Nighttime Train Horn Runbys w/Crazy Echoes

Here's a few train horn recordings I took took back in winter near Duncannon, PA. The valley ridges made for some stellar echoes alongside the NS Pittsburgh line.
All of the horns belong to a friend except the CSX K5LA.

The horns are in order as follows-
-Chessie System Big Bore K5LA. 1977, big tag, cork foot gaskets.Very rare early production. This recording was taken before remachining of the heavily worn power chambers.

-Norfolk Southern RS3L with Tampa power chambers, unknown unit.

-Norfolk Southern round tag K5LA, 39k serial tag. (approximately 2003) from a C40-9W. Has undergone extensive remachining of the power chambers. Originally R24 but was run all bells forward in this recording.

-The same NS Round Tag K5LA shimmed to K5L specs using 3d printed spacers inside the 3a and 4a.

-My tagless transition era K5LA from CSX #2235