This 2000 photo shows the Triborough Bridge suspension span (I-278) heading from Queens toward the Bronx, prior to reconstruction. The deck on the main suspension span was replaced between 2002 and 2004. (Photo by Jim K. Georges.)
 

NOT ONE BRIDGE, BUT MANY: The Triborough Bridge is not simply a single span, but rather is a complex comprised of three long-span bridges, a number of smaller bridges and viaducts, fourteen miles of approach highways and parkways, parks and recreational facilities, and administrative offices for the Triborough Bridge and Tunnel Authority. To appreciate the magnitude of the project, it can only be viewed in its entirety from above.
 

Plans for connecting Manhattan, Queens and the Bronx were first announced by Edward A. Byrne, chief engineer of the New York City Department of Plant and Structures, in 1916. While its construction had been long recommended by local officials, the Triborough Bridge did not receive any funding until 1925, when the city appropriated funds for surveys, test borings and structural plans.

By that time, alternative plans had surfaced from Gustav Lindenthal, who did not want to spoil the view of his nearby Hell Gate Bridge. Instead of constructing what he called a "suspension bridge of cheap pole and washline architecture," Lindenthal suggested adding a second deck to his Hell Gate railroad bridge to carry five lanes of automobile traffic. The alternative plan also called for two spurs: one to East 102nd Street to provide direct access to Central Park, and another at East 116th Street. While he did not immediately call for a spur at East 125th Street - he believed that the area was already too congested - one was planned for construction at a later date.

PICKING UP WHERE THE STOCK MARKET CRASH LEFT OFF: On October 25, 1929, Mayor Jimmy Walker broke ground on the Triborough Bridge. This date later proved significant, as it was just one day after the "Black Thursday" that helped trigger the Great Depression. The initial $5.4 million allocated by New York City for construction of the new bridge - most of which went to condemnation awards and counsel fees - had already been spent before the Ward's Island piers had been built.

With its coffers depleted by the ensuing Depression, the city abandoned work on the bridge early in 1930. That summer, President Herbert Hoover created the Reconstruction Finance Corporation (RFC). At the suggestion of Mayor Walker, Senator Robert Wagner applied for a $37 million to construct the Triborough Bridge. However, Joseph McKee, a fiscal conservative who took over as acting mayor when Walker left under a cloud of investigation, blocked the RFC application because he considered it a confession of municipal bankruptcy.

Work on the Triborough Bridge was at a standstill through 1932, when New York City Parks Commissioner Robert Moses persuaded Governor Al Smith to resume its construction. Moses sought a way for Bronx and Westchester residents to reach his Long Island parks without driving through Manhattan streets. He planned to construct new approaches - the Grand Central Parkway, the East River Drive, the Major Deegan Expressway and Southern (Bruckner) Boulevard - to the bridge from all three boroughs. When he asked the original project's chief engineer where the approaches were to be built, he was surprised to hear that no such plans had been developed.

At that time, Moses was busy constructing parkways throughout the rest of New York City and Long Island. In the belief that the Triborough Bridge was essential to maintain a unified parkway system, Moses sought permission to control the independent agency charged with construction of the bridge.

In 1933, Mayor Fiorello LaGuardia appointed Moses as the chairman of the Triborough Bridge Authority. President Franklin D. Roosevelt granted the new authority a $37 million loan, making the bridge the first project in New York City to earn approval from the new Federal-level Public Works Administration (PWA). Seeking a clear break from the Tammany Hall corruption of the past, LaGuardia said the following to the press:

We are going to build a bridge instead of patronage. We are going to pile up stone and steel instead of expenses. We are going to build a bridge of steel, and spell steel "s-t-e-e-l" instead of "s-t-e-a-l." The people of the City of New York are going to pay for that bridge, and they are going to pay for it in tolls after its completion.

Before construction on the Triborough Bridge resumed, Moses employed the services of famed bridge designer Othmar Ammann. At that time, Ammann had held the position of chief engineer at the Port of New York Authority for seven years.
 

