Workers at New York’s Pennsylvania Station are slightly ahead of schedule in the eight-week maintenance plan that has upended commutes by reducing train service into Manhattan. Crews at Amtrak’s depot replaced switches and made other repairs at “A Interlocking,” a web of tracks in the area of two derailments in April and March, according to Scot Naparstek, chief operating officer of the national passenger railroad. Though New York Governor Andrew Cuomo had predicted “the summer of hell,” major troubles failed to materialize for New Jersey Transit and Long Island Rail Road riders forced to alter or even suspend their commutes. “We couldn’t have asked for more,” Naparstek said in the first of planned weekly conference call updates with reporters. “We are actually a little bit ahead of schedule.” It’s too soon to say, though, whether the relatively smooth operations will continue, or whether work may conclude before the Sept. 1 target. Crowding was manageable, he said, and no more service cuts are planned. “It’s the right number of trains and the spacing of trains is appropriate,” Naparstek said.