Wednesday, May 29, 2019

1909 Manhattan Bridge over the East River in NYC, NY

(Bridge Hunter; Historic Bridges, rates 10 and 10; HAERNYCroadsDave Frieder Photos3D Satellite)

Arthur Overdijk posted
New York

Obviously, the above image was cropped from the following.
History Daily photo
The Manhattan Bridge under construction, 1909.
Mike Breski shared

It's not the Brooklyn Bridge, but it does look like it was the second bridge I checked: Manhattan Bridge.
Photo from HAER NY,31-NEYO,164--1 from ny0980

1. VIEW LOOKING TOWARDS MANHATTAN WITH BROOKLYN BRIDGE ON RIGHT - Manhattan Bridge, Spanning East River at Flatbush Avenue, between New York City & Brooklyn, New York County, NY

[It looks like the World Trade Towers are still standing on the left.]
This single span suspension bridge contains one of the longest suspension spans in the U.S., and had the largest carrying capacity in the country when it was built. It is unusual in that it was designed as a dual-level bridge; carrying street-cars on the upper level and subway tracks on the lower, with roadways in the center of each level. The approaches to the bridge were designed by Carrere and Hastings, and incorporated allegorical figures of Manhattan and Brooklyn by Daniel Chester French, which have since been removed to the Brooklyn Museum. [HAER]

1910 Postcard via Bridge Hunter

One of the important design considerations concerning suspension bridges is anchoring the suspension cables.
Photo taken by Geoff Hubbs in March 2019, License: Released into public domain

NYCroads
Original cross-section of the roadway on the Manhattan Bridge. (Figure by Paul Phillipe Cret and Rudolphe Modjeski.)
[The lower rails were for subways and the upper rails were for streetcars.]
The subway traffic hastened the deterioration of the bridge because the concentrated load of a train twisted the deck. Over a half-billion dollars was spent during the 1990s and 2000s to reconstruct the deck. It had already been reconfigured from four streetcar and four vehicle lanes to seven vehicle lanes. Each streetcar level carries two lanes and the center part now carries three reversible lanes. And, of course, the vehicles are no longer horse&buggies. [NYCroads]

Fred Hadley posted four photos with the comment:
One feature of the Manhattan Bridge, under construction in 1908, which has attracted much attention in and called for considerable comment is the apparently light construction, and the certainly light appearance of the towers. This is noticeable if they are compared with the massive ma­sonry towers of the adjoining Brooklyn Bridge, or the bulky and very inartistic towers of the Williams­burg Bridge farther up the river. 
As a matter of fact, the Manhattan Bridge towers are of particularly strong and stiff construction. The weight is carried on four closed, plate-steel, box columns, which rise uninterruptedly from base to top. 
They are built of heavy plating, upon the cellular system, heavy trans­verse diaphragms running throughout the full height of each tower, and assisting to give the required amount of cross-sectional area of steel and the necessary stiff­ness, to prevent distortion by buckling under the heavy loads imposed. 
To preserve the four legs in the true vertical position and resist all tendency to displacement by wind pressure, the whole of which on the full length of the bridge will be communicated to and must be resisted by the towers, each pair of legs is heavily braced together by transverse trussing. In addition to this, each pair of legs, as thus braced, is strongly tied together at the top, at the mid-height, and at the level of the floor system by massive truss­ing and knee bracing.
Traffic will be carried upon two decks, and the bridge will accommodate four rapid transit tracks, four surface tracks, one 35-foot roadway, and two ll-foot footwalks. Construction work was commenced in 1901, and, as we have said, it will be completed toward the close of 1909.
Scientific American excerpt, April 10, 1909
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