One entry in the Special Rules section of the New York Central 1937 Edition RULES FOR THE GOVERNMENT OF THE OPERATING DEPARTMENT book is most interesting.  It is under the fireman’s responsibilities:

Rule 943: If engineman fails to regulate speed of train when approaching a signal indication or other condition requiring that speed be reduced, they must communicate with him at once, and, if necessary, stop the train.

The pressure on enginemen to meet schedule, particularly on the top passenger trains, must have been tremendous.  They were only human and it is a natural tendency in all of us to “cut corners” when under pressure.  When Automatic Block Signalling was introduced, all railroads had an opportunity to increase the traffic density and improve safety on their mainlines.  Improve safety, that is, as long as enginemen followed the operating rules.  “Running on the yellow” was a dangerous practice where an engineman, typically trying to make schedule, would not reduce his high speed to medium under a restrictive (yellow) signal indication.  Worst case, this could result in not having enough distance to stop his train before colliding with the rear end of another ahead.

Here are the ABS signals directly from the book (please note Rule 282, 284 & 285):









Medium speed was 30 mph on the New York Central.  Other speeds were: Limiting (45 mph) and Restricted (15 mph).

In 1922, in response to the number of rear end collisions in ABS territory across the nation, the Interstate Commerce Commission required railroads to implement an automatic train control/automatic train stop (ATS) system.  Implementation would be in stages, by mileage and by deadlines (dates).  There were a number of systems offered.  After some testing, the New York Central chose the intermittent Automatic Train Stop system offered by General Railway Signal Company.  It was robust, simple, and operated in all weather conditions.  It turned out to be a very reliable system.  As it happened, the New York Central installed the GRS ATS on over double the required mileage.  No doubt it was worthwhile.

This is an extremely large topic for a blog, and I wouldn’t do it justice anyway, so for very detailed reading I suggest two very excellent and interesting Central Headlight articles (



These articles can be obtained from the NYCSHS website on their DVD offering of the first forty years of the Central Headlight publications.  This DVD is packed with tons of history, data, photos, prototype info, drawings, and stories.


I will try to summarize the GRS ATS for our purposes….

The system used electro-magnets to detect a lineside signal indication; there were many combinations of course, but for our understanding I’ll simplify it to restrictive (red  or yellow) and clear (green).  Some distance before the signal, a wayside inductor (connected to the signal), was placed outside of the rail on extended ties.  The locomotive tender truck (or a truck on a diesel locomotive) had a matching receiver mounted that read the wayside inductor.  This connected (on the locomotive) to a forestalling lever, the train service brakes, and to a cab mounted whistle (and later to the speed recorder).  Below are pictures from the 1941 Locomotive Cyclopedia.




The control box is the most visible part (to those who know what it is).  It is seen below on the deck, a typical place on NYC steam, of a massive L3a Mohawk tender (15500 Gallons – 43 Tons ! ):



When the train approached a green (clear) signal the engineman simply proceeded through normally at designated track speed.  If the signal was restrictive and the engineman failed to stop, the system would put the train into full service braking (not emergency) and it had to come to a complete halt before it could be reset.

However, to allow the engineman to have full control of his train and to facilitate the operational flexibility of the ABS signalling, railroads were allowed to have a forestalling lever that the engineman would operate to acknowledge yellow indications.  When approaching the yellow signal, he would hold down this cab mounted lever and it would override the ATS system.  When this happened, a whistle in the cab blew to alert the crew that they had forestalled.    The engineman was expected to follow the rules and reduce his speed to medium.  The forestalling lever could only be held down for 15 seconds, so the ATS system could not be defeated for the entire run.

However, there still were accidents involving serious injury and death simply because some enginemen would not reduce to medium speed and be prepared to stop.  This is shocking as these men on passenger trains were the cream of the Railroad, the very best with years of operating experience.  The pressure to make schedule along with knowing the route, knowing the timetable, running as a following section, knowing the engineman ahead, the signalmen along the way, and the normal routine tempted a few to roll the dice at times.

Beginning just before WWII, forestalling was recorded on the paper speed tape as a tick mark.  The speed tapes were reviewed after each run and now they would show wherever an engineman forestalled a yellow and whether or not he reduced his speed.  Finally there was a means of enforcing the operating rules.

This is all interesting history, but what does this mean for Fillmore???