Editing Hell Gate Bridge (section)

=== Construction ===
{{multiple image
| align = right
| direction = vertical
| width = 220
| image1 = Hell Gate Bridge 1915 Arch Construction.JPG
| caption1 = Bridge under construction {{circa|1915}}
| image2 = Hell Gate Bridge ca 1917.png
| caption2 = Bridge seen {{circa|1917}}
}}

==== Initial contracts ====
Excavations for the Astoria end of the main span, across Hell Gate, commenced in March 1911,<ref name="n142367701" /><ref>{{Cite news |date=March 19, 1911 |title=New East River Bridge; To Connect Long Island and New England Railroads. |url=https://www.nytimes.com/1911/03/19/archives/new-east-river-bridge-to-connect-long-island-and-new-england.html |access-date=February 29, 2024 |work=The New York Times |issn=0362-4331 |archive-date=February 29, 2024 |archive-url=https://web.archive.org/web/20240229173842/https://www.nytimes.com/1911/03/19/archives/new-east-river-bridge-to-connect-long-island-and-new-england.html |url-status=live}}</ref> and were nearly completed by the end of the year.<ref name="n142371629" /> The [[American Bridge Company]] received a contract for the steelwork on the Hell Gate span, Wards Island viaduct, and Queens approach viaduct,<ref>{{Cite news |date=November 5, 1911 |title=Hell Gate Bridge |via=newspapers.com |url=https://www.newspapers.com/article/the-new-york-times-hell-gate-bridge/142373151/ |access-date=February 29, 2024 |work=The New York Times |issn=0362-4331 |pages=52 |postscript=none |archive-date=February 29, 2024 |archive-url=https://web.archive.org/web/20240229173852/https://www.newspapers.com/article/the-new-york-times-hell-gate-bridge/142373151/ |url-status=live}}; {{Cite news |date=November 9, 1911 |title=Pennsylvania-New Haven Link Construction Under Way |via=newspapers.com |url=https://www.newspapers.com/article/the-wall-street-journal-pennsylvania-new/142371684/ |access-date=February 29, 2024 |work=The Wall Street Journal |pages=8 |issn=0099-9660 |postscript=none |archive-date=February 29, 2024 |archive-url=https://web.archive.org/web/20240229173847/https://www.newspapers.com/article/the-wall-street-journal-pennsylvania-new/142371684/ |url-status=live}}; {{Cite news |date=November 4, 1911 |title=Big Contract Will Furnish Work Here |via=newspapers.com |url=https://www.newspapers.com/article/star-gazette-big-contract-will-furnish-w/142371656/ |access-date=February 29, 2024 |work=Star-Gazette |pages=2 |archive-date=February 29, 2024 |archive-url=https://web.archive.org/web/20240229173843/https://www.newspapers.com/article/star-gazette-big-contract-will-furnish-w/142371656/ |url-status=live}}</ref> while the McClintic-Marshall Company was hired to manufacture steel for the other parts of the bridge.<ref>{{Cite news |date=December 29, 1911 |title=P. R. R. Bridge Awards |via=newspapers.com |url=https://www.newspapers.com/article/the-brooklyn-daily-eagle-p-r-r-bridge/142378110/ |access-date=February 29, 2024 |work=The Brooklyn Daily Eagle |issn=2577-9397 |pages=5 |archive-date=February 29, 2024 |archive-url=https://web.archive.org/web/20240229192728/https://www.newspapers.com/article/the-brooklyn-daily-eagle-p-r-r-bridge/142378110/ |url-status=live}}</ref> The [[Carnegie Steel Company]] was hired in early 1912 to roll the steel plates for the bridge.