To this point, the photos I’ve seen of early SP diesels appear to show Nathan horns. As I haven’t seen any closeups or shots from above, what I can’t distinguish is whether they were 3 or 5 chimers. I’m also presuming that it’s the largest of the horns that faces forward.
John
Oops, forgot an important item: GP9s and SD9s.
A popular upgrade was the Nathan 5 chime, 3 forward - 2 back or 4 forward-1 back and several Alco PA’s assigned to Coast Line passenger service were retrofitted with Typhoon horns salvaged from scrapped GS series engines for additional variety .
Dave
Southern Pacific Historic Diesels volume 4 SD-7’s and SD-9. All the photos I see show 3 chime horns. Both the early 7s and 9s all had 3 horns. 2 forward 1 back. Hope this helps. ps …I always loved the sound of the 5 horn Nathans.
The SP Lives On !!!