Old Main Line Subdivision

Old Main Line Subdivision
Eastbound coal train on the Old Main Line Subdivision at Monrovia in 2011
Overview
Status	operational
Locale	Maryland, USA
Service
System	CSX Transportation
Technical
Track gauge	4 ft 8+1⁄2 in (1,435 mm) standard gauge
Old Main Line in 1917 Legend in 1917 mi Baltimore Terminal Sub. 0.0 Relay Washington Branch 2.5 Orange Grove 3.2 Ilchester Tunnel 3.5 Ilchester Bridge 3.6 Ilchester 4.4 Lees 4.7 Gray 5.7 Ellicott City 6.2 Sucker Branch Bridge 7.9 Union Dam Tunnel 9.2 HS Tower 9.5 Hollofield 10.6 Daniels Bridge 10.9 Alberton 11.6 Brice Run Bridge 12.1 Dorsey’s Run Tunnel 12.7 Eureka Bridge 12.8 Line Run Bridge 12.9 Davis Tunnel 13.3 Davis 13.8 Davis Branch Bridge 14.6 Woodstock 17.1 Marriottsville 17.7 Henryton Bridge 17.8 Henryton Tunnel 17.9 Henryton 19.7 Gorsuch 21.6 Sykesville Station 22.4 Sykesville Tunnel 22.9 Gaither 24.2 Hood’s Mill 26.1 Morgan 26.5 Woodbine Tunnel 26.8 Woodbine 26.9 Gillis Falls Bridge 29.5 Watersville 30.6 Watersville Junction 31.8 Mount Airy 32.6 Mount Airy Tunnel 33.9 Mount Airy Junction 37.4 Bush Creek Bridge 39.5 Monrovia 40.0 Monrovia Tower 42.9 Ijamsville 44.1 Hartman Tunnel 46.1 Reel’s Mill 47.4 Monocacy River Bridge 47.5 Frederick Junction Frederick Branch 43.5 Frederick (South Market Street) 48.9 Ballenger Creek Bridge 50.0 Lime Kiln 51.7 Buckeystown 53.7 Adamstown 53.9 Adamstown Junction Adamstown Cutoff 58.0 Point of Rocks Washington Junction Metropolitan Branch 58.5 Point of Rocks Tunnel 60.1 Catoctin Tunnel to Brunswick

The Old Main Line Subdivision is a railroad line owned and operated by CSX Transportation in the U.S. state of Maryland. The line runs from Relay (outside Baltimore) west to Point of Rocks, and was once the main line of the Baltimore and Ohio Railroad, one of the oldest rail lines in the United States. At its east end, it has junctions with the Capital Subdivision and the Baltimore Terminal Subdivision; its west end has a junction with the Metropolitan Subdivision.^[1][2]