Metro

How LIRR blew it in shutdown

The LIRR’s misguided efforts to improve its new $56 million signals system — straying from the contractor’s plans — led to a catastrophic service shutdown one stormy day last September, according to a report released yesterday.

The Long Island Rail Road added a tiny piece of computer equipment — known as a “serial server” — to access the new system remotely, according to a report by MTA Inspector General Barry Kluger.

That decision unintentionally paved the way for the Sept. 29 shutdown, which stranded tens of thousands of riders after lightning struck tracks near the Jamaica station in Queens.

All signals west of the station blew out.

Kluger’s report blamed the outage squarely on the modification.

“This wrong connector created the pathway by which the power surge generated by the lightning damaged the signal system and brought it down,” the report said.

Amazingly, the LIRR had never bothered to check with the system’s designer — the Italian technology company Ansaldo STS — to see if tinkering with the original plans would cause problems.

The situation became worse when an LIRR employee made a programming error that killed the signals that were still working.

Meanwhile, the backup system that was supposed to kick in during emergencies also got fried — again because of a bad installation by the LIRR.

In that case, the railroad workers — whose union contracts stipulated that they do the installation instead of the system’s designers — mistakenly linked the backup and main systems.

Because of that, problems on the main system also affected the backup, according to the report.

The report also faulted the LIRR for not communicating effectively with stranded customers.

In one instance, conductors inexplicably told riders trapped aboard trains that they were stuck while waiting on “paperwork.”

In addition, passengers at overflowing Penn Station who had signed up for mobile alerts were getting messages advising them to take the subway to Jamaica for LIRR service east.

But no workers at Penn Station could confirm that service was, indeed, available at Jamaica.

It took the LIRR a full 12 hours to restore service.

The MTA, in a statement, said it has made several corrections since last year’s shutdown to prevent a repeat.