You know the wire system above the Skokie Swift trains? That's called a "catenary system," and the Skokie Swift is the last CTA line to use it. Well, the catenary system has fallen into disrepair, and instead of fixing it, the CTA is replacing it with the more conventional third-rail system. In honor of this passing, the Central Electric Railfans' Association is hosting three last trips on the line, on CTA Historic Trains, Sunday, September 5. Three two-hour trips will depart from the Yellow Line Dempster stop at 9 am, 12 pm and 3 pm. Tickets are $20. Info on reserving seats can be found on CERA's site.