(Adds details on operations from Union Pacific)
Aug 31 (Reuters) - Union Pacific Corp said on Thursday that workers completed repairs on some rail infrastructure to the north and south of storm-battered Houston, but many routes in southern Texas were still being inspected, in some cases by helicopters and drones.
It also said switching operations will begin over the next two days in its primary rail freight yards in the Houston area, Englewood and Settegast.
Major U.S. railroads have warned that it could be a long time before normal operations resume in the Houston area, where Tropical Storm Harvey has caused catastrophic flooding. Harvey came ashore over the weekend as the most powerful hurricane to hit the state in a half-century.
Union Pacific and Berkshire Hathaway Inc’s BNSF Railway, the two leading U.S. railroads, and regional railroad Kansas City Southern have suspended operations in the area affected by the storm.
Union Pacific said some freight was starting to move at locations in the Houston area, but as of Wednesday, it had held back shipments destined for Brownsville and 36 rail stations in the Beaumont and Orange areas, including Port Arthur, all in Texas.
The railroad said workers on Thursday were focusing on repairs between Houston and San Antonio and inspecting track, signals and bridges where road access was blocked, such as the area of Baytown, Texas. (Reporting by Eric M. Johnson in Seattle; Editing by Dan Grebler)