Score a big victory for the politically potent San Francisco Bicycle Coalition, which won approval the other day for protected bike lanes along several blocks of upper Market Street — despite a Fire Department protest that the reconfiguration will interfere with ladder trucks in an emergency.

“The design materially compromises the safety of firefighters and local residents,” Fire Chief Joanne Hayes-White warned in a letter to the Municipal Transportation Agency commission.

At issue is a nearly mile-long strip of Market between Octavia and Castro streets. Under the plan, the city will install protected bike lanes in both directions.

The redo includes a bike lane on two blocks near Octavia that will be located next to the curb and be buffered from traffic by a lane for parked cars.

And therein lies the rub — because, as Hayes-White tells us, the parking lane will be right in the spot where a ladder truck would normally pull up to an emergency scene.

With the parking lane in the way, ladder trucks will have to stop under or next to Muni’s overhead wires, Hayes-White said. That will make it harder to lift the ladder to rescue people trapped in burning buildings, she warned, and will also create an electrical shock hazard for firefighters.

The chief also noted that Market is a major east-west artery, and the redo means it will be shut down virtually every time a group of fire trucks pulls up to an emergency.

Muni, however, thinks the fire chief’s concern is overblown — particularly when it comes to her fears about truck ladders hitting the overhead wires. We’re told Muni tested some ladder trucks and concluded they had plenty of room to maneuver around the wires.

Transit agency spokesman Paul Rose declined to discuss the tests, but said that overall, “we believe the proposal is responsive to the Fire Department’s concerns and ... doesn’t substantially alter existing fire access.”

The bike coalition lobbied hard for the the $9.7 million redo, which also includes curb bulb-outs and improved pedestrian crossings. The group showered MTA chief Ed Reiskin and the commission with 300 emails supporting the project and turned out a standing-room-only crowd for Tuesday’s vote.

“It was impressive by my book,” said bike coalition spokesman Chris Cassidy.

The MTA commission agreed and voted unanimously to approve the new lanes, despite the Fire Department’s concerns.

“This is a whole new wrinkle with them not listening to us,” said Tom O’Connor, head of the firefighters union.

Mayor Ed Lee himself signaled his support for the biking crowd last year when he issued a directive pledging support for protective bike lanes in the city, and calling for at least 13 miles of additional bike lanes and related infrastructure annually.

Safe for bikes, perhaps, but maybe less so for anyone needing help in an emergency.

San Francisco Chronicle columnists Phillip Matier and Andrew Ross appear Sundays, Mondays and Wednesdays. Matier can be seen on the KPIX TV morning and evening news. He can also be heard on KCBS radio Monday through Friday at 7:50 a.m. and 5:50 p.m. Got a tip? Call (415) 777-8815, or email matierandross@sfchronicle.com. Twitter: @matierandross