Henryton Tunnel

Henryton Tunnel
East entrance to the tunnel. B&O widened the tunnel for double track in 1865, but converted the entire Old Main Line to single track in 1959, to utilize higher center tunnel clearances.[1]: 174 
Overview
LineOld Main Line Subdivision
LocationHenryton, Maryland
Coordinates39°21′04″N 76°54′46″W / 39.3512°N 76.9128°W / 39.3512; -76.9128
SystemCSX Transportation
StartNear Marriottsville, MD
EndHenryton
Operation
Constructed1849-50
Opened1850
Rebuilt1865, 1903
OwnerCSX
TrafficTrain
CharacterFreight
Technical
Length430.4 ft (131.2 m)
No. of tracks1
Track gauge1,435 mm (4 ft 8+12 in)
Width30 ft (9.1 m)

The Henryton Tunnel, located near Henryton in southern Carroll County, Maryland, is the third-oldest tunnel in the world that remains in active railroad use.[2] Constructed by the Baltimore and Ohio (B&O) Railroad and opened around 1850, it was the first tunnel constructed on the B&O's Old Main Line. In 1865 the tunnel was widened to accommodate double track. It was rebuilt into its current form in 1903. The tunnel has brick portals and lining. The coping and footings are concrete.[1]: 452 

  1. ^ a b Harwood, Jr., Herbert H. (1979). Impossible Challenge: The Baltimore & Ohio Railroad in Maryland. Baltimore, MD: Barnard, Roberts. ISBN 0-934118-17-5.
  2. ^ Steve Okonski's B&O RR Photo Tours from Woodstock to Henryton