Does it depend on the unit's lineage? BN units would likely use a different horn than a former ATSF unit. And former lease units, second hand units like the batch from CN would also have different horns. There were over 3000 units built, there's gotta be a bunch of variations.
SF used Leslie S-3L's. BN Leslie S-3K's. Sometimes it was hard to tell but some BN locomotives S3K's might have been switchted with Prime 990's. It can be very hard to tell the difference.
Horn types are really rather dependent upon maintenance needs. While the BN generally used the Leslie S3K on its units, there were many other types mixed in. These could have come from other component roads (Frisco, for example used the Leslie RS5T) or perhaps replaced on a foreign road after a failure. In my experience, when a horn fails on a locomotive the item is removed and sent to the workbench for repairs, and the shop guys will bring out another horn from a shelf full of spares. It does not have to be the same type of horn, same color, configuration, etc. It only has to function. In the above example, the failed horn would be repaired in the shop and then probably sit on that same "spare shelf" until needed; there is no requirement for it to return to the original locomotive it was removed from. Obviously with new locomotives there would be a period of time before a failure where, say, all 30 delivered units would share the same type...but this would change over time as failures and repairs occur. For a modeler, the best bet is to rely on photographs of the locomotive in question to get the proper type of horn. George Widener CN Fond du Lac, WI
Charlie, I made it! I also run BNSF HO scale. I was trying to get on and give just a cost saving idea. You can use floor dry as gravel or rip rap or even coal if you paint it. Just use screen or a screen strainer works for me. The smaller the screen the smaller you gravel. And I would like to point out that It has a look of B-19 or lime stone gravel or rocks. Just wanted to pass It on. craftman63
