1948 New York Central signalling movie

Cool!!

That's an interesting period piece. I wonder who was the intended audience ... school classrooms?

I grew up next to the New York Central main line and there was a big signal bridge behind our house. There were three searchlight signals vertically arranged over each main track for each direction. I never figured out the full range of different signal indications. The signal lights were approach lit, not on all the time.

When I revisited the place in 2011, the same signal bridge now has two lights for each track in each direction. I know how that works. Can someone explain the indications for the three-light arrangement? The 1948 video didn't cover it.

East of East Rochester

What a great film that was!   What is shown at 1:37 appears to have been part of the show the Association of American Railroads put on at the 1939 World's Fair.  What I find of interest is that, even though this was released in 1948, no diesels are shown.  Possibly a majority of the scenes used were taken before the war. The background music was done by a full orchestra and is fun to listen to. These short films undoubtedly were made to be shown in theatres back in the day to show the public how innovative and safety conscious they were.   The American railroads produced numerous films of this nature as late as the 1950's.   They are easy to find on You Tube.  Thanks for posting that gem.  

I believe most if not all three light signals where only at Interlockers,  The color combinations where to indicate the route being taken and the condition of the block ahead. Like if it was occupied...

Marty

Although NS is actively phasing them out, the PRR position light signal passed its 100th birthday in 2015.

George

>What I find of interest is that, even though this was released in 1948, no diesels are shown. 

You must have nodded off at 4:30, 9:30, 15:04, and 16:47 

>signal bridge now has two lights for each track in each direction. I know how that works. Can someone explain the indications for the three-light arrangement? The 1948 video didn't cover it.

Here are the answers...     NYC signal rules

General NYC signals from the Big Four Lines (CCC&StL) of the NYC.

General meanings of RR signal system.

Wyhog

Wyhog posted:

>What I find of interest is that, even though this was released in 1948, no diesels are shown. 

You must have nodded off at 4:30, 9:30, 15:04, and 16:47 

You are correct.   Thanks for pointing that out.  

Wyhog posted:

>signal bridge now has two lights for each track in each direction. I know how that works. Can someone explain the indications for the three-light arrangement? The 1948 video didn't cover it.

Here are the answers...     NYC signal rules

General NYC signals from the Big Four Lines (CCC&StL) of the NYC.

General meanings of RR signal system.

Wyhog  

Thanks for the link, I'll look that over. Since NYC was a high-speed multi-track route they had more than the usual number of signal indications. NYC's 1957 CTC installation generally allowed bi-directional running on both main tracks with crossovers at regular intervals. I recall these three-head signals were used at many places on the main line.

http://railtek.byethost24.com/...nals/signals.htm?i=1

This first diagram shows a typical 3 head color light signal. The key is in understanding that each head governs a specific speed route. The higher on the pole the higher the permitted speed.

• The top head governs the HIGH speed route. This would be "straight ahead". Not diverging through any switches. Track speeds would typically be greater than 45 mph and may be over one hundred mph.
• The middle head governs the MEDIUM speed route. It would typically be used when diverging through relatively long track switches which are designed for speeds in the 30 mph range.
• The bottom head governs movement on the SLOW speed route. That would be diverging through shorter switches that are only safe to traverse at 15 mph or slower.

This confirms what I thought I remembered, that some indications had flashing lights:

Flashing a light on a signal "upgrades" that signal to a less restrictive signal than it would otherwise be if the light were not flashing.

 http://www.railfanguides.us/ny/depew/

The picture of the ex-NYC signal bridge with the CSX freight passing it has something interesting.  It looks as if the bridge covered FOUR tracks.  With the deduction of tracks and passenger service, the remaining signals went from 3 heads to two.

Dominic Mazoch posted:

The picture of the ex-NYC signal bridge with the CSX freight passing it has something interesting.  It looks as if the bridge covered FOUR tracks.  With the deduction of tracks and passenger service, the remaining signals went from 3 heads to two.

Yes, it was four tracks until CTC was installed in 1957. Then it was cut to the two main tracks seen here, the #3 track was removed and the #4 track (far left) was retained for local service between East Rochester and Fairport at least through 1998. There were crossovers between all three tracks in the vicinity. I lived next to these tracks up to 1968 and this signal bridge still had three-head signals up to that time, and possibly for another 20+ years after. 

I'm a bit late with my response but let me add my thanks to John for posting this very interesting video.  I had been planning on asking the forumites about the wire shown below that I photographed on some NYNH&Hartford/Penn Central track in West Concord, MA.  It reminds me of what I remember of our childhood S gauge American Flyer layout with jumper wires soldered here and there.

Just prior to 4:05, the NYC video explained these wires and automatic block signals and that electricity passed through the track.  They also showed the facility that generated the electricity.  But, I'm confused.  Does a low level of electricity always pass through the track?  If not, how is the application of or removal of electricity coordinated with the train presumably completing or breaking the circuit that fires the signals?  (Did that jumbled sentence make any sense?)

Thanks,

Tomlinson Run Railroad

TomlinsonRunRR posted:

...  Does a low level of electricity always pass through the track?  If not, how is the application of or removal of electricity coordinated with the train presumably completing or breaking the circuit that fires the signals? ...

https://en.wikipedia.org/wiki/Track_circuit

Basically, low voltage battery power is applied to the running rails and the signalling circuitry detects the voltage and energizes a relay. When a train is on the track the voltage across the rails drops to essentially zero and the relay drops out, activating signals. Bonding wires across rail joints were commonly used to provide good continuity for the signalling system.

Ace, thanks for your very succinct and clear explanation. The wikipedia article was interesting, especially the part about the use of different AC frequencies. I hope to walk those 1915-era rails again looking for signs of where the original blocks were. (It's destined for a rail trail soon.)

Regards,

Tomlinson Run Railroad