Rail commuters who endured a very long week due to derailment-related track work made their way into New York’s Penn Station on Friday with assurances that the repairs were finished – just in time for the weekend, but not quite in time for the morning commute.

Amtrak, which owns and maintains tracks used by New Jersey Transit and the Long Island Rail Road, said at 7:30 a.m. Friday that testing and inspections were completed. But, NJ Transit said there was still work being done and warned that delays were possible.

By that time, the Long Island Rail Road had already canceled 10 rush-hour trains into Manhattan and terminated four others at stations in Queens.

The derailment of a NJ Transit commuter train Monday as it approached the station platform ignited a spat between Amtrak and Republican New Jersey Gov. Chris Christie, who angrily demanded a refund of money already paid by the state to Amtrak for maintenance and repairs.

The LIRR also unleashed its ire on Friday, issuing a statement that said: “Because Amtrak crews did not finish track repair work by 4 a.m. as promised and because they did not grant access to tracks overnight so that Long Island Rail Road could pre-position trains, LIRR is forced to once again operate a reduced morning rush-hour schedule.”

The disruptions and delays to rail service up and down the northeastern U.S. apparently were caused by a weakening of the timber ties sitting under a piece of track in Penn Station. Monday’s derailment knocked out eight of 21 tracks maintained by Amtrak.

In another incident, on March 24, an outbound Amtrak train derailed at Penn Station and scraped against an inbound NJ Transit train.

The two derailments highlighted the challenges posed by Amtrak’s aging infrastructure and the myriad ways in which the system can go awry.

(AP)