Condensation caused Mon Incline to stop midway, and system will remain closed until a solution is found

Pittsburgh Regional Transit announced Monday that condensation created by an air-conditioning unit caused the Monongahela Incline to stop unexpectedly on Friday, but the incline will remain closed while the agency finds a way to mitigate the problem.

The condensation tripped an emergency brake about 5 p.m. Friday with cars on parallel tracks about 50 feet from the top and bottom of Mount Washington. The air-conditioning unit is in the basement of the Grandview Avenue station and attached to the electrical cabinet that contains the circuitry to control the incline’s motor so that the panel doesn’t overheat, but the condensation caused the system to shut off the motor, spokesman Adam Brandolph said.

The control system was installed last year as part of an $8.1 million upgrade to the incline that also included returning its decor to the same style as when it opened in the 1870s. The incline will remain closed while engineers design a method to fix the condensation problem and test the system to make sure it can operate without stopping before cars reach the stations.

There is no estimate how long that might take.

Brandolph said shuttle buses will operate between Mount Washington and Station Square as drivers are available, but he encouraged commuters to use the Duquesne Incline or the 40 Mount Washington bus as alternatives while the Monongahela Incline is closed. About 1,000 riders use the incline on weekdays and about 4,500 on weekends.

In Friday’s incident, one car stopped near the top at Grandview Avenue with three passengers and the other near the bottom at Station Square with nine passengers. The agency told riders on the public address system there was an unknown issue, and Port Authority police and Pittsburgh police, firefighters and EMTs responded.

After about 30 minutes, Brandolph said, personnel used an emergency walkway between the tracks to take water to passengers and make sure they were in good condition. They appeared concerned but not injured, he said.

Emergency personnel were preparing to evacuate the riders when the system returned to operation about 6:05 p.m. None of the passengers were injured, but Brandolph said the nine riders he saw “were just a little shaken” from the experience.

Brandolph said the agency will do extensive test runs to make sure it is safe before the incline reopens. It’s not clear whether the state will have to inspect the incline before it can resume operation.

The incline reopened in early March after an eight-month renovation project. Brandolph said the control panel and air conditioning unit were part of that upgrade.