Tensions flared between Metro board members and the agency’s leadership Thursday as staff made their case for axing late-night service to create larger work windows for maintenance crews.

As senior management laid out specifics of the proposal, including how the extra hours would be used, board members pushed back, asking whether alternatives were considered, why Metro needed more work time than peer systems, and whether there was data to back up claims that more time is needed.

“You just startled me by saying that we used to do X, Y, however we don’t do it anymore,” Board member Tom Bulger said to Chief Operating Officer Joseph Leader.

Referring to maintenance practices aimed at keeping the system in a state of good repair, Bulger continued: “How does that happen? That we used to do stuff that was necessary and now we don’t and the board . . . just finds out about it this morning?”

Bulger, who represents the District, demanded an inventory of the work being performed, including projects that are completed and those that are “dropped.”

Leader said he was making the broader point that Metro needs more time to work on its tracks.

“Chambers Brothers time?” Bulger said. “What are you talking about time?”

“Time-wise, the maintenance windows … more time to do work,” Leader replied.

The exchange illustrated the board’s apparent skepticism of staff claims that restoring the system could only be achieved by expanding nighttime maintenance windows.

Andrew Off, assistant general manager for transit infrastructure and engineering services, likened Metro’s current undertaking — rehabilitating aging infrastructure after 40 years of deferred maintenance — to open-heart surgery. The dilapidated state of the tracks requires extremely careful maneuvering, evidenced by the dozens of speed restrictions that transit agency has imposed since the July 29 derailment of a Silver Line train.

“At some point we need to get away from just fixing stuff that’s already broken,” Off said.

Off said Metro needs nighttime repair windows to avoid a potential “SafeTrack 2.0.”  In the past, he said, Metro didn’t perform nonemergency track work on Friday and Saturday nights because the maintenance windows provided by midnight to 3 a.m. service were too small.

But board member Robert Lauby, who is chief safety officer for the Federal Railroad Administration, asked if restoring the tracks could be achieved through more modest schedule adjustments than scrapping late-night service.

“It seems to me that since we have a two-track system here, that expanded work zones could be established in the evenings on one track, while maintaining a level of service on the other,” he said. “Tell me, why wouldn’t a solution that basically shut down one track, maybe 8 in the evening … get these things done?”

Staff responded that certain activities, like a nighttime program to identify degraded power cables, require power to be cut to both tracks. In other cases, Metro officials said, having trains passing at periodic intervals on one track, while work crews were aggressively restoring another, would be too disruptive to dozens of workers performing the work.

But Lauby pushed back, asking: would a train passing every 20-minutes really pose that much of a disruption?

Later in the meeting, the exchange between Leader and Bulger shed light on Leader’s philosophy, who was brought in by Wiedefeld from the New York subway to help turn around Metro.

“Moving forward, it doesn’t matter to me what happened in the past,” Leader said. “It’s what’s happening now and where do we wanna go. That’s what I can change. And that’s what I’m tasked to do.”

Bulger pressed for evidence of change, rather than talk.

“If you can’t tell us the past then fine, water under the bridge,” Bulger said. “ … It’s just a shock.”

Metro wants to cut back on late-night service to make more time for repairs. Here are the four proposals on the table and how they could affect your commute. (Claritza Jimenez, Julio Negron/The Washington Post)