A Drive through the Fort McHenry Tunnel, Baltimore, Maryland.

. By T.V. Antony Raj

On our way from Ellicott City, MD to North Brunswick, NJ we whisked down through the Fort McHenry Tunnel, a 7,200-foot-long, four-tube, 8-lane, bi-directional tunnel that carries Interstate I-95 traffic underneath the Baltimore Harbor, in Maryland. The tunnel crosses the Patapsco River, just south of Fort McHenry and connects the Locust Point and Canton areas of Baltimore City. The tunnel named for the nearby Fort McHenry, inspired Francis Scott Key to write anthem “The Star-Spangled Banner.“

The Fort McHenry Tunnel, the largest underwater highway tunnel, as well as the widest vehicular tunnel ever built by the immersed-tube method, opened on Saturday, November 23, 1985.

Opening day for the Baltimore Harbor 7,200-foot-long 8-lane Fort McHenry Tunnel, Saturday November 23, 1985. (Photo: roadstothefuture.com)

The following is an excerpt from “I-95 Drivers Get Remedy for Harbor Headache – Baltimore’s Fort McHenry Tunnel’s Debut Today is Expected to Ease Bottlenecks“, that appeared in The Washington Post, November 23, 1985.

“The new Baltimore is a nice place to live, but you would not want to visit – not if you are inching through the grimy Harbor Tunnel, that is. For interstate travelers, the dread begins miles away as they steel themselves for the maddening Harbor Tunnel bottleneck that often forms miles outside of Baltimore. But all that’s about to change. Travelers on I-95 who scarcely glimpse Baltimore’s restored town houses, its sparkling Inner Harbor or the growing downtown skyline will soon see a new side of the city as they whisk through its gleaming new Fort McHenry Tunnel. The new eight-lane tunnel – a massive $750 million engineering project 5 years in the making – will open today after a 3:00 PM ribbon cutting, lengthy ceremonies and special motorcades, just in time for the Thanksgiving travel crush. Dozens of state and federal dignitaries are expected to be on hand for the opening ceremonies today to claim credit for the largest underwater road project in the history of the Interstate highway system, one that came in under budget and almost on time.”

The Fort McHenry Tunnel, is a vital link in I-95, the East Coast’s most important interstate route, Interstate 95, between Maine and Florida. 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. Soon after, the nearby Baltimore Harbor Tunnel, a pair of two-lane road tunnels, southeast of downtown Baltimore, Maryland, and Interstate 895, opened to traffic in 1957, were closed for extensive repairs.

The Fort McHenry Tunnel has 8 lanes in 4 tubes and is 1.5 miles (2.4 km) with operating speed of variable up to 55 miles per hour (89 km/h). Each tunnel is 26 feet (7.9 m) wide with a tunnel clearance of 12.5 feet (3.8 m). The lowest elevation is at 107 feet (33 m) below harbor water surface.

Fort McHenry Tunnel – Project Plans

Profile View of Fort McHenry Tunnel

Typical Section View of Fort McHenry Tunnel

Here's what the east approach looked like when it was under construction in July 1983 — Here’s what the east approach looked like when it was under construction in July 1983. (Photo: roadstothefuture.com)

One of the eastbound tubes under construction, March 1984, near the mid-point under the harbor, about 100 feet below the surface of the water. (Photo: roadstothefuture.com)

Howard P. Foley Co. of Baltimore, was awarded the $47 million contract for mechanical and electrical equipment. It involved the installation of a 48 9-foot-diameter ventilation fans to move up to 6.7 million cubic feet of fresh air per minute into the tunnel and to exhaust fume-laden air out of the tunnel. 24 installed in the west ventilation building and 24 in the east ventilation building. In each ventilation building, 12 of the fans are for supply and 12 are for exhaust. Each ventilation building is equivalent to a small power substation for converting the voltage of the power coming into the tunnel complex.

Since the entire tunnel has continuous signal, lighting and surveillance systems, the tunnel complex has a very large system of electrical systems, with many hundreds of miles of wiring.

Firefighting equipment is stationed throughout the tunnel, with water mains serving the hydrants. The tunnel has 28 pumps with a total capacity of 44,000 gallons per minute.

The first 300 yards of each inbound portal simulates daylight with high intensity lighting and white pavement. This arrangement eliminates the “dark hole” effect that were on older tunnels and provides enough transition for the eyes of motorists to adjust from daylight to the lighting level inside the tunnel.

A part of the E-ZPass Tollgate (Photo: T.V. Antony Raj)

The I-95 construction through the City of Baltimore received 90% federal-aid funding from the U.S. Highway Trust Fund, for design, right-of-way and construction, with the remaining 10% coming from state funds.

Even in late-1970s, the state’s 10% share of the projected cost of the Fort McHenry Tunnel project was high. So, the state of Maryland and the City of Baltimore requested the Federal Highway Administration (FHWA) fund the whole 100% of the project’s cost.

The state of Maryland and the City of Baltimore requested the Federal Highway Administration (FHWA) to fund the whole 100% of the project’s cost. They also wanted tolls to be collected via a toll plaza built immediately east of the tunnel, at a cost of $27 million, to pay off the 10% share in installments.

The Tollgates in the 24 lanes at Fort McHenry Tunnel Toll Plaza collect a $2 toll from both directions of I-95. All lanes are E-ZPass compatible and allow commuters the ease of paying their tolls electronically. Some lanes are set aside for E-ZPass users only. This plaza is administered by the Maryland Transportation Authority.

Vital Facts about Fort McHenry Tunnel
Length	1.5 miles (2.4 km)
Highway class	Freeway, built to Interstate highway standards
Highway route	Interstate I-95
Water body crossed	Baltimore Harbor and shipping channel
Total number of lanes	8 lanes
Number of tubes	4
Number of lanes per tube	2 lanes
Roadway width per tube	26 feet (7.9 m) from curb to curb
Roadway vertical clearance	16 feet
Speed limit	Variable up to 55 mph
Toll facilities	Electronic tolling plus cash lanes, toll plaza in Canton
Toll	$2 for 2-axle vehicle, commuter discounts available
Pavement type	Asphalt (bituminous concrete)
Administrative agency for design, right-of-way and construction	Interstate Division for Baltimore City (IDBC)
Owner since opening	Maryland Transportation Authority (MdTA)
Design Prime Consultant	Sverdrup & Parcel and Parsons, Quade, Brinckerhoff & Douglas (joint venture)
Initial estimate of cost total for design, right-of-way and construction	$825 million
Contracting method	Agency public bid contracting, 11 construction contracts
Construction Began	May 7, 1980
Trench Tunnel Prime Contractor	Kiewit/Raymond/Tidewater (K-R-T)
West Approach Prime Contractor	Lane Construction Corporation
East Approach Prime Contractor	S. J. Groves & Sons Co.
Mechanical and Electrical Prime Contractor	Howard P. Foley Co.
Facility target date for completion	Early 1985
Final cost total for design, right-of-way and construction	$750 million
Funding method	100% Interstate highway federal-aid, with 10% to be repaid by state from toll revenue
Facility opened to traffic	November 23, 1985
Traffic Volumes as of December 2005	Average about 118,000 vehicles per day, 9% large trucks