01-20-2010, 10:23 PM
HEP cars are Head End Power cars. They are used to supply electricity to passenger cars that have been converted from steam heat to electric. Locomotives in the GG1 era had steam generators to supply steam to the consist. I imagine it would have been necessary to have HEP cars, then, since they were operated into the 80's and I believe Amtrak would have been making HEP standard by then. The GG1's replacements, the E60CP and AEM7 both had HEP.
-Dave