Sam's Steel Rails West

Mechanics Corner June, 98

Locomotive Safety Devices

History:

In the 50's and 60's a feature called the Dead Mans Petal were being installed on Diesel Locomotives. It was a good idea except for one thing; It was easy to nullify.

This feature comprised of a spring mounted pedal that sat on the floor where the Engineer sat, and in theory if something happened to the Engineer the spring tension on the pedal would lift up and through an air valve would automatically set the Automatic Brakes on the train. If everything operated properly it would work, but too many crews couldn't be bothered with this device, and more often than not a cast iron Brake shoe or a packing hook would keep the pedal in the down position all the time, nullifying this safety device.

Later on, I'm not sure when, different Railroads used the Alerter. A lot more safer and fool proof device. The Alerter worked on a system, where when the Brakes were released, it would set off several types of warnings every few seconds. The alerter would reset if the throttle, brake, and on some early applications if the Engineer would move in his seat, or if he touched metal, grounding himself. Todays alerter doesn't have a sensor in the seat, but will respond if the Engineer moves the throttle or Brakes or otherwise acknowledges through a button on the control stand. He has to do one of these things every few seconds, or first a Bright light flashes, then if he still doesn't move or acknowledge, a loud chirp or siren wales in the cab, then if he still doesn't acknowledge a penalty Brake application is set Automatically. He then has to Move the Automatic Brake to recover the Penalty.

ATS or ATC: Most Railroads have some kind of Automatic Train Stop equipment of one kind or another. Most work on the principle of a magnetic pick up shoe mounted under the front or to the side of the locomotive and is energized when the loco goes over a mounted plate along or between the rails. These Plates are located anywhere there is a sharp curve or dangereous situation where speed has to be reduced. Like the Alerter above the Engineer has to acknowledge by a button in the Cab or a Brake application will result. Their are atleast 6 different styles similiar in design. I wonder why they dont standardize so only one type of system is used.

Overspeed: A system that if the maximum speed is exceeded it sets the brakes automatically. The speed is preset according to the railroad.

The Future: Satelite Communication is the future, and Modern day trains are tracked by Satelite using a system and train crews can communicate through these systems. Someday you will probably see crewless trains ran by these Satelite Systems.