The length of the longest span is 1,750' and the total length is 8,170' (1.5 mi.). It was designed by Ralph Modjeski, and, in 1991, it had an average daily traffic of 87,158. [Bridge Hunter] It claimed the "world's longest suspension bridge" title from the 1924 Bear Mountain Bridge, which had a navigation span of 1,632'.
Historic Bridges rates this bridge 10/10 for both national and local historic significance. Not too many bridges get a double-10.
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LC-DIG-highsm- 57137
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| DRPA posted The #BenFranklinBridge is lit red, white, and blue tonight in celebration of #IndependenceDay. Bridges Now and Then shared |
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| phillyroads (Figure by Paul Phillipe Cret and Rudolphe Modjeski.) The towers are 385' above mean high water and the foundations are up to 170' below. They provide a clearance of 135' and hold two cables, each of which are 30" in diameter and contain 18,666 wires. |
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| History's Mirror posted The Benjamin Franklin Bridge (Delaware River Bridge), Philadelphia (1926). Location: Philadelphia, Pennsylvania, and Camden, New Jersey Year: 1926 Description: Iconic steel suspension bridge connecting Philadelphia and Camden Key Features: 1. 2,917-foot length 2. 85-foot-wide roadway 3. Two 542-foot-tall steel towers 4. Suspension cables and towering arches Historic Context: 1. 1920s urbanization and industrial growth 2. Regional connectivity and economic development 3. Innovative engineering and architectural design Significance: 1. World's longest suspension bridge (1926-1929) [my emphasis] 2. Symbolized regional unity and progress 3. Facilitated transportation and commerce Interesting Facts: 1. $40 million construction cost (approx. $600 million today) 2. Designed by architect Paul Philippe Cret 3. Opened on July 1, 1926 4. Carries over 100,000 vehicles daily Legacy: 1. National Historic Civil Engineering Landmark (1986) 2. Iconic Philadelphia landmark 3. Representing engineering innovation and regional connectivity Sources: 1. American Society of Civil Engineers 2. Philadelphia Historical Commission 3. Delaware River Port Authority |
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| DRPA-rehabilitation via DRPA-ben-franklin |
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| Bridges Now and Then posted Philadelphia-Camden's Delaware River Bridge, renamed the Benjamin Franklin Bridge in 1955, is seen under construction, June 13, 1924. (Free Library of Philadelphia) |
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| Bridges Now and Then posted Building the Delaware River Bridge, later named the Ben Franklin Bridge, July 30, 1925. (The Franklin Institute) Dave Frieder: Engineer of design, Ralph Modjeski. Its cousin bridge is Manhattan bridge! |
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| Delaware River Port Authority - DRPA posted The Delaware River Bridge (later renamed the Ben Franklin Bridge) under construction in 1925. The bridge would open about a year later. This pic is looking at the main span from Camden. |
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| John Kathman commented on BN&T's post 1927 |
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| Byron Tinney posted Philadelphia |
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| Kevin Lagasse commented on Byron's post Benny in the lunch hour on July 11, 2023. Was getting onto I-95 North from Center City. Bryon Tinney: Kevin Lagasse my picture was taken from the top of that building to the right in your photo |
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| Steve Stern posted Ben Franklin Bridge - Philadelphia. |
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| Street View |
The anchorages on either side give the bridge an appearance of massiveness. Each of the granite anchorages to which the steel cables are attached covers three-quarters of an acre. The two anchorages, which together required 216,000 tons of masonry, rise 175 feet above the ground. Their "toeholds" sink into the earth 65 feet into the Philadelphia side, and 105 feet into the Camden side. [phillyroads]
So anchorages are like piers in that much of the work is below the surface. Cable-stay bridges don't need anchorages, but they probably do need taller towers. I wonder how the costs trade off.
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| Street View |
Most suspension bridges are deck trusses. The Williamsburg Bridge was a through truss. This bridge appears to be a pony truss where the truss does not have a top and the sides are both above and below the deck.
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| Street View |
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| 𝗥𝗲𝗺𝗲𝗺𝗯𝗲𝗿 𝗪𝗵𝗲𝗻: 𝗣𝗲𝗻𝗻𝘀𝘆𝗹𝘃𝗮𝗻𝗶𝗮 posted The beginnings of Ben Franklin Bridge during its construction (from the Philadelphia side), 1925! |
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| Delaware River Port Authority - DRPA posted #WaybackWednesday pic of the "Delaware River Bridge" looking east towards New Jersey at the middle of the center span on 9/8/1924. The bridge would later be renamed the Ben Franklin Bridge. Bridges Now and Then shared Dave Frieder: Engineer of design, Ralph Modjeski. This is a "Cousin" of the Manhattan bridge. |
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| Bridge Hunter [I tried two different web sites to get a higher resolution photo. Both were broken. I've noticed that the deck bends upwards when the cables have only a partial load.] |
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| Historic Philadelphia USA posted Delaware River Bridge construction, the Camden side span—Looking west, Philadelphia (1926) The construction of the Delaware River Bridge, later renamed the Ben Franklin Bridge, was a monumental engineering project in 1926. Spanning the river between Philadelphia and Camden, New Jersey, the bridge was one of the longest suspension bridges in the world at the time. This view from the Camden side shows the final stages of construction, as the massive steel spans were being completed. The bridge was a critical link between the two cities and played a key role in the growth of both regions. Its completion was celebrated with a grand opening on July 4, 1926, symbolizing progress and unity. |
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| Delaware River Port Authority - DRPA posted The first reel of wire used to construct the two main cables on the The Delaware River Bridge, later renamed the Ben Franklin Bridge. Each reel contained 100,000 feet of wire. Bridges Now and Then shared Dave Frieder: Each Cable is 30 Inches Diameter. Each Cable has 18,666 wires at 61 strands. 306 wires per strand. |
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