I was in a gift shop in Estes Park CO a few weeks back and I found some rocks for sale. I think they are called Magnatite. Gloss black, probably from polishing, 2 sides cut flat so they will stack. Magnetic as all get out! Sign said, “All you can stuff in bag, for $5”. Bag was small jewelry type but I still managed to get about 25 in there. Had no idea what I would use them for, but the price was right. Then I started to put some magnets back on my track after not using them for years. Re-discovered why I stopped using them. De-rails some of my cars and engines. Thought about the Magnatite. Put a rock UNDER the track, not even above the tie top level. Worked great! No possible obstruction. Thought I would paint it flat grey to go with my balast, but decided against that so I could find the darn things when I needed to. Hope this may help some of you out there.
Now that’s a cool idea.
Dave