You are talking about the 6-84373 Announcement Track (http://www.lionel.com/products...ement-track-6-84373/)?
The manual (https://www.lionelsupport.com/...nnouncementTrack.pdf) states that it is for any Trolley or other bump-n-go motorized units.
Being that the entire section is only 15" long, I suspect the isolated component is much too short for any locomotive. I also wonder if the electronics can support the current draw of a more demanding locomotive. Surprisingly, the manual is rather sparse on the operating mechanics and doesn't touch on the sections inability or ability to support running a standard sized locomotive through it and if it could control one. Perhaps tagging @Dave Olson may induce him chime in and let us know...