Check the underside of your KATO double stack

[trainforfun]

I had too remove some cars from the layout to ballast some sections , to my surprise I found number of trip pins , and spikes sticked to the underside of these well cars , in fact the magnet use by KATO under their containers are very strong and they kind of made a cleanup of my tracks !!!
It could become problematic if too many are picked up under the same container , particularly when passing over a turnout , you could search for a very long time that short circuit ....   

[jagged ben]

JTC containers will probably do this even more so.

[Jbub]

I saw a similar occurrence at the Cheyenne train show a couple of weeks ago. One of our members pulled his well car off the track and noticed a lot of metal shavings under the magnet. Probably a good thing considering that could have gotten into an engine.

[Rivet Miscounter]

Huh, hadn't thought of that.   I'm in Z but still a possible issue with the AZL/MTL cars when using a magnet system for the containers.

[thomasjmdavis]

My time frame doesn't allow for containers, other than a few oddball experimental things, but I am thinking I should equip a few of my old metal flatcars with magnet loads to run around the track now and again.  The point about it being better to have the metal bits stuck to the bottom of the car, rather than in the gears or electrics of the locomotive, is well taken.  Put a couple such cars into a work train.

[jereising]

Many of the good 'ol Aztec track cleaning cars have magnets, and I most always find some schmutz after I run the cleaning train...

[carlso]

I sure miss John's products.

Carl