New signals, old problems.
The modern signal system that went live on the entire No. 7 line on Monday couldn’t last until the evening rush hour.
Signal malfunctions and a “network communication problem” at Queensboro Plaza in Long Island City delayed No. 7 trains starting around 4 p.m., according to alerts on the NYC Transit subway Twitter account.
The delayed commutes were announced about a half hour after NYC Transit highlighted the benefits of the new signal system, called communications-based train control, on Twitter.
“After we finish optimizing and automating the system and performing other signal work over the coming weeks, we’ll be able to run more trains, more reliably,” the @NYCTSubway account said.
Regular service was restored by 4:46 p.m. — but riders experienced residual delays for some time afterward.
The new communications-based train control signal system replaces decades-old signal equipment. The new system — like one already in use on the L line — will let NYC Transit run up to two more trains an hour.
The new technology replaces a signal system that had more mechanical equipment — and thus more opportunities for breakdowns.
An independent engineer overseeing the No. 7 line work told the MTA board this month that he was worried about problems with the new system that required changes to its design and software.
MTA spokesman Shams Tarek said that it’s unclear if Monday’s delay was related to the new signals.
“Over the next few weeks we’ll be working with the vendor to optimize the system and doing other signal work on the line to complete the transition,” Tarek said.
Though the MTA isn’t sure what caused Monday’s problems, it is sure that “customers will soon enjoy the enhanced reliability and, eventually, increased train frequencies that CBTC [communications-based train control] allows, as currently seen on the L line,” Tarek said.