"LIRR's Longest Electric Consist?"
In a rare event on April 12th, 2021, Long Island Rail Road train 4210 is seen passing Floral Park station westbound on the Main Line with a whopping 18-car consist. A 6-car M9 test train suffered enroute issues and it was decided to tow the train back to Hillside Yard using deadhead train #4210, which was made up of 12 M7s. LIRR electric trains are usually capped at 12 cars for several reasons, one of which is to prevent overloading power substations.
The nation's busiest passenger railroad depends every day on a fleet of nearly 1,000 multiple unit cars to bring hundreds of thousands of commuters to and from their jobs.