Signals GCT

Yesterday I was riding the train into Grand Central. Just before
we arrived at the platform, we stopped at signal X S
It was Red over Red
after a train left the platform
the signal changed to red over flashing yellow
and the train proceded in
I searched the forum and found info
about wayside signals however
I was wondering about the aspects of the signals
leaving and entering GCT

First of all, you did not see a red over a red. There is no such signal within GCT. A "Stop Signal" within GCT is a red light over two dark lights. The positive signal you saw was a "Terminal Approach", which means the next signal was a stop signal, or stop sign.

There are only 4 signals in GCT
Red over two dark is stop signal.

Red over yellow is Terminal restricting, meaning next signal is red but block ahead could be occupied

Red over blinking Yellow is Terminal Aproach , prepare to stop at next signal

Red over solid Green , Terminal proceed , next signal currently displays better than terminal stop or restricting.

The speed in GCT is same for all signals (but terminal stop) the speed is 10 mph max.

Thanks for the info
I must have remembered the first signal wrong

Once you are within GCT limits do these signals over rule the cab signal ??

The cab signal will always display a "Restricted Cab" aspect in GCT. Since the indication for Restricted Cab is to "proceed at restricted speed," the wayside signal provides additional information. It doesn't override the cab signal, it complements it.

Jim

So outbound from GCT, at what point does the Cab Signal start upgrading from Restricted? Is it after passing CP1 going out bound? Also for inbound trains, at what point do the Terminal signals take over and the cab is at Restricted?
Patrick

Northbound the aspect picks up to medium cab at start of tunnel just before 59 street emergency platform, the speed does not actually change from 10 mph till entile train has cleared CP1.

Southbout the 10 MPH starts at the North end of CP1 all way to block.

Northbound, cab signals upgrade (when appropriate) at 59th Street (exiting from CP 1). Southbound, the first GCT interlocking signals are at the end of the 4 main tracks, immediately north of where Tower U (the building, not the interlocking) is.

Jim

So the signals do not indicate routing through the interlockings, only the condition of the track ahead?

correct, its up to engineer to check routing.

and the routing with the double Swiches and moveable frogs can be interesting

So how does the engineer know which route his train is taking to the platform? Does RTC radio him ahead and give him a platform number?
Patrick

No. Operating rules prohibit an RTC (and tower operators on other railroads) from telling a train engineer the route they will take, unless they're being given verbal permission to pass a signal in the stop position. It is the engineer's responsibility to know where each switch leads, and if it's going to a place where his train shouldn't go, he stops his train and calls for instructions. The engineer normally finds out what track he's platforming on in GCT at some point along the way when no other route is possible, given his current location and the position of any switches ahead.

Practically speaking, most trains platform on the same track every day, so if an engineer is routinely on the same run each day, he knows where he'll probably end up. But he's not told what route he'll take to get there, and there are several ways in to each platform.

Jim

As engineer i do not really care what platform i go to, as long as its a platform track and as long as I know it will fit my train.

If I run a deadhead I really do not care where they send me, any track will do, but again as long as my train fits.