A blog devoted to explaining the ins and outs of North American railroad signaling, past, present and future. This blog seeks to preserve through photo documentation the great diversity and technical ingenuity of 20th century signaling and interlocking hardware and technology. Related topics cover interlocking towers and railroad communications infrastructure.
Note, due to a web hosting failure some of the photos and links may be unavailable.
Sunday, December 2, 2018
Caught on Camera: ATS Ding
Intermittent Inductive Automatic Train Stop (ATS) was that thing that met the minimum safety requirements for high speed rail as laid down by the Interstate Commerce Commission in 1948, and although adopted by the New York Central, Southern, Santa Fe and others, was pretty much ripped out everywhere it could be after the end of most private passenger operations in 1971. ATS soldiers on in those few places where it could not be so easily discarded, namely the former Santa Fe transcontinental Southwest Chief and San Diego routes and the former Chicago Northwestern commuter lines out of Chicago. The latter two routes both feature bi-level cab cars where one can, in various degrees, get a railfan view and hear the going on in the cab, so it becomes possible for one to hear just what sort of alerts this safety alertness system produces.
METRA Up-NW Line Typical ATS Inductor Setup
Now I was expecting something similar to a British AWS activation horn, which is quite loud and designed to get the operator's attention. However, when I reviewed my video, what I heard in METRA Gallery cab cars was small analogue bell chiming once. You might even need to replay the video a few times as you might miss it right after the train passes the Diverging Clear signal.
In this Amtrak Surfliner video you can hear a small electronic beep right after the passes a diverging signal at T=11:20 and an Approach Diverging Signal at T=6:55. Again, very underwhelming.
These are just two examples of videos where one can hear the ATS ding, but they cover both types of equipment passengers can reasonably expect to hear a ATS activation from. I may post updates here if I find cab videos from other equipment.
First, a pedantic one – the railroad's name is Chicago & North Western (not Northwestern).
Second, on the old North Western cab cars, there was a short horn that sounded until the acknowledging lever was actuated. I think the "ding" came in with the Metra rolling stock.
Third, when was the top photo taken? The image is of the signals just east of the Dee Road station. The opposite side of the signal bridge had Type E (horizontal color light) signals until fairly recently. (I grew up in the suburb of Park Ridge where this scene was shot.)
Fourth, I'll share what I hope is an interesting operational tidbit. By rule, the ATS system must be cut in on the engine of northbound trains leaving Chicago Passenger Terminal. Once cut in, the key (referred to as the "ATS token") is removed from the lock, and is handed to the conductor to be held in his possession for the remainder of the trip.
Returning southward, the process is repeated at the outer terminal. When the train reaches the end of ATS territory at Bridge "K" at Erie interlocking, the conductor hands the ATS token for the leading cab car back to the engineer through a receptacle in the cab car for that purpose; the engineer can then cut out the ATS coming into the terminal.
When I was a teenager traveling in the old C&NW cab cars with crews that I knew, the conductor would often hand me the key as we left Clybourn, knowing that I would do what needed to be done when the engineer cracked his door open to reach for the token.
Thanks for the information. Thinking back I would notice conductors heading up to the head end of the gallery cars, but I never thought much of it. I'll def try and document that next time I am on that line.
The photos of the signal were taken on Nov 30th, 2018. I guess they recently went about replacing all of the horizontal signals. I hadn't even considered trying to document them and now I am a bit annoyed with myself I didn't do this route a year or two earlier.
I've got a couple of comments, Mike.
ReplyDeleteFirst, a pedantic one – the railroad's name is Chicago & North Western (not Northwestern).
Second, on the old North Western cab cars, there was a short horn that sounded until the acknowledging lever was actuated. I think the "ding" came in with the Metra rolling stock.
Third, when was the top photo taken? The image is of the signals just east of the Dee Road station. The opposite side of the signal bridge had Type E (horizontal color light) signals until fairly recently. (I grew up in the suburb of Park Ridge where this scene was shot.)
Fourth, I'll share what I hope is an interesting operational tidbit. By rule, the ATS system must be cut in on the engine of northbound trains leaving Chicago Passenger Terminal. Once cut in, the key (referred to as the "ATS token") is removed from the lock, and is handed to the conductor to be held in his possession for the remainder of the trip.
Returning southward, the process is repeated at the outer terminal. When the train reaches the end of ATS territory at Bridge "K" at Erie interlocking, the conductor hands the ATS token for the leading cab car back to the engineer through a receptacle in the cab car for that purpose; the engineer can then cut out the ATS coming into the terminal.
When I was a teenager traveling in the old C&NW cab cars with crews that I knew, the conductor would often hand me the key as we left Clybourn, knowing that I would do what needed to be done when the engineer cracked his door open to reach for the token.
Thanks for the information. Thinking back I would notice conductors heading up to the head end of the gallery cars, but I never thought much of it. I'll def try and document that next time I am on that line.
DeleteThe photos of the signal were taken on Nov 30th, 2018. I guess they recently went about replacing all of the horizontal signals. I hadn't even considered trying to document them and now I am a bit annoyed with myself I didn't do this route a year or two earlier.