My "New" track cleaning train. Consists of a couple of old Lionel gondolas. One I believe was a postwar gondola (metal frame), the other is a modern one. Both were weathered into DT&I MOW paint before I got them. I turned one into a track cleaning car based on some plans posted here awhile back and sent to me by another member. Mine still needs the scotchbrite pad to do the actual cleaning, but the spring system seems to work OK. I may add a tank car in the future.
Hopefully the Docksider a fellow club member is lettering to DT&I for me will be strong enough to pull it. I used a couple of K-Line GG1 power trucks (diecast ones) for ballast in the cleaning car to hold the springs down. So far they seem to do the job.