Complex sentence: The New Haven locomotives were dual-powered, and came equipped with third-rail pickups to allow them to operate in New York's Grand Central Terminal, and were the first dual-power locomotives light enough to operate on the Park Avenue viaduct.
Split into simpler sentences: The New Haven locomotives were dual-powered, and came equipped with third-rail pickups to allow them to operate in New York's Grand Central Terminal. These were the first dual-power locomotives light enough to operate on the Park Avenue viaduct.