<ref>{{Cite news |date=February 3, 1912 |title=Awarded Hell Gate Work; Transportation of Bridge Material a Big Problem for Carnegie Co. |url=https://www.nytimes.com/1912/02/03/archives/awarded-hell-gate-work-transportation-of-bridge-material-a-big.html |access-date=February 29, 2024 |work=The New York Times |issn=0362-4331 |postscript=none |archive-date=February 29, 2024 |archive-url=https://web.archive.org/web/20240229192720/https://www.nytimes.com/1912/02/03/archives/awarded-hell-gate-work-transportation-of-bridge-material-a-big.html |url-status=live}}; {{Cite news |date=February 1, 1912 |title=Slight Lull in Steel Market but Producers Are Optimistic |via=newspapers.com |url=https://www.newspapers.com/article/the-wall-street-journal-slight-lull-in-s/142377238/ |access-date=February 29, 2024 |work=The Wall Street Journal |pages=2 |issn=0099-9660 |archive-date=February 29, 2024 |archive-url=https://web.archive.org/web/20240229192724/https://www.newspapers.com/article/the-wall-street-journal-slight-lull-in-s/142377238/ |url-status=live}}</ref> Later that year, Patrick Ryan, the Manhattan Bridge's main contractor, received a $2 million{{Efn-lr|About ${{Inflation|index=US-GDP|start_year=1912|value=2|fmt=c}} million in {{Inflation/year|US-GDP}}{{Inflation/fn|US-GDP|group=lower-alpha}}}} contract to build the bridge's foundation,<ref>{{Cite news |date=September 22, 1912 |title=Hell Gate Viaduct; $2,000,000 Contract Awarded for New East River Bridge. |url=https://www.nytimes.com/1912/09/22/archives/hell-gate-viaduct-2000000-contract-awarded-for-new-east-river.html |access-date=February 29, 2024 |work=The New York Times |issn=0362-4331 |archive-date=February 29, 2024 |archive-url=https://web.archive.org/web/20240229192720/https://www.nytimes.com/1912/09/22/archives/hell-gate-viaduct-2000000-contract-awarded-for-new-east-river.html |url-status=live}}</ref> while John A. Gray received a contract to complete [[Geotechnical investigation|test borings]] for the bridge.<ref>{{Cite news |date=October 6, 1912 |title=New Bridge Work Let; Ready to Make Test Borings for East River Structures. |url=https://www.nytimes.com/1912/10/06/archives/new-bridge-work-let-ready-to-make-test-borings-for-east-river.html |access-date=February 29, 2024 |work=The New York Times |issn=0362-4331 |archive-date=February 29, 2024 |archive-url=https://web.archive.org/web/20240229192721/https://www.nytimes.com/1912/10/06/archives/new-bridge-work-let-ready-to-make-test-borings-for-east-river.html |url-status=live}}</ref> Masonry contracts were awarded to Patrick Ryan (who partnered with [[United States Realty and Construction Company|U.S. Realty]] to build the Hell Gate spans' towers<ref>{{cite web |date=November 16, 1918 |title=Sues for Bridge Profits; Patrick Ryan Says Company, as Partner, Kept $375,000 from Him. |url=https://www.nytimes.com/1918/11/16/archives/sues-for-bridge-profits-patrick-ryan-says-company-as-partner-kept.html |access-date=March 2, 2024 |website=The New York Times |issn=0362-4331 |archive-date=March 2, 2024 |archive-url=https://web.archive.org/web/20240302205742/https://www.nytimes.com/1918/11/16/archives/sues-for-bridge-profits-patrick-ryan-says-company-as-partner-kept.html |url-status=live}}</ref>), as well as Arthur McMullin and T. A. Gillespie.<ref name="p128359243">{{Cite magazine |date=August 1, 1913 |title=Progress on the Hell Gate Bridge |magazine=Concrete – Cement Age |page=92 |volume=3 |issue=2 |id={{ProQuest|128359243}}}}</ref> Harold W. Hudson was the chief construction engineer.<ref name="p1257139268">{{cite news |date=January 17, 1943 |title=Colonel Hudson Dies; Engineer Built Bridges: Triborough and Hell Gate Construction Chief Was Officer in World War Bridge Engineer |work=New York Herald Tribune |issn=1941-0646 |page=40 |id={{ProQuest|1257139268}} |postscript=none}}; {{Cite news |date=January 16, 1943 |title=Col. H. W. Hudson, Bridge Engineer; Chief in the Construction of Triborough and Hell Gate Spans – Dies at 67 |url=https://www.nytimes.com/1943/01/16/archives/col-hw-hudson-bridge-engineer-chief-in-the-construction-of.html |access-date=March 4, 2024 |work=The New York Times |issn=0362-4331 |archive-date=March 4, 2024 |archive-url=https://web.archive.org/web/20240304021950/https://www.nytimes.com/1943/01/16/archives/col-hw-hudson-bridge-engineer-chief-in-the-construction-of.html |url-status=live}}</ref>

