Tracking the Light Extra: Unusual Semaphore in an Unexpected Place

Tracking the Light Posts EVERY day!

Every so often, I stumble upon something that flummoxes me.

On St. Patrick’s Day, I was enjoying the evening’s celebrations with some friends at The Full Shilling in Finglas (in north suburban Dublin).

This is a large shop (drinking establishment) with lots of décor characteristic of a Dublin Pub.

On the way to the loo, I looked up and was startled to find a three-position upper quadrant semaphore blade.


‘What’s this? And, what’s it doing here?’

As the author of two books on American signaling, I’m reasonably well versed in semaphore practice. (see: Classic Railroad Signaling; Railroad Signaling. Also see: Barnes & Noble.)

On the surface, it looks a like a standard pattern three-position upper-quadrant semaphore blade, commonly used by many American railways beginning about 1908.

The flat-end red blade with white stripe would have been typically used for an absolute signal that display a full stop in its most restrictive position.

There’s one critical difference with this semaphore blade; it’s a mirror of the signals typically used in the USA.

On most American railways, semaphore blades were oriented to the right, while in British practice (which includes Ireland) they are oriented to the left. (New Haven railroad was an exception).

I would guess that this signal is an adaptation of the American pattern for service in Britain or Ireland. But where did come from? And how did this anomalous signal blade find its way to Finglas, which is not even on a railway line.

At the moment, this stands as one of signaling’s great unsolved mysteries.

Do you know the story behind it?


8 comments on “Tracking the Light Extra: Unusual Semaphore in an Unexpected Place

  1. of course the red and green lenses have been swapped……

  2. Manikandan Venkataramanan on said:

    Ah, thats a new fact, very interesting. However, I was speaking from the seminal volume of Geoff Kichenside and Alan Williams, which I could have sworn, you had quoted in your bibliography in your signaling book (one book led to the other). The man was Arthur Bound and I am sorry it was not Southern, rather GCR, perhaps the influence of Fay?. I couldn’t reproduce it correctly from memory. The man advocated three position semaphore, Automatic Block and I think power signaling also. They were all rejected by the commission

    • Manikandan Venkataramanan on said:

      Now that I browse and recollect, there is a section on Irish signaling as well. The authors say that it was quite ahead sometimes of British practices.

      – VRM

    • I can see now that is topic is going to involve some detailed research. Although I’m generally familiar with Fay, I know relatively little about the particulars of GCR and virtually nothing of its signaling (other than what I’ve inspected around Loughborough on the preserved GCR). Based on Fay’s interest and his management style, it seems consistent that he may have encouraged his underlings to follow up on American signaling advances, but that statement is purely speculative. Thank you for your help! BS

    • Incidentally, I authored my original signaling book 14 years ago, so while many of the basic threads remain active in my head, the specific details (and sources there of) can get a bit hazy. My research materials for the book were unusually extensive, if not comprehensive. BS

  3. Manikandan Venkataramanan on said:

    Oh, Gosh, My bad, it should be, “you can learn about Indian Railways from this site” not from

  4. Manikandan Venkataramanan on said:

    Dear Brian

    Have your wonderful book on North American Railway signaling. In fact the three position upper quadrant semaphores were devised by the British Empire for its colonies based on the recommendations of the signal commission, I think, there was this British Southern Railway guy who favored the American Practice for its safety and was thus considered a heretic in his country. Needless to say it was not adopted in GB, however somehow, it came to be used here in India, it is the exact model as in the picture and when I last visited, it was still doing its sterling service. You will find it in my Facebook Profile Photo if you are interested. ( I am stumped though, the signal commission and the revision of signals was in the 1930’s but Ireland gained independence before that?)

    If you are interested you can learn from Indian railways from this site, of which I am just a small member.

    • Sam Fay, who served briefly as General Manager of the London & South Western Railway (1899-1902) traveled to the USA to study American automatic signaling practice. Fay later became General Manager of the Great Central Railway. BS