January 29, 2011

Guard Rail! Why didn't I think of that?

Bill Uffelman, an experienced O Scale modeler from Nevada, visited the layout this weekend. He is currently doing an On30 scale project.  After a brief introduction to the railroad, I handed him a throttle and asked him to take a train from staging in Aquia Landing to Falmouth. Then turn the engine on the turntable and bring the train back, while dropping a boxcar at Potomac Creek siding.  Having a background in  operational testing, I figured that having an experienced operator run the layout could would be a good way to find glitches. And find them we did.

I had mentioned earlier that humidity changes were causing some track problems resulting in intermittent derailments. One spot where this was happening was in the curve just before the first turnout at Falmouth. This track had been problem free up to now. A gauge check showed some tightness in the gauge. I respiked some of the rail back to gauge standards.

I also had a known issue with the Whiton locomotive at the north end of Potomac Creek bridge. The other locos and cars did not have a problem here. The Whiton's lead truck derailed about half of the time as the train moved north. We went through possible causes, first checking the wheel gauge, which seemed a tad tight on one axle. Then I checked the track gauge, which was OK, but there appeared to be a very slight kink in the curve. There also was a dip in the outside rail. I shimmed the rail and smoothed out the easement. A couple more tests showed that the problem was better, but still was there. At that point Bill suggested a guard rail. That was a great suggestion. I installed a guard rail and ran more tests. The derailments are gone. I made a video showing how it works.



His work done, Bill left. But, using the same logic, I added a guard rail to the problem curve at Falmouth after also checking and adjusting the gauge. This seems to help. Lest you accuse me of using a unrealistic crutch, my ridiculously tight curves would probably require a guard rail in the prototype too. For example. look at the guard rails in the USMRR Alexandria yard. File that in "there's a prototype for everything."
Guard rails used to keep wheels from derailing on a curve at the USMRR Alexandria yard. Note
 the three way turnouts at the lower and upper right.

4 comments:

  1. Is the guard rail on left on the out side of the running rail?

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  2. I was thinking that too. What's that all about?

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  3. I don't know for sure. Maybe they realigned a rail or are getting ready to replace it.

    ReplyDelete