Isolator Track

It's just that they ran that through the assembly line that puts the shunts in, that's the only difference in the plastic for the isolation track.

Your picture looks similar to one of my "5 INCH ISOLATOR" track sections.  If you turn your track over and you see an insulated gap in the middle of one of the outside rails, then it is a "5 INCH ISOLATOR" track section.  My isolator section does not have the shunt connection between the two outside rails, but your section should work as long as you are very careful how you orient the track, or you could just remove the shunt. These sections come in pairs in the Lionel 6-12029 Accessory Activator pack and they are used to activate accessories such as the No. 145 Automatic Gateman. The 6-12029 set is 20" long and it can be made longer.  With tubular track you can get the same effect with a section or more of track with one insolated outside rail with an insulating pin on each end and a lockon in the middle. FasTrack does not have insulating pins so they have three different types of track to handle those times when you would want an insulated rail. No. 6-12060 is a 5 inch section with an insulated gap in all three rails, and all of the 1-3/8 inch sections have an insulated gap in the center rail.

Note that you have different screw holes than mine... Could yours be an early version?

gunrunnerjohn,

so the 5” “isolator” track with the shunt installed is simply a 5” piece of track.”  If the shunt is removed can it be used between insulated tracks to extend the distance that ac accessory (in this case crossing lights) operates?  If not, what is the function of an Isolator track.

John in California, all of my experiece os with tubular track where I have used insulated rails to operate accessories. I’m trying to follow that principle with the fastrack around my Christmas tree.   I’ve used the track with the cut  rails. I’ve removed the wires connecting one outside rail across the cut to begin the insulated section. I’ve used two 10” rails with the shunts removed to provide the distance I needed and then placed another 5” piece with the cut track at the other end.  Because I have no need for aux power on this simple layout, I connected the crossing signal to the insulated outer rail and the center power rail and it works!

I think they just ended up using the base on the normal track line.  OTOH, the picture of the isolated track doesn't look any different than a 5" section of track from the top.  At some point there has to be a break in the rail in order to use it like the classic isolated track.