LEFT: The Triborough Bridge suspension span between Queens and Ward's Island, as shown under construction in 1934. (Photo by New York State Department of Parks and Historic Preservation.) RIGHT: Work continues on hoisting the deck and installing the suspending cables in 1935. (Photo by Triborough Bridge and Tunnel Authority.)
 

THE SUSPENSION SPAN: The original plans for the Triborough (Hell Gate) suspension span were devised by Arthur I. Perry under the direction of the New York City Department of Plant and Structures. Two steelwork towers that recalled the dual-arched Gothic design of the Brooklyn Bridge towers, and four suspension cables were to support a dual-deck, 16-lane roadway.
 

When Ammann took over the design of the bridge, he tried to employ as much of Perry's design as possible while cutting costs considerably. The redesign eliminated one deck, leaving a single eight-lane, truss-stiffened deck. The two 5,500-ton steel towers were redesigned to allow for the scaled-back dimensions, but were fitted into the already constructed foundations. Finally, two suspension cables were to be used for the single roadway deck. Ammann's redesign saved at least $10 million from original cost estimates.
 

Although he used a 20-foot-deep stiffening truss throughout the structure, Ammann utilized a series of 96-foot-long (the width between trusses) plate girders that functioned as floor beams. The raising of the trussed deck began at each tower and proceeded simultaneously toward midspan and the approach roads. The roadway is tucked between the top and bottom chords of the stiffening trusses, partially obscuring the view for motorists. However, pedestrians and cyclists enjoy an unobstructed view along walkways cantilevered over the water from the top chord of the stiffening trusses.

The towers reflected newer design and construction conventions than those originally proposed by Perry. Simple geometry and uncluttered lines characterized Ammann's new design. The four 93-foot vertical posts between the legs of the towers are strictly ornamental. (These posts are held in place by a horizontal strut at mid-height.) The tops of the towers, as with the ornamental lightposts on the bridge, reflected the Art Deco skyscraper aesthetics of the era. All tower sections were fabricated off-site, and were hoisted into place by a single crane at each site.
 

The Hell Gate suspension span of the Triborough Bridge, as shown in this 1941 photo looking toward Astoria, Queens. (Photo by Library of Congress, Prints and Photographs Division, Marion Post Wolcott Collection, LC-USF33-031252-M5.)
 

THE LIFT SPAN: Moses originally proposed that the Manhattan arm of the Triborough Bridge be constructed at East 103rd Street so as to avoid the mental institutions on Randall's Island. Hw also believed that the East 103rd Street would provide a convenient alternative to the Queensboro Bridge, which was operating at its design capacity. However, the East 125th Street location that was previously procured for the Triborough Bridge was used instead. Moses said of the location as follows:
 

A tough problem was the 125th Street Manhattan arm of the crossing. Any child could see that it belonged much further downtown, at 103rd Street, in a direct line with Queens. This would have avoided disruption of the Randall's Island institutions. But the same forces, namely, the Hearst publishing and real estate interests that had procured the 125th Street arm in the first place, would probably have stymied the whole project if we had insisted on 103rd Street. We reluctantly accepted 125th Street, on the theory that a misplaced arm is better than no bridge at all.

The single-deck lift span over the Harlem River between Manhattan and Randall's Island is actually comprised of three independent truss spans. The main span, a 310-foot-long movable central truss span, has a fixed clearance of 55 feet, but can be raised to a position 135 feet above the Harlem River. The movable deck hangs from the two 210-foot-high towers, whose design borrows from that of the George Washington Bridge, by 96 wire ropes wound around 15-foot-diameter drums. Flanking the movable deck are two 230-foot-long fixed truss spans.

With six traffic lanes and two sidewalks, the Harlem River lift span has a weight of 2,200 tons and a deck area of 20,000 square feet, making it the largest such bridge in the world when it opened. However, it was not the heaviest, thanks to Ammann's efforts to reduce its weight (and thereby its cost). For example, instead of paving the roadway with concrete, his design had asphalt planks laid atop steel-plate, road-deck girders.

