
EMD SD60 Roof Detail
What is the device in the forward center of the roof?

What is the device in the forward center of the roof?
I’ve had a problem for two years that I just solved. I use my test track on my bench for testing both DC and DCC locomotives. To switch, I have to move my power pack and change some wires around to hook up my LokSound programmer.
To solve this problem, I designed a control panel and electrics to create an integrated solution. Just finished it up. Works like planned.
I’m trying to design a 12v circuit for a model train test track. I’m confused as to the reversing toggle switch on the bottom, which is used to change track direction. Looks to me that it will cause a short when flipped. What am I missing? I apologize in advance for my non-standard nomenclature. I’m not smart enough for EE. Thanks.