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Making a AF Dwarf Signal by Ben Swope

April 11th, 2015 · No Comments

As intending to signal a large single track loop for multiple train operation, I wanted to keep the layout pure American Flyer, so the obvious choice is to use AF’s # 761 semaphores. To keep the six signaled controlled blocks at an even length, one signal is required to be placed in a long hidden section under benchwork. Here the overhead restriction would be too low for these tall semaphore signals, standing 9-inches tall with the blade in the “clear” position.

The solution to this problem came in the form of a train show junk box find, were a # 761 semaphore was purchased so cheaply, experiments could be made without concern if the signal was destroyed in the process. However the first attempt at modification resulted in such a success, I thought other AF enthusiasts would be interested, and perhaps offer another signal option for use on your own pike.

This junk box purchased operate quite well, though it was not in perfect appearance, and had a few parts missing. This made it a good candidate to convert to a dwarf signal, yet once modified would operate identical to standard versions.

Start the modification by removing the semaphore blade, ladder, bulb socket, finial from atop the mast, and the coil & blade activation rod assembly from the base. At this point all you’ll have is the base casting, the signal head casting, both connected only by the hollow mast tube.

Using a small punch and hammer, carefully drive the mast tube out of the base from inside of the base casting. Work the punch around the tube’s end to avoid cocking the tube within the casting, as damage the base structure may result.

Once removed, measure and mark the mast tube 1-inch from the bottom of the signal head and cut the mast tube off squarely (I used a common hacksaw). De-burr and true-up the ragged cut to prepare resetting it back into the base casting. If done correctly, a few taps on the top of the signal head (using a block of wood to protect the signal head casting from the hammer blows) will set the mast back into the base casting. If necessary, some glue may be used to secure this connection. Ensure the signal head is located in its original orientation to the base.

This process should make the now exposed distance from the mast tube of the base structure to the bottom of the signal head about ¾-inch. This is about as short you’d want to allow for easy removal/insertion of the bulb and socket assembly.

Next is the activation rod modification (the rod that rides inside the tube). Place the coil and activation rod assembly back into the base and fasten with the original screws. Of course, this rod will now extend far out the top of the mast and signal head at this point. Push and pull the rod to its extreme motions while sighting through the signal head. Observe the rod’s end movements though this crescent shaped hole and mark its end strokes with a small felt-tip marker.

Remove the coil and rod assembly again. Note the marks on the rod and find the middle of the extreme motion marks. Remark this point with a different color marker (or score with a file, etc.), and replace the assembly to check the center marked point prior to drilling. Pear again in the signal head hole to double check its location as being the best point to drill a new hole for the signal blade pin hole and thus rotate the signal blade correctly.

Once satisfied of the location, remove the coil/rod assembly once more and drill a new hole sized for the pin that rotates the blade and de-burr. Follow this by cutting the rod to length just above the newly drilled hole and de-burr.

For my dwarf signal, I chose to shorten the signal blade as well; removing about ¼-inch off the fish-tailed end. At this point, it’s your choice to make this cut flush, recreate a fish-tail end or simply not shorten the blade.

Lastly, I chose not to replace the finial atop the signal head (as with a shortened signal blade, it looked too “busy”). I instead modified an old AF freight car truck rivet, and with contact cement, placed it in the same hole the filial once was, acting as a button cap to keep dust out.

This signal, once reduced in height, looks to have been an item Gilbert would have produced and advertised as a working dwarf signal, perhaps used in conjunction with power switches at the end of a passing siding, branch line junction or yard lead.

This entire modification took about two hours to figure out and perform. With these simple instructions, your time may be less. If you choose to do the same, your efforts will yield an interesting new addition to the many American Flyer accessories on your layout.

Ben Swope

Tags: Main Line

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