Wednesday, December 28, 2011

Prototype Railroading: FRED

Occasionally I get asked why trains no longer use cabooses.  The caboose used to be the Conductor's office.  Many years ago, a Conductor was assigned a caboose, and they usually personalized it a little, since it was their home away from home.  They had a desk, bathroom, small cooking area, and either stove or electric heat.  Usually they had a seating arrangement that gave the Conductor a good view of the train ahead, either from a cupola or a bay window.  Part of the Conductor's duties was, and still is, to monitor the train for any obvious defects.  One that would be pretty easily spotted from the caboose would be an overheated journal bearing, which often generates smoke.  Additionally, the Conductor had a brake valve and air pressure gauge on the caboose, and could slow the train down or stop it if necessary.  A Brakeman rode the caboose with the Conductor, and when the train had to enter or exit a siding, one of them would line the switch to its normal position, behind the train.  A Brakeman also rode in the locomotive, with the Engineer, and he would line the switch for the train to enter or exit the siding.  In the late 1980'2 and early 1990's, the caboose began to disappear, and they were replaced by a comparatively small, and cheaper device called, rather boringly, an "End of Train Device," or sometimes called a "FRED," which stands for a variety o things, depending who you ask.  The "F" varies from "flashing," to a number of obscenities, depending who you ask, followed by "Red End Device."

An End of Train Device is a small, usually orange or yellow, box, which mounts on the rear coupler of a train, and does almost everything the Conductor used to do on a caboose.  It couples to the air hose at the rear end, and monitors the air brake pipe pressure.  It also sends a readout of that pressure up to a device on the locomotive, called the "Head of Train Device," and often called "Mary," around here.  The engineer can look at Mary and see what the pressure on Fred is.  The FRED also lets Mary know when the end of the train is moving, which helps the engineer with train handling.  On the Mary there is a switch which allows the engineer to dump all the air on the rear end of the train.  When that switch is activated, the FRED opens a valve and allows all the brake pipe pressure to exhaust, putting the train in emergency braking.  This is desirable in an emergency, because allowing the pressure to exhaust out of the FRED, at the rear, and out of the brake valve, in the locomotive, means the train goes into emergency faster and therefore stops in less space.

FRED's in the Glendive depot.
Photo by James Ogden.
There are a few things FRED cannot do.  The FRED cannot line switches behind the train, and it cannot monitor the train for any obvious defects.  In order to satisfy both those requirements, defect detectors have been installed about every 25 miles, which monitor passing trains for any defects.  They check the temperature of all the journal bearings on the train, and if one is hot, they report exactly which one and which side of the train it is on.  They also check for dragging equipment, and again, they report exactly where it is of any is found.  There are also detectors that can determine if a train is too wide of tall for a bridge, tunnel, or other structure, and detectors that can check for shifted loads, which could potentially cause a problem.  In order for switches to be lined properly, in many places automatic interlockings were installed.  When the train needs to enter a siding, they stop and the Conductor gets off an pushes a button.  The switch then lines into the siding, and when it detects that the train no longer occupies the switch, it automatically lines it back to the normal route.  In other locations, Centralized Traffic Control is in effect, and the dispatcher can line switches with the mere click of a mouse, sometimes thousands of miles away.  Some locations still have hand lined switches, and in those places, the Conductor simply has to walk back up to the front of the train, unless the dispatcher relieves the crew of the requirement to line the switch to its normal position.

When the caboose was removed from trains, jobs were eliminated.  The railroad cut a Brakeman position from all trains, and eventually, the removed Brakemen from road service completely.  Only occasionally are Brakemen still used in road service, and they are primarily used on work trains and when a lot of switching must be done.  The railroad also no longer needs to pay to maintain cabooses.  It is cheaper to maintain a 40 pound orange box than it is a caboose.  Early FRED's were all battery powered.  The battery life was indicated on the Mary, and when it got low, the battery was changed at the next terminal.  If the battery died, the train was limited in speed.  Battery powered FRED's are still around, but now air powered FRED's are more common.  They have a turbine inside them, and a little of the air pressure from the brake pipe is used to spin the turbine and keep the battery charged.  They very rarely die.

Some cabooses are still around, but the railroad mainly keeps them for unusual circumstances.  They get used on work trains and locals periodically, and they are used as a place for the Conductor to stand when shoving a long distance.  Most of them have been stripped of all their equipment, and are little more than a steel box with a couple of old, lumpy chairs inside.  For the most part though, FRED takes care of almost everything at the rear end of the train, and there is no need to have people riding back there anymore.

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