• Hump Yards and Retarder Questions???

  • General discussion about railroad operations, related facilities, maps, and other resources.
General discussion about railroad operations, related facilities, maps, and other resources.

Moderator: Robert Paniagua

  by gazbacho
I'm trying to learn about hump yards and in particular, Retarders. I just joined the forums because my curiosity it sparked and you guys seem like the smart ones when it comes to railroads. I have a few questions if you guys can help me.
1. How widespread is the usage of retarders in hump yards? How many are usually used, and with what frequency and or pattern?

2. How expensive are these things? I realize there are a few different types of retarders but what is a normal price for these that railroads are paying for them?

3. Are these retarders typically stand-alone systems, or do they have to be constantly monitored and adjusted? Do they have to be controlled at all times for each different car load or can some just be left as-is to do their job?

thanks for any info you guys have, it's appreciated

  by clearblock
Here are a few simple answers to a complicated question:

Retarders are essential to hump yard operation to control the speed of the humped cars. Prior to the introduction of retarders, a brakeman had to ride the cars and control speed with the handbrake.

A typical hump will have master retarders located below the crest of the hump and group retarders on the tracks for each group of classification tracks. Some systems also use a retarder on each classification track with or without the group retarders.

Modern retarder systems are computer controlled with automatic speed monitoring and control but under the supervision of a hump operator. Car route selection may also be computer controlled.

The retarding action required by each car varies with the car weight, type of car, wind & temperature, etc so the computer and sensors are constantly adjusting the retarder action.

  by gazbacho
thanks for your help on the matter. so basically no retarder can operate on its own and they all have to be individually manipulated by a controller?

  by LCJ
There are what are known as "inert" retarders. These are often placed at the opposite end of classification tracks from the hump itself. They are designed to keep cars from running out of the tracks after being "humped" or switched into the tracks. Inert retarders are not controlled by anyone -- they just squeeze against the railcar wheels with spring pressure to resist movement through them.

Read this excellent article for more info about hump operations and retarders:

http://www.railroad.net/articles/column ... 021031.php

  by gazbacho
very helpful, thanks a lot!