Work formally commenced on the Bronx and Queens approach viaducts in July 1912, and work on the foundations of the main span's towers began that September,<ref name="p128359243" /><ref name="nyt-1913-07-06">{{Cite news |date=July 6, 1913 |title=Hell Gate Bridge Will Boom Realty; Demand for Factory Sites Adjacent to Approaches on Both Sides of the East River. |url=https://www.nytimes.com/1913/07/06/archives/hell-gate-bridge-will-boom-realty-demand-for-factory-sites-adjacent.html |access-date=February 29, 2024 |work=The New York Times |issn=0362-4331 |archive-date=February 29, 2024 |archive-url=https://web.archive.org/web/20240229210726/https://www.nytimes.com/1913/07/06/archives/hell-gate-bridge-will-boom-realty-demand-for-factory-sites-adjacent.html |url-status=live}}</ref> though no above-ground work had commenced.<ref name="nyt-1912-11-10">{{Cite news |date=November 10, 1912 |title=Hell Gate Structure Now Being Built Will Be an Important Link in the System of the Connecting Railroad That Will Change the Relation of Manhattan Island to the Mainland for Commercial Ends. |url=https://www.nytimes.com/1912/11/10/archives/hell-gate-structure-now-being-built-will-be-an-important-link-in.html |access-date=February 29, 2024 |work=The New York Times |issn=0362-4331 |archive-date=February 29, 2024 |archive-url=https://web.archive.org/web/20240229210727/https://www.nytimes.com/1912/11/10/archives/hell-gate-structure-now-being-built-will-be-an-important-link-in.html |url-status=live}}</ref> By October 1912, workers were preparing to lower [[Caisson (engineering)|caissons]] for the main span's Wards Island tower,<ref>{{Cite news |date=October 26, 1912 |title=Building Piers for the Connecting Railroad |via=newspapers.com |url=https://www.newspapers.com/article/times-union-building-piers-for-the-conne/142374282/ |access-date=February 29, 2024 |work=Times Union |pages=3 |archive-date=February 29, 2024 |archive-url=https://web.archive.org/web/20240229192726/https://www.newspapers.com/article/times-union-building-piers-for-the-conne/142374282/ |url-status=live}}</ref> as the underlying layer of rock was over {{Convert | 100 | ft | spell = in}} deep and was covered by layers of sand, coarse gravel, and boulders.<ref name="RAG1914 p. 891" /> Twenty-one caissons were used to excavate the Wards Island tower's foundation.<ref name="RAG1914 p. 891" /><ref name="n142398010">{{Cite news |date=January 4, 1914 |title=Connecting Railway Takes Definite Form |via=newspapers.com |url=https://www.newspapers.com/article/the-brooklyn-daily-eagle-connecting-rail/142398010/ |access-date=February 29, 2024 |work=The Brooklyn Daily Eagle |issn=2577-9397 |pages=40 |archive-date=February 29, 2024 |archive-url=https://web.archive.org/web/20240229225305/https://www.newspapers.com/article/the-brooklyn-daily-eagle-connecting-rail/142398010/ |url-status=live}}</ref> The caissons were larger and deeper than those used in the construction of the [[tallest buildings in New York City]] at the time.<ref name="n142439586" /> The caisson-sinking process was further complicated by the discovery of a diagonal fissure in the underlying rock.