Fort McHenry Tunnel

Infobox_Bridge
bridge_name= Fort McHenry Tunnel


caption= Northbound in the E-ZPass lane.
official_name= Fort McHenry Tunnel
also_known_as=
carries= 8 lanes of I-95
crosses= Patapsco River
locale= Baltimore, Maryland
maint= MTA
id=
design=
mainspan=
length=
width=
clearance=12 feet 6 inches
below=
traffic=
open= November 23, 1985
closed=
toll= $2.00
map_cue=
map_

map_width=

, under which it passes.

The tunnel, opened on November 23, 1985, closed a gap in the East Coast’s most important interstate route, Interstate 95, between Maine and Florida. It also is the largest underwater highway tunnel built by the immersed tube method and the widest vehicular tunnel ever built by that same method. At the time of its opening it was the most expensive underwater tunnel project in the United States, but that figure has since been surpassed by the Big Dig project in Boston, Massachusetts. The Ft. McHenry Tunnel is one of seven toll facilities operated and maintained by the Maryland Transportation Authority.

The toll rate in 2008 for cars is $2.00, paid in both directions. Vehicles with "more than" two axles pay an additional $2.00 per extra axle.

Background

Originally, plans called for an eight-lane bridge across the Baltimore Harbor to complete the final section of Interstate 95 in Maryland. However, it was next determined that a bridge would have had a negative environmental and aesthetic impact on the nearby National Monument and Historic Site at Fort McHenry, and also on the neighboring residential communities of Locust Point and Fells Point. An eight-lane 1.7-mile (2.7 km) tunnel was proposed as an alternative. This tunnel, as completed, extends from the Locust Point peninsula, passes south of Fort McHenry under the harbor navigational channel, and rises to surface grade in the Canton industrial area of Southeast Baltimore.

The tunnel's route near Fort McHenry, and below the shipping channel prompted, the design of the world’s first tunnel sections that curved both vertically and horizontally. The tunnel sections were manufactured in Port Deposit, Maryland, and they were floated to the site using tugboats.

The tunnel was built using the open-trench method, in which prefabricated tunnel sections were sunk in a trench dredged in the harbor’s bottom. The sections were then joined underwater. A dredge-disposal site for materials removed from the tunnel trench was created at the nearby Helen Delich Bentley Port of Baltimore Seagirt Marine Terminal, resulting in 136 acres (55 hectares) of new, usable land. The Ft. McHenry Tunnel was opened on time and under its budget, and it continues to be a vital transportation link in the Mid-Atlantic region.

Before and during the Civil War, a tunnel had been dug from the B & O Railroad's Camden Station south to the north side of Federal Hill, and then to Fort McHenry. During the consruction of the Ft. McHenry Tennel, some houses in the Federal Hill neighborhood collapsed when that brick-lined tunnel collapsed. That tunnel was probably built by the U.S. Army and fell from use after the Civil War.

Notes

*The Ft. McHenry Tunnel was constructed from June 1980 to November 1985, at a cost of about 750 million dollars.
*The tunnel's annual traffic in 2003 was 44.1 million vehicles. Approximately 115,000 vehicles was the Annual average daily traffic.

Sources: Maryland Transportation Authority

ee also

*Baltimore Harbor Tunnel
*Highways along the BosWash corridor

External links

* [http://www.mdta.state.md.us/mdta/servlet/dispatchServlet?url=/TollFacilities/FortMcHenryTunnel.jsp Maryland Transportation Authority, Fort McHenry Tunnel website]
* [http://www.roadstothefuture.com/Fort_McHenry_Tunnel.html Fort_McHenry_Tunnel] , by Roads to the Future
* [http://www.dcroads.net/crossings/fort-mchenry/ Steve Anderson's DCroads.net: Fort McHenry Tunnel (I-95)]

Crossings navbox
structure=Crossings
place=Patapsco River
bridge=Fort McHenry Tunnel
bridge signs=
upstream=Hanover Street Bridge
upstream signs=
downstream=Baltimore Harbor Tunnel
downstream signs=