear", "Approach", "Medium Clear" etc. Or would the wayside signal show "Cab Speed" and just let the cab signal indication govern? Is "Cab Speed" only used in high speed crossovers or anywhere else?
Railroads that know what they are doing do the former, SEPTA pulled a Metro North and did the latter on its Reading side re-signaling. It's generally slowed things down because now they have to have preemptive code drops for diverging routes because there's no real signal telling the engineer what to do. Trains w/ failed CSS also have to take interlockings at restricted speed and there have been problems with misroutes.

As was said Amtrak uses Cab Speed for 60 and 80mph high speed turnouts as well as in the high density cab signaling area between HUDSON and A.