<ref name="n142439586" /><ref name="p556427259">{{cite news |date=January 21, 1917 |title=World's Heaviest Bridge Now Spans Hell Gate Tides |via=newspapers.com |url=https://www.newspapers.com/article/new-york-herald-worlds-heaviest-bridge/142456914/ |access-date=March 1, 2024 |work=New York Herald |page=45 |issn= |id= |archive-date=March 1, 2024 |archive-url=https://web.archive.org/web/20240301200610/https://www.newspapers.com/article/new-york-herald-worlds-heaviest-bridge/142456914/ |url-status=live}}</ref> It ultimately took seven months to sink the caissons and ensure that the tower would not be susceptible to [[Settlement (structural)|settlement]].<ref name="n142439586">{{Cite news |date=September 26, 1915 |title=Great Hell Gate Bridge Triumph of Engineering |via=newspapers.com |url=https://www.newspapers.com/article/the-sun-great-hell-gate-bridge-triumph-o/142439586/ |access-date=March 1, 2024 |work=The Sun |pages=26 |archive-date=March 1, 2024 |archive-url=https://web.archive.org/web/20240301165227/https://www.newspapers.com/article/the-sun-great-hell-gate-bridge-triumph-o/142439586/ |url-status=live}}</ref>

In November 1912, a [[New York Supreme Court]] justice [[Injunction|enjoined]] the contractors from erecting abutments on Wards Island.<ref>{{cite news |date=November 9, 1912 |title=Enjoin Building of Bridge at Hell Gate |work=The Hartford Courant |page=10 |issn=1047-4153 |id={{ProQuest|555947937}} |postscript=none}}; {{Cite news |date=November 9, 1912 |title=Blocks Ward's Island Bridge |via=newspapers.com |url=https://www.newspapers.com/article/the-sun-blocks-wards-island-bridge/142379647/ |access-date=February 29, 2024 |work=The Sun |pages=3 |archive-date=February 29, 2024 |archive-url=https://web.archive.org/web/20240229192716/https://www.newspapers.com/article/the-sun-blocks-wards-island-bridge/142379647/ |url-status=live}}</ref><ref name="n142379738" /> The operators of the [[Manhattan Psychiatric Center]] claimed that patients would be disturbed by loud noises, both during construction and after the bridge opened,<ref name="n142379738" /> but the city government claimed that the hospital's lease of the island had expired.<ref>{{Cite news |date=November 26, 1912 |title=Doctors in Way of Connecting Railroad |via=newspapers.com |url=https://www.newspapers.com/article/times-union-doctors-in-way-of-connecting/142380787/ |access-date=February 29, 2024 |work=Times Union |pages=8 |archive-date=February 29, 2024 |archive-url=https://web.archive.org/web/20240229192717/https://www.newspapers.com/article/times-union-doctors-in-way-of-connecting/142380787/ |url-status=live}}</ref> The injunction was lifted in January 1913,<ref>{{Cite news |date=January 17, 1913 |title=Bridge Work to Proceed |via=newspapers.com |url=https://www.newspapers.com/article/the-brooklyn-daily-eagle-bridge-work-to/142394242/ |access-date=February 29, 2024 |work=The Brooklyn Daily Eagle |issn=2577-9397 |pages=26 |postscript=none |archive-date=February 29, 2024 |archive-url=https://web.archive.org/web/20240229225258/https://www.newspapers.com/article/the-brooklyn-daily-eagle-bridge-work-to/142394242/ |url-status=live}}; {{Cite news |date=January 17, 1913 |title=Wards Island Is to Be Bridged |via=newspapers.com |url=https://www.newspapers.com/article/times-union-wards-island-is-to-be-bridge/142394265/ |access-date=February 29, 2024 |work=Times Union |pages=14 |archive-date=February 29, 2024 |archive-url=https://web.archive.org/web/20240229225259/https://www.newspapers.com/article/times-union-wards-island-is-to-be-bridge/142394265/ |url-status=live}}</ref> when the State Supreme Court ruled that the law permitting the bridge's construction overrode the law that restricted railroads above the grounds of a hospital.<ref name="n142388040">{{Cite news |date=January 26, 1913 |title=Great New Bridge Over River Within Two Years |via=newspapers.com |url=https://www.newspapers.com/article/the-brooklyn-daily-eagle-great-new-bridg/142388040/ |access-date=February 29, 2024 |work=The Brooklyn Daily Eagle |issn=2577-9397 |pages=13 |archive-date=February 29, 2024 |archive-url=https://web.archive.org/web/20240229211220/https://www.newspapers.com/article/the-brooklyn-daily-eagle-great-new-bridg/142388040/ |url-status=live}}</ref>

