Thursday’s biting cold weather led to a miserable morning of delays for Metro riders on five of six subway lines as the transit agency struggled with broken rails and broken trains.

In what already had been a bad week for Metro customers, the new problems prolonged the commuting headache. On Wednesday, there were delays on the Blue, Orange and Silver lines. And amid Tuesday’s snowfall, some Metrobus service was curtailed and other routes were shut down.

“We know for anyone standing out on a cold platform this morning, it was a very, very difficult morning,” Metro spokesman Dan Stessel said Thursday, responding to an outpouring of rider complaints about delays. “Every minute seems like 15 minutes in this kind of cold. And we absolutely apologize.”

Some riders said their commutes were twice as long as normal, with many customers standing in frigid outdoor stations waiting for delayed trains.

“I’ve lived in cities that have public transportation, and I have never experienced the level or frequency of glitches that seem to afflict Metro,” said Olivier Knox of Bethesda.

What happens when track rails crack
The recent temperature plunge almost certainly caused Metro rails to crack, contributing to massive delays on several lines Thursday morning. Crews were able to splice together a cracked rail near Prince George's Plaza but had to replace a 39-foot rail section after a severe break near East Falls Church.

(Bonnie Berkowitz And Alberto Cuadra / The Washington Post/Sources: Dan Stessel of WMATA, Capital Weather Gang)

He said that he waited more than half an hour outdoors for a Red Line train at the Grosvenor station and that his normally 30-minute commute to Farragut North took three times longer.

“It was a nuisance and frustrating,” said Knox, who said he has lived in New York and Paris and commuted on the subway systems there.

America Pintabutr of Rockville said she also waited at Grosvenor as several trains packed with riders passed her by. Finally, after an hour in the cold, she decided to give up and go home to wait out the delays. “I paid $2.25 to stand in the cold for an hour and not go anywhere,” she said. “Metro makes money for failing.”

Thursday’s temperatures ranged from a low of 12 degrees to a high of 24 at Reagan National Airport, according to The Washington Post’s Capital Weather Gang, and a low of 4 degrees and a high of 19 at Dulles International Airport.

A big part of Thursday’s mess was caused by a cracked rail near the Prince George’s Plaza station, which caused problems for riders on the Green and Yellow lines, and a damaged rail near the East Falls Church station, which resulted in delays on the Orange and Silver lines, Metro said. The Blue Line had no problems.

Meanwhile, for Knox, Pinta­butr and other Red Line riders, the delays had to do with broken-down trains. “There were trains that had to be off-loaded and taken out of service due to a variety of mechanical issues that can be linked to the weather,” Stessel said.

“The most acute problem was a disabled train outside of Grosvenor,” he said. “That was a brake problem, weather-related. We had to send a second train to tow that train into the Grosvenor station so it could be off-loaded.”

The break in the steel rail near the East Falls Church station, detected about 7:30 a.m., was too severe to be repaired, Stessel said. He said crews had to replace a 39-foot stretch of rail.

The work took until early afternoon, he said. Until then, trains traveling in that area had to share the same track, which caused a slowdown in service.

Roger Kaplan’s commute from Vienna to Federal Triangle, normally 34 minutes, took an hour and 11 minutes, he said. “It was unbelievable.”

He added that he had waited 30 minutes at the Vienna station to board a train. The first one, which was packed, sat for almost 20 minutes — with its doors open — before moving. When Kaplan got on the next train, it didn’t pull out of Vienna for nearly 20 minutes because trains were backed up, a result of the single-tracking.

“It was frustrating,” he said. “My feet were ice blocks by the time I got on a train.”

The damaged rail near Prince George’s Plaza was less severe than the one near East Falls Church, Stessel said. He said trains were forced to single-track for about two hours near Prince George’s Plaza, starting around 8:30 a.m., while workers fixed the crack.

“Steel rails expand in heat and contract in cold,” which can cause them to break, Stessel said, noting that temperatures in the D.C. area took a nose dive this week — from the 60-degree range Sunday to well below freezing Thursday.

Although Stessel apologized repeatedly for Thursday’s frigid inconveniences, he also said the problem of cracked rails isn’t unique to Washington.

“It’s not just Metro,” he said. “Any railroad that operates where there are seasons has the potential to see these kinds of issues occur.”

As for riders comparing Metro unfavorably with other cities’ subways? “Transit systems always seem to run more reliably in cities you don’t live in anymore,” Stessel said.

Aaron Donovan, a spokesman for New York’s Metropolitan Transportation Authority, which operates the nation’s biggest subway system, said his agency deals with cracked rails every winter — including Thursday in Lower Manhattan during the evening rush.

How the problem in New York compares with Metro’s in terms of severity wasn’t immediately clear.

Stessel said, “Our friends up in Boston at the [Massachusetts Bay Transportation Authority] advise their customers: Expect broken rails due to extreme cold temperatures.”

As for the rail-car breakdowns that were blamed on the cold, Stessel said most occurred in Metro’s oldest cars, the 1000 series, manufactured in the mid-1970s. Those cars are to be retired in the next few years and replaced by a new generation, the 7000 series.

“Weather takes a toll on all mechanical equipment,” he said. He added that an “unusually high number of trains” were taken out of service on the Red Line because they had problems with their brakes or doors that were attributable to the weather.

It was little consolation to riders.

Plenty of riders took to social media to express their frustration. One tweeted with the hashtag #MetroClosesDoors — mocking the transit agency’s signature slogan, “Metro Opens Doors.” Others tweeted pictures of packed trains and platforms. Many riders said there was not enough information from Metro about the extent of the delays.

Metro made buses available along the Red Line as riders gave up and bailed from the system.

The morning had started relatively quietly. But shortly after 8 a.m., a Red Line train had brake trouble outside the Grosvenor station. The train was full of passengers, who were stuck on it for 45 minutes.

Stessel said Metro Transit Police went on the train to check on their condition. They were reported to be “very inconvenienced, very frustrated and very delayed,” Stessel said, but there were no reports of medical issues.

“I stood with tons of other people on the platform at Grosvenor for over 45 minutes BEFORE the train left the station and had the problem with its brakes,” rider Allison Lerner said in an e-mail to The Washington Post.

The Red Line situation, in her view? “Dysfunction.”