THE TRUSS SPAN: Between the Bronx Kills separating Randall's Island from the Port Morris section of the Bronx, Ammann designed a three-span steel truss bridge that carries eight lanes of traffic over a single deck. In its permanently fixed position, the Bronx Kills truss span provides 55 feet of vertical clearance. Because the Bronx Kills was not navigable, the Navy ruled that the span could be built as a fixed structure, but only if it were built so that its central span could be converted into a lift span if the Kills were ever made navigable. (In subsequent years, however, much of the Bronx Kills has been filled in with parkland.)
 

The fixed truss span of the Triborough Bridge over the Bronx Kills, as shown in this 1941 photo looking toward the toll plaza. (Photo by Library of Congress, Prints and Photographs Division, Marion Post Wolcott Collection, LC-USF33-031252-M2.)
 

THE PLAZA AND APPROACHES: The toll plaza and approaches were an engineering feat unto themselves. In the plaza proper, where 22 lanes of traffic converge from the north, south and west, a roadway area of 390,000 square feet (approximately nine acres) is supported by 1,700 concrete columns, and is faced on all sides by a concrete wall 8,000 feet long. The plaza, which is as large as a railroad switchyard, contains 70,000 cubic yards of concrete and 5,900 tons of reinforcing steel, more than that used in the towers of the suspension span. It is surrounded by two concentric circular ramps designed to eliminate grade crossings and left turns, as well as to safe, efficient movements inside the toll plaza.
 

More than two and one-half miles of viaduct connecting the three spans to the boroughs, as well as to each other, were constructed. The viaducts are supported by steel-plate girders that rest on concrete piers 60 to 140 feet apart. Steel I-beams and cross-breams were overlaid with concrete slabs section-by-section.

THE MAGNITUDE OF THE COMPLEX: The following excerpt from Robert A. Caro's The Power Broker provides some scope into the Triborough Bridge project:

Here was a project to kindle the imagination… In size, its proportions were heroic. For all Moses' previous construction feats, it dwarfed any other single enterprise he had undertaken. Its approach ramps would be so huge that houses - not only single-family homes but also sizable apartment buildings - would have to be demolished by the hundreds to give them footing. Its approaches, the masses of concrete in which its cables would be embedded, would be as big as any pyramid built by an Egyptian Pharaoh, its roadways wider than the widest roadways built by the Caesars of Rome. To construct those anchorages and to pave those roadways (just the roadways of the bridge proper itself, not the approach roads) would require enough concrete to pave a four-lane highway from New York to Philadelphia, enough to reopen Depression-shuttered cement factories from Maine to the Mississippi. To make the girders on which that concrete would be laid, Depression-banked furnaces would have to be fired up at no fewer than fifty separate Pennsylvania steel mills. To provide enough lumber for the forms into which that concrete would be poured, an entire forest would have to crash on the Pacific Coast on the opposite side of the American continent… Triborough was not really a bridge at all, but four bridges which, together with 13,500 feet of broad viaducts, would link together three boroughs and two islands.

Triborough was not a bridge so much as a traffic machine, the largest ever built. The amount of human energy that would be expended in its construction gives some idea of its immensity: more than five thousand men would be working at the site, and these men would be putting into place the materials furnished by the labor of many times five thousand men; before the Triborough Bridge was completed, its construction would have generated more than 31,000,000 man-hours of work in 134 cities in twenty states. And the size of the bridge is also shown by the amount of money involved. With $5,400,000 already contributed by the city and $44,200,000 promised by the PWA (Public Works Administration), the amount promised for its construction was almost equal to the combined cost of all the projects Robert Moses had built on Long Island during the previous ten years.

In an average month, about 1,000 construction workers were at the site of the Triborough Bridge. However, in the months leading to the July 1936 deadline, the number of construction workers swelled to about 2,800.
 