==== Pier construction ====
The construction of piers on Randalls and Wards Islands and in Queens began in February 1913.<ref name="p128359243" /> [[Derrick]]s were used to construct the concrete piers under the Bronx Kill, Randalls Island, Little Hell Gate, and Wards Island spans. The foundations of the Bronx Kill span's piers were constructed using caissons, since the underlying layer of rock was nearly {{Convert | 100 | ft}} deep.<ref name="n142439586" /> The foundations of the Little Hell Gate span's piers were built in open [[cofferdam]]s due to the shallowness of that strait.<ref name="RAG1914 pp. 889–890">{{harvnb|Railway Age Gazette|1914|ps=.|pages=889–890}}</ref> The contractor built a dock on Wards Island to load and unload material. Derricks carried solid materials from the dock to a conveyor belts, which in turn led to covered storage bins, while cement was poured down a chute to a cement house next to the storage bins. Sand, stone, and cement from the bins were dumped into "charging cars" and carried to a mixing plant, where the material was mixed into concrete.<ref name="RAG1914 p. 890" /> Elevators were used to transport concrete to the top of each pier.<ref name="nyt-1913-07-06" /><ref name="n142388040" />

By July 1913, some of the piers and retaining walls for the Bronx and Queens viaducts had been constructed, and contractors had installed temporary plants on Randalls and Wards Islands.<ref name="nyt-1913-07-06" /><ref>{{cite news |date=July 3, 1913 |title=New York Connecting Railroad: Work on New Four-track Line to Begin This Summer-- Road to Cost $30,000,000. |work=The Wall Street Journal |page=7 |issn=0099-9660 |id={{ProQuest|129418454}}}}</ref> The next month, the PRR and NH announced that the NYCR would issue a $30 million mortgage and $11 million in bonds{{Efn-lr|The mortgage would be about ${{Inflation|index=US-GDP|start_year=1913|value=30|fmt=c}} million, while the bonds would be ${{Inflation|index=US-GDP|start_year=1913|value=30|fmt=c}} million in {{Inflation/year|US-GDP}}{{Inflation/fn|US-GDP|group=lower-alpha}}}} to fund the construction of the Hell Gate Bridge and associated lines;<ref>{{Cite news |date=August 27, 1913 |title=New York Connecting Road Seeks Bond Issue |via=newspapers.com |url=https://www.newspapers.com/article/the-wall-street-journal-new-york-connect/142395390/ |access-date=February 29, 2024 |work=The Wall Street Journal |pages=5 |issn=0099-9660 |archive-date=February 29, 2024 |archive-url=https://web.archive.org/web/20240229225309/https://www.newspapers.com/article/the-wall-street-journal-new-york-connect/142395390/ |url-status=live}}</ref> the railroads had spent $8.6 million{{Efn-lr|About ${{Inflation|index=US-GDP|start_year=1913|value=8.6|fmt=c}} million in {{Inflation/year|US-GDP}}{{Inflation/fn|US-GDP|group=lower-alpha}}}} to date on the bridge.<ref>{{cite news |date=September 18, 1913 |title=New York Connecting Railway's New Financing |work=The Christian Science Monitor |page=17 |issn=0882-7729 |id={{ProQuest|193288095}}}}</ref> The bonds were issued later that year.