a few questions for kato gs-4 owners.

[peteski]

What surprises me about these melt-downs is that the circuit breaker doesn't trip when that much current is flowing.
On an old-fashioned "power pack" with the typical slow-acting thermal breaker, it can take 30 seconds or more
before that darn thing trips.   But I would have thought DCC boosters would trip almost instantly.

In my experience most of these meltdowns happen on DC layouts.  But even with DCC, I suspect that some people have the trip current adjusted high enough (and the wiring/track resistance is high enough) to pass enough current to damage the model but not trip the breaker.  I suspect that even 3-5 Amps will do quite a bit of damage.

[VonRyan]

The guy I mentioned who ruined the pilot truck and pilot of his gs4 was tripping the circuit breaker on the PM42, and he probably didn't hear that tiny relay clicking, and of course rather than back it up from where it stopped, he thought hand-moving it forward some would magically make everything okie-dokie.
And when the damage was done, rather than take his train off so other a could keep running, he left it there and also decided to work on the engine right there on the module.

[Ken Rice]

In my experience most of these meltdowns happen on DC layouts.  But even with DCC, I suspect that some people have the trip current adjusted high enough (and the wiring/track resistance is high enough) to pass enough current to damage the model but not trip the breaker.  I suspect that even 3-5 Amps will do quite a bit of damage.

Yeah the basic problem with those kinds of "shorts" is that they often don't draw enough current to be seen as a short.  You can make a tiny wire or a poorly contacting strip pretty hot with only a couple amps.

My most amusing non-short short was in O scale, two Atlas O B40-8's which I had just put metal KD couplers on.  Had them both on the layout facing opposite ways, ran one of them over to couple up to the other.  A brilliant blue-white glow emitted from the coupler boxes which I believe was the coupler spring and KD greasem (graphite powder) burning.  My 10 amp booster had no problem cranking out the current, which I doubt got anywhere near 10 amps.  I managed to lift one loco off before anything worse happened.  I'd forgotten that even though everything is more or less covered in plastic the metal frame is electrically connected to one of the rails.  And the metal coupler box, screwed on with a metal screw...  After that I was careful to put the metal couplers in plastic coupler boxes on locos!

[mmagliaro]

Ah yes, of course.  It's not a short.  It's just a current path through an unforunate little piece of the truck
that can't handle it.

That very thing happened to me with a wheelset that relied on that conductive paste (i.e. nickel print).
It can easily handle the engine current, but not 3, 4, 5 amps from a booster.  And unless the short
really is a short that overloads the booster, nothing is going to trip

[carlso]

That same thing happened on my GS-4 rear tender truck. It straddled a frog and was stalled for a very short time but it was long enough to melt the axles and if not noticed soon enough it most likely would have melted or partially melted the tender shell. That happened about 5 years ago.

Carl

[victor miranda]

I know heaters are possible when current takes an alternate path.

I looked at the gs-4 trucks and wondered if they might ... bridge a gap?...
or turnout points because of their length and the unusual feature
of having the middle wheel doing pick-up.

It happens, and It does not appear to be a problem unique to the loco.

victor

[SkipGear]

Melted trucks are not unique to the GS-4, I have two EM-1's and a 4-6-0 that prove that point. We have been fighting high resistance issues with our N-Trak club for the past year. The quarter trick will trip the breaker but a stalled/bridged loco will not.

I have one original GS-4 and just finished putting a decoder in another original for a friend. Both get run regularly at shows. No cracked axles. My friends broke a traction tire (it didn't throw it, the tire broke on the track).  I replaced the traction tires on that one with those from a ConCor Hudson. My GS-4 has a little paint under the tires, something I do pretty much out of the box for any loco with traction tires, so I have not had a problem. Both loco's are used to pull the Daylight with all the add on cars whenever they are on the track.