I haven’t found it yet, but I recall a BN engineer citing to me an early Federal rule that once required bi-directional locomotives to have a horn pointed for each direction of travel. I believe this only applied to mainline service locos and switchers were exempt, plus steam locos were not included since a whistle is omnidirectional.
A look at early diesel photos of all types show single horns arranged this way, many with single-bell horns placed on the hood roof in different positions or on the sides of the long hood, and not always being on the cab roof. Since the bell trumpets directionally, they were not required to be mounted on either end, just pointed in either direction. Of the BN, ATSF, KCS and SP EMD cabs I’ve been in with single, directional horns still in place with a pull-cord, the horn ropes usually came down from the roof (sometimes on pulleys) and were tied to the top of the classic EMD ‘barrel’ controller where the throttle, reverser and transition levers were. They were set apart by several inches and had wooden or metal handles near the end where they were attached. Usually only one horn was blown at a time-using the one for the direction you were travelling in, but I’ve watched some Old Heads grab both horn ropes above the handles and haul back blowing both horns at once for a different sound-and just to be different. Even though both single-bell horns may be turned to the same note, over time the pitches would change slightly, and blowing two at the same time gave a fuller, different sound. Trying that with a horn that needed maintenance or had drifted way off tune could produce a shrill and unique shriek. I didn’t see many guys do that since it required more effort to pull two cords instead of one.
Some railroads did move the rear-blowing horn further down the hood, away from the cab, like some ATSF GP7’s with the rear bell mounted near the center of the long hood near the exhaust stacks. Some MKT SD40-2’s has a single bell horn mounted near the rear sand hatch, while a multi-chime Leslie sat on the roof pointed forward. I believe an air valve switched between the two horns depending on the reverser position for the lever-operated horn. At some point the rear-pointing requirement was annulled.
-Tom
From: CBQ@groups.io [mailto:CBQ@groups.io] On Behalf Of spsalso via groups.io
Sent: Wednesday, November 27, 2024 1:32 PM
To: CBQ@groups.io
Subject: Re: [CBQ] Train Horn - Was types of gallery cars
While the "second horn" COULD have been connected to be activated along with the main horn, it seems pointless to me.
And, facing forward, it could hardly be called the "rearward" facing horn, as on BN 732:
So my completely uninformed guess/opinion is that the second horn was used as a special signal for other Q/BN employees, NOT as a grade crossing warning.
My other completely uninformed guess/opinion is that it was installed based on a request by a city/town that the train passed through, likely as some sort of "quiet" horn.
Don't have a third uninformed guess/opinion at the moment.