Tri-light dwarf signals

[jward]

Thank you. That certainly helps. 

 

[Overmod]

Introduction with some explanation of the head design:

https://www.jonroma.net/media/signaling/railway-signaling/1941/Centralized%20Traffic%20Control%20Installed%20on%20the%20Missouri%20Pacific.pdf

[jward]

I am looking for information, diagrams and photos of the unique tri-light dwarf signals used on Missouri Pacific. The ones I am talking about had the lights arranged in an upside down triangle, the opposite if the tri-light high signals that many roads used. Were these commonly used system wide? Were they used by anybidy else? What locations were they used in? Photos online as well as other documentation on them are scarce. Thanks in advance.