Shielded Bottom Arms on N&W Semaphores ?

[NW Mailing List]

I should like to respond (sic !) to my own post on this topic... 


After corresponding with some "older and wiser" gentlemen who worked on more railroads and have more experience that I do, it comes to light that other roads which had imposed the Manual Blocking of trains as a second level of protection on top of the Timetable-Train Order method of operation, also had the practice of not displaying a "green board" when there were no Train Orders to be delivered. Instead, they displayed Yellow on the Train Order signal if Form 19 Train Orders were to be delivered, Red if Form 31 Train Orders were to be delivered. and nothing if there were no orders for delivery. This was to prevent the misconstruing of a green on the Train Order signal as giving a "Clear" Manual Block indication. I think this rationale and practice may be the reason why the N&W set up its two arm semaphore MBS/TO signals the way it did. 


In this time period, the N&W was neither very inventive nor very proactive, compared to other railroads, and it certainly wasn't a trend setter. Something like putting up two arm semaphores at train order offices ("telegraph offices" in N&W parlance) most likely resulted from a bad wreck where the obvious cause was the misinterpretation of a clear Train Order board as conveying the condition of the block ahead. It is too bad we don't have the details. 


The question still stands as to when this arrangement went into effect and, indeed, when Manual Block rules were adopted by the N&W. 


Another "open issue" here pertains to the color of the roundels used on the N&W's MBS and TO signals. In the early days of railroading, Red and White (for "Clear") were used almost ubiquitously on American railroads. The manufacture of yellow glass with suitable characteristics (chromaticity, transmissibility &c) to serve for railroad signal purposes did not happen until around 1913-1914, if my memory serves me correctly. And it was not until 1917 that the Train Rules Committee of the American Railroad Association (sic) adopted Green as the proper color for a "Clear" indication, supplanting the long-standing use of White. (It being said, mutatis mutandis, that some roads had been begun using Green in the 1890s.) It would be very interesting to know when the N&W made the transition from Red/White to Red/Yellow/Green... but we'll probably never find the answer. Or again, what colors were used on the N&W's first lower quadrant semaphores , Red + White, or Red + some other color?
  


One who responds to his own List posts surely must be the ultimate soliloquist... talking, indeed, to himself ! 


-- abram burnett 

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