GUILDERLAND — An inspection of a CSX Mainline Track between Schenectady and Selkirk last week revealed a faulty switch on a line running through the Northeastern Industrial Park.

The inspection was the eighth one in the state, ordered by Governor Andrew Cuomo, to ensure that crude oil transporters are up to the proper safety standards.

The targeted inspection campaign began in February as a response to out-of-state disasters involving the transport of crude oil from the Bakken oil fields in North Dakota.

The latest round of tank car and rail inspections uncovered 100 defects across 95 miles of tracks and 704 cars.

The faulty switch in Guilderland, according to Beau Duffy, a spokesperson for the state’s Department of Transportation, which conducted the inspection in conjunction with the Federal Railroad Administration, was too narrow by an eighth of an inch.

A railroad switch guides trains from one track to another.

“When the rails are inspected, first and foremost, it’s a visual inspection, but it’s also taking measurements of the hardware,” said Duffy.

In this case, he said, the distance between the “frog point” — the point at which two rails cross — and the outside rail was too narrow, and it could have caused a wheel to derail by dropping into a gap.

After the defect was discovered, the speed limit on the track was temporarily reduced from 50 miles per hour to 25 miles per hour, while the switch was fixed.

CSX owns the track and Duffy said the company was “very responsive” to the situation and the speed limit has since been restored.

Four other non-critical defects were discovered, including loose bolts, along a 15-mile stretch from Schenectady to Selkirk. Non-critical rail defects must be fixed within 30 days.