According to the September 1983 issue of Trains Magazine, Amtrak FL9 488 was previously numbered Amtrak 239. It was originally New York New Haven & Hartford (NYNH&H, or simply the New Haven) 2016 (c/n 21962), built between July-November 1957, later under Penn-Central ownership (the NH was added to the PC organization on January 1, 1969), it was renumbered 5016. It had 1750 horsepower produced by a 16-567C prime mover, and the idea was to shut the diesel down at Woodlawn Junction and run under third rail 600 volts DC power into Grand Central. Under the PC ownership however, the diesels were kept fired up until the entrance to Park Avenue Tunnel at 96th Street in Manhattan, but only if the crew knew they had a good unit. Sometimes, deteriorating batteries would prevent restarting the diesel once it had been shut down, but more often the problem was the electrically operated air compressor had become defective, and the main generator, run by the diesel, was necessary to keep the brake system charged. So, despite regulations to the contrary, the echoes of rumbling 567's became familiar sounds in the catacombs of Grand Central, with resulting limited visibility in the tunnels during morning and evening rush hours. Penn-Central's assets were conveyed to Conrail on April 1, 1976, and CR sold 12 FL9's to Amtrak. During 1978-80, Amtrak sent six of its FL9's to Morrison-Knudsen in Boise, Idaho for rebuilding, including the capability to provide Head End Power (HEP) to Amtrak's new and rebuilt cars. The FL9's returned with air horns replacing their New Haven Hancock air whistles. The US Congress mandated that Conrail exit the passenger business on January 1, 1983, so the remainder of CR's FL9's were sold off to commuter agencies.

For these locomotives to be of any use to Amtrak in the near future, they will have to be turned, and the quickest way at this location would be to wye them through Union Avenue Interlocking, so we are probably looking at a typical 'hurry up and wait' situation until traffic clears.