A motorcade led by President Franklin D. Roosevelt opens the Harlem River lift span in this 1936 photo. (Photo by New Deal Network.)
 

"The Triborough is not just a bridge nor yet a crossing. It is a great artery, connecting three boroughs of the city, and reaching out at its borders into adjacent counties and states. It is not merely a road for automobiles and trucks, but a general city improvement, reclaiming dead areas and providing for residence along its borders, esplanades, play facilities, landscaping and access to the great new parks." - Robert Moses (1936)
 

OPENING A NEW ERA OF ARTERIAL ACCESS: The Triborough Bridge opened on July 11, 1936 at a cost of $60.3 million. The new Triborough Bridge Authority, which had its administrative offices at the Randall's Island toll plaza, financed $35 million of the construction costs. The bonds were backed by 25-cent tolls. Federal, state and city outlays financed the remainder of the costs.

More than 15,000 invited guests were at the dedication ceremony, at which President Franklin Roosevelt, Mayor LaGuardia and Commissioner Moses spoke. Moses made the following remarks at the opening ceremony:

This is a city of unparalleled natural advantages, most of which have been neglected. We have never lacked plans. What we have lacked is elbow grease and execution.

New York is an old community. Dig down anywhere and you will find the relics and mementos of the early white settlers of the country - old coins, pipes, substructures and all the evidences of city growth and change.

Every plot of land has a history, structural, financial and legal. Every new project runs into endless difficulties and obstacles, the most serious of which can never be anticipated. It is for this reason that our planners and the men and women of vision carry their enterprises beyond the shelves of libraries and the forgotten files of newspapers.

There is literally nothing new in New York. Everything has been thought of at one time or another and for every successful accomplishment, there are scores who claim the paternity for themselves and their ancestors. I have heard from not less than a hundred people in the past week, all claiming recognition for one or another person as the inventor of the Triborough Bridge and demanding everything from the re-christening of the bridge to a dozen good tickets to the ceremony.

In the last decade, we have really begun to tackle the problems of this city and to make it livable, attractive and accessible. In reclaiming the natural beauties of our waterfronts, in opening up the avenues by which this great metropolis, which has justly been called insular, can establish contact with the rest of the country.

The Triborough is one of these great new arteries. It will soon be joined by the West Side Development, the Henry Hudson Parkway, the Marine Parkway, the completed Long Island parkway system, the Circumferential Boulevard (Belt Parkway), the East River (FDR) Drive and other great undertakings.

The Triborough is not just a bridge nor yet a crossing. It is a great artery, connecting three boroughs of the city, and reaching out at its borders into adjacent counties and states. It is not merely a road for automobiles and trucks, but a general city improvement, reclaiming dead areas and providing for residence along its borders, esplanades, play facilities, landscaping and access to the great new parks.

During the first year of operation in 1937, approximately 30,000 vehicles per day passed through the Triborough Bridge complex. In the late 1960's, the toll plaza and interchange at Randall's Island were both reconstructed to accommodate ever-increasing traffic volumes.
 

This 1999 photo shows the Triborough Bridge suspension span from Astoria Park in Queens. (Photo by Steve Anderson.)
 

THE LINCHPIN OF AN EXPANDING NETWORK: Moses intended the Triborough Bridge to serve as a crucial link not only in the New York City transportation network, but also between the Long Island state parks and the rest of the U.S. mainland. Almost immediately after the bridge opened, tens of thousands of vehicles jammed the Grand Central Parkway en route to Jones Beach. With congestion building on the Triborough Bridge and its approaches, Moses immediately advanced construction on the Bronx-Whitestone Bridge.
 

The Hell Gate and Bronx Kills spans received the I-278 designation in June 1958. For a brief period in late 1958, a southerly extension of the I-87 designation was proposed for the span; I-87 was to continue south along the Brooklyn-Queens Expressway. This proposal was dropped in early 1959.

