Thursday, May 23, 2013


With track laid and permanently affixed at Oakridge, I’ve been in “the Land Down-Under” (with apologies to my Australian and New Zealand readers).  Switch machine installation and wiring have occupied much time.  Most model railroads require a fair bit of time spent with these less-than-glamorous tasks.  For a railroad preparing for signals and Centralized Traffic Control (CTC) as it is built, a bit more time underneath the layout is required.  Troubleshooting the wiring has occupied a particularly frustrating part of that time.

My first bout with troubleshooting was documented in my post on my return to basics of model railroading (, wherein I related my mental block  with the Tortoise wiring pattern.  One positive outcome of that challenge was my return to a basic tool for use during wiring: a continuity checker.  Allan Gartner ( provides sound, advice STRONGLY recommending the use of such a device.  I can only add my “Amen!” to that. 

For much of the Oakridge wiring, I dutifully had a pair of continuity buzzers clipped onto the block bus wires as I wired each track.  That caught a couple of slips on my part.  Unfortunately, I did not ALWAYS have the continuity testers attached, nor had I used them (as recommended!) on my turnouts before I installed them.  The result was totally predictable within Murphy’s Law—shorts popping up in wiring done without the aid of the continuity testers. 

Most of my troubles in Oakridge traced back to the turnouts.  I wore out my first triangular file (probably poor filing technique as well as a LOT of turnouts!) on many of the turnouts used in Oakridge.  As a consequence, I had a number of supposed electrical gaps in the pc board ties that still conducted.  Several of these were in ladders of four or five turnouts, all in one electrical block.  My only viable choice was to pull out the rotary tool and cut/enlarge all gaps.  This eventually cleared each short, but it took a while to convince myself of the need (mental block!).

One “last” short was cleared in a previously “clear” block for the Oakridge Siding.  This block has a single turnout at each end.  Everything was fine until I hooked up the frog wires.  I neglected to attach my continuity tester during this operation (The block was clear already, wasn’t it?), so “Murphy” raised his head again and promptly produced a short.  It took a couple of days of tracing the wiring, staring at the switches and cutting some gaps before I finally went back to basics—remove the last thing I did before the short showed up.  I removed the frog wires from the terminal strip.  Sure enough, there it was—the frog ties had not been gapped properly.  The pair of pictures below illustrate this tale.

Oakridge Siding East Switch with continuity tester attached.

Oakridge Siding East Switch frog close up with new, deeper gaps cut in printed circuit board ties.

No comments:

Post a Comment