The MBTA apologized Tuesday after commuters on the Red Line experienced delays because of signal problems and track issues near the Kendall/MIT Station.
Starting around 7 a.m., a signal problem at the station forced the MBTA to manually direct trains through as a safety precaution, officials said.
After diagnosing the signal issue, a crack in the rail was discovered in the vicinity of the signal equipment, MBTA spokeswoman Lisa Battiston said in an e-mail.
While that crack was being repaired, a second crack was found in the area and also repaired, she said.
She said a possible cause might have been the “extremely cold weather as rail becomes brittle during very low temperatures,” noting that winter resiliency work replaced the third rail, not the rails that the trains roll on.
The repairs took longer because crews had to fit their work in the time available between trains passing through the area, she said.
At 3:01 p.m., the MBTA tweeted that regularly scheduled service had resumed.
“The MBTA apologizes to its passengers for the delays this morning as Track and Signal crews worked as quickly and safely as they could to make repairs. The MBTA will provide regularly schedule service during the evening commute,” Battiston said.Martin Finucane of the Globe staff contributed to this report. John R. Ellement can be reached at firstname.lastname@example.org. Follow him on Twitter @JREbosglobe.