CURRENT AND FUTURE IMPROVEMENTS: According to the New York State Department of Transportation (NYSDOT), the entire Triborough Bridge complex carries approximately 200,000 vehicles per day (AADT) between Queens, Manhattan and the Bronx. The Hell Gate and Bronx Kills spans of the Triborough Bridge are part of I-278, the only road that runs through all five boroughs. The two Hell Gate and Bronx Kills spans carry eight lanes of traffic between the Bronx and Queens, while the Harlem River span "spur" carries six lanes of traffic to 125th Street in Manhattan via Randall's Island.

In 1997, MTA Bridges and Tunnels began a long-term, $550 million program to rehabilitate the Triborough Bridge. The project, which is scheduled for completion in 2009, is divided into the following three phases:

 

The engineering design firm Ammann and Whitney, which was contracted for the reconstruction project, determined that the most efficient alternative for replacing the decks was to utilize different designs for different deck sections. An orthotropic deck will be used for the suspension span, a precast deck will be used for the lift and truss spans, and precast concrete panels will be used for viaduct and approach sections. More than 1.6 million square feet of deck will be replaced in this project.

Other sub-projects include the replacing steel and concrete on the approaches, dehumidifying the anchorages, re-anchoring additional strands, fitting seismic dampers, replacing the existing steel median and side with concrete ("Jersey") barriers, and installing new variable message signs.
 

This 1999 photo shows the Triborough Bridge suspension span at sunset. The Manhattan skyline looms in the background. (Photo by John Anderson.)
 

Construction started:
Opened to traffic:
Total length of approaches (Manhattan-Queens-Bronx):
Cost of original structure:

EAST RIVER SUSPENSION BRIDGE (I-278)

Length of main span:
Length of each side span:
Length, anchorage to anchorage:
Width of bridge:
Number of traffic lanes:
Height of towers above mean high water:
Clearance at center above mean high water:
Steel used in towers:
Steel used in suspended structure:
Reinforcing steel used in deck:
Number of cables:
Diameter of each of two cables:
Length of each cable:
Diameter of each cable:
Total number of wires per cable:
Total length of wires:
Weight of cables and suspenders:
Concrete used in anchorages:
Concrete used on bridge roadway:

HARLEM RIVER LIFT BRIDGE
(WEST WYE-NYSDOT REFERENCE ROUTE:  900G)

Length of main lift-truss span:
Length of each side truss span:
Length, anchorage to anchorage:
Height of towers:
Clearance of lift span above mean high water:
Clearance of lift span in raised position:
Number of traffic lanes:
Steel used in lift span:
Steel used in side spans and towers:

BRONX KILLS CROSSING (I-278)

Length of main truss span:
Length of approach truss span:
Length, anchorage to anchorage:
Clearance of truss span above mean high water:
Number of traffic lanes:
Steel used in main truss:
Steel used in approach truss span:
Concrete used in piers:

WARD'S ISLAND VIADUCT

Structural steel used:
Reinforcing steel used:
Concrete used in roadway and piers:

RANDALL'S ISLAND INTERCHANGE

Reinforcing steel used:
Concrete used in roadway and piers:
Roadway area:
 

October 25, 1929
July 11, 1936
13,820 feet
$60,300,000



1,380 feet
700 feet
2,780 feet
98 feet
8 lanes
315 feet
143 feet
5,500 tons
10,000 tons
17,030 tons
2 cables
20¾ inches
3,104 feet
0.196 inch
9,176 wires
10,800 miles
3,315 tons
133,500 cubic yards
5,600 cubic yards




310 feet
230 feet
770 feet
210 feet
55 feet
135 feet
6 lanes
2,050 tons
4,300 tons



383 feet
1,217 feet
1,600 feet
55 feet
8 lanes
3,000 tons
6,000 tons
13,900 cubic yards



29,500 tons
5,500 tons
117,500 cubic yards



9,500 tons
111,200 cubic yards
390,000 square feet