In anticipation of delivery of seven AEM7’s, SEPTA wanted to test the new locomotives’ burden on its electrical distribution supplying the former Reading electrification. A Sunday, the slowest day for commuter runs was chosen, and Amtrak loaned SEPTA AEM7 923. With a string of five former Reading “Blueliner” MU cars in tow, the electric made its way to Lansdale on the North Penn branch. Here the AEM7 stands on the Doylestown branch as the early 1930’s cars run onto a siding.