Most anyone who’s ridden Metro has seen a broken escalator — or two — on the system’s five rail lines. Even Metro General Manager Richard Sarles has been known to make a crack about having to walk up escalator stairs when they are not working.

But at board committee meetings Thursday, it became apparent that a specific hiccup is causing delays to some escalator work.

Metro’s board chairman, Tom Downs, questioned the transit agency’s top officials as to why the wrong parts were ordered for nine broken escalators, repairs to which, he said, will now be delayed.

His question came after Metro staff members gave a report to the board’s customer service committee saying that several of its on-time performance measures — essentially Metro’s own report card on its trains and buses — had improved.

Downs said he recalled learning of the incorrect parts and delays in the escalator work in an update on the budget that was given to board members.

“It showed that nine escalators were not going to be rebuilt in fiscal year 2014 because a contractor had ordered the wrong parts,” he said.

Downs asked who the contractor was.

No one seemed to have — or wanted to give — an immediate answer.

Sarles and his Number 2, Rob Troup, who runs rail operations, took notes. Metro spokesman Dan Stessel did not immediately respond to an e-mail Thursday asking for the name of the contractor.

Earlier this year, Metro awarded Kone, a major escalator and elevator contractor, a $151.1 million deal to replace and modernize 128 escalators in its system over the next few years.

It was unclear Thursday afternoon whether the wrong parts were ordered as part of that contract or not.

Mort Downey, a vice chairman of the board, said after the meeting that the report Downs was referring to showed that 54 escalators were to be done this year.

“We promised the public 54 would get fixed and now nine of them won’t,” he said. “They’re no longer in this year’s plan.”