SCHENECTADY — Amtrak is preparing for a shift of its upstate trains back to Grand Central Terminal this summer.

At the Empire State Passengers Association's 38th annual membership meeting Saturday in Schenectady, Kevin Chittenden, Amtrak's Empire District general superintendent, said the plan is to close the double-track Empire Connector that runs from the Metro-North commuter railroad mainline at Spuyten Duyvil to Penn Station for rehabilitation work for three months this summer.

The work will divert all upstate trains to Grand Central.

"The Spuyten Duyvil Bridge was flooded after Sandy and suffered significant damage on the base of the bridge that needs to be repaired," Chittenden told the audience of about 100. "While the bridge is being repaired we're going to take advantage of other work that needs to be done on the Empire Connector."

That work includes track and tunnel repairs to the Empire Connector, much of which has not seen improvements done since the 1980s and 1990s, Chittenden said. However, he said he could not yet comment on changes to train schedules.

Engineers and conductors are also being trained to travel the Metro North line into Grand Central.

Amtrak also is looking for spare FL-9 locomotives to lease or borrow because they have a door on the front through which an engineer could escape from if necessary. Two of the four tracks into Grand Central are in their own tunnels with not enough clearance to open the side door of the current locomotive fleet.

Another alternative is a cab car, where controls for the engineer would be in a cab at the front of a passenger coach, much like the motorman's cab in a subway train. The locomotive would be at the back of the train.

Rail service officials also highlighted past, current and future projects at Saturday's meeting, including the recently completed improvements at the Albany Rensselaer Station and the Albany-Schenectady double track, and a new station in Schenectady set to be completed in October.

"We're investing more today in our infrastructure in New York State than in any other time in history," said Ronald Epstein, executive deputy commissioner of the New York State Department of Transportation.