The Union Tunnel is a railroad tunnel on

Amtrak The National Railroad Passenger Corporation, Trade name, doing business as Amtrak (; ), is the national Passenger train, passenger railroad company of the United States. It operates intercity rail service in 46 of the 48 contiguous United Stat ...

Northeast Corridor The Northeast Corridor (NEC) is an electrified railroad line in the Northeast megalopolis of the United States. Owned primarily by Amtrak, it runs from Boston in the north to Washington, D.C., in the south, with major stops in Providence, Rhod ...

Baltimore, Maryland Baltimore is the List of municipalities in Maryland, most populous city in the U.S. state of Maryland. With a population of 585,708 at the 2020 United States census, 2020 census and estimated at 568,271 in 2024, it is the List of United States ...

adjacent to

Pennsylvania Station Pennsylvania Station or Penn Station may refer to: Current train stations * Baltimore Penn Station * New York Penn Station ** Pennsylvania Station (1910–1963), the predecessor to the present New York City station * Newark Penn Station Trai ...

that was built to connect the

Pennsylvania Railroad The Pennsylvania Railroad ( reporting mark PRR), legal name as the Pennsylvania Railroad Company, also known as the "Pennsy," was an American Class I railroad that was established in 1846 and headquartered in Philadelphia, Pennsylvania. At its ...

's original mainline to

Philadelphia, Pennsylvania Philadelphia ( ), colloquially referred to as Philly, is the List of municipalities in Pennsylvania, most populous city in the U.S. state of Pennsylvania and the List of United States cities by population, sixth-most populous city in the Unit ...

and points north. The tunnel consists of two parallel bores: the original bore from 1873 has a single track, while a newer bore from 1934 has two tracks.

Original tunnel

The Union Tunnel was originally constructed as part of the Union Railroad and served as the northern and eastern approach to

Calvert Street Station Calvert Street Station served railroad passengers of the Northern Central Railway in Baltimore, Maryland, from 1850 until 1948. It served as the terminus for the second railway chartered in Maryland, which eventually was expanded into a network ...

. In all, the Union Railroad was in length, extending from the northern terminus of the

Baltimore and Potomac Railroad The Baltimore and Potomac Railroad (B&P) operated from Baltimore, Maryland, southwest to Washington, D.C., from 1872 to 1902. Owned and operated by the Pennsylvania Railroad, it was the second railroad company to connect the nation's capital to ...

(B&P) and the southern terminus of the

Northern Central Railway The Northern Central Railway (NCRY) was a Class I Railroad in the United States connecting Baltimore, Maryland, with Sunbury, Pennsylvania, along the Susquehanna River. Completed in 1858, the line came under the control of the Pennsylvania R ...

(NCRY) to the southern terminus of the Philadelphia, Wilmington & Baltimore Railroad. It connected with the B&P and the NCRY at the Calvert Street Station, since replaced by the current

, near the northern portal of the

Baltimore and Potomac Tunnel The Baltimore and Potomac Tunnel (or B&P Tunnel) is a double-tracked, masonry arch railroad tunnel on the Northeast Corridor in Baltimore, Maryland, just west of Pennsylvania Station (Baltimore). Opened in 1873, the tunnel is the oldest tunnel ...

. The Union Railroad joined the Northern Central at Bayview Junction, Maryland on the northeast side of Baltimore. It also included a spur from just west of Bayview Junction that went due South to Canton. In 1866 the Canton Company of Baltimore obtained a charter from State of Maryland to build the Union Railroad. Active steps to finance construction of the railroad and tunnel came only in the autumn of 1870, and actual construction began on May 1, 1871. On July 24, 1873, the first train passed through the tunnel. The original tunnel began at Bond Street, and passed under the bed of Hoffman Street to Greenmount Avenue, crossing under Dallas, Caroline, Spring and Eden Streets, Central and Harford Avenues, and Ensor, Valley and McKim Streets. Its length is . The total cost of the road and tunnel was some $3,000,000. As soon as the Union Railroad was completed, the Northern Central Railway obtained the right to use it, and in February, 1882, the Northern Central purchased the Union Railroad stock from the Canton Company, and assumed control March 1 of the same year.

Modifications

Additional work was done on the tunnels between 1928 and 1935 to prepare for the

electrification Electrification is the process of powering by electricity and, in many contexts, the introduction of such power by changing over from an earlier power source. In the context of history of technology and economic development, electrification refe ...

of the Pennsylvania Railroad's

New York New York most commonly refers to: * New York (state), a state in the northeastern United States * New York City, the most populous city in the United States, located in the state of New York New York may also refer to: Places United Kingdom * ...

Washington Washington most commonly refers to: * George Washington (1732–1799), the first president of the United States * Washington (state), a state in the Pacific Northwest of the United States * Washington, D.C., the capital of the United States ** A ...

mainline. The original Union Tunnel, too small to accommodate

overhead catenary An overhead line or overhead wire is an electrical cable that is used to transmit electrical energy to electric locomotives, Electric multiple unit, electric multiple units, trolleybuses or trams. The generic term used by the International Union ...

on its two tracks, was supplemented by an adjacent double-track tunnel to the east, then converted to a single track which provided adequate clearance for electrification.

References

Amtrak tunnels Pennsylvania Railroad tunnels Railroad tunnels in Maryland Tunnels in Baltimore Tunnels completed in 1873 1873 establishments in Maryland {{US-tunnel-stub

Original tunnel

Modifications

See also

References