<ref>{{cite news |date=November 15, 1913 |title=N.Y. Connecting Railroad Bond Issue Approved.: Public Service Board Permits Immediate Issue of $11,000,000 Bonds Under the $30,000,000 Mortgage Proceeds to Take Care of Short Term Notes |work=The Wall Street Journal |page=5 |issn=0099-9660 |id={{ProQuest|129431137}} |postscript=none}}; {{Cite news |date=November 21, 1913 |title=Connecting R.R. Bonds; $11,000,000 4 1–2 Per Cent. Issue Quickly Taken at 94 1–2. |url=https://www.nytimes.com/1913/11/21/archives/connecting-rr-bonds-11000000-4-12-per-cent-issue-quickly-taken-at.html |access-date=February 29, 2024 |work=The New York Times |issn=0362-4331 |archive-date=February 29, 2024 |archive-url=https://web.archive.org/web/20240229225258/https://www.nytimes.com/1913/11/21/archives/connecting-rr-bonds-11000000-4-12-per-cent-issue-quickly-taken-at.html |url-status=live}}</ref> During a site visit in mid-1914, a local civic group noted that a temporary span had been finished across Bronx Kill and that piers were being built within the riverbed of Little Hell Gate.<ref>{{Cite news |date=May 12, 1914 |title=Report on Progress of Hell Gate Bridge |via=newspapers.com |url=https://www.newspapers.com/article/the-brooklyn-daily-eagle-report-on-progr/142399884/ |access-date=February 29, 2024 |work=The Brooklyn Daily Eagle |issn=2577-9397 |pages=4 |postscript=none |archive-date=February 29, 2024 |archive-url=https://web.archive.org/web/20240229225310/https://www.newspapers.com/article/the-brooklyn-daily-eagle-report-on-progr/142399884/ |url-status=live}}; {{Cite news |date=May 13, 1914 |title=Long Island News |via=newspapers.com |url=https://www.newspapers.com/article/times-union-long-island-news/142399934/ |access-date=February 29, 2024 |work=Times Union |pages=8 |archive-date=February 29, 2024 |archive-url=https://web.archive.org/web/20240229225307/https://www.newspapers.com/article/times-union-long-island-news/142399934/ |url-status=live}}</ref> The main span's towers had reached the height of the deck by the end of 1914, while almost all of the other piers had been completed by then.<ref name="n142397488">{{Cite news |date=December 27, 1914 |title=Make Big Progress on Connecting Road |via=newspapers.com |url=https://www.newspapers.com/article/the-brooklyn-daily-eagle-make-big-progre/142397488/ |access-date=February 29, 2024 |work=The Brooklyn Daily Eagle |issn=2577-9397 |pages=59 |archive-date=February 29, 2024 |archive-url=https://web.archive.org/web/20240229225308/https://www.newspapers.com/article/the-brooklyn-daily-eagle-make-big-progre/142397488/ |url-status=live}}</ref>

==== Steelwork and completion ====
Steel girders and plates for the Little Hell Gate and Bronx Kill spans were being installed by late 1914.<ref name="n142397488" /> The girders under the two center tracks were installed first. Afterward, the center tracks were laid, and a derrick car and a [[Crane (rail)|locomotive crane]] were placed on opposite spans. The derrick car delivered girders that had already been riveted together, and the locomotive crane installed the girders for the outer tracks.<ref name="RAG1915 pp. 422–423">{{harvnb|Railway Age Gazette|1915|ps=.|pages=422–423}}</ref> The arched main span above Hell Gate was technically challenging because Hell Gate was a navigable waterway, and the arch could not be constructed using [[falsework]].<ref name="RAG1914 p. 890" /><ref name="Ammann p. 1663" /> Consequently, massive temporary backstays were built behind both of the Hell Gate towers to [[cantilever]] the two pieces of the arch.<ref name="n142439586" /><ref name="RAG1915 pp. 423–424">{{harvnb|Railway Age Gazette|1915|ps=.|pages=423–424}}</ref><ref name="n142439289">{{Cite news |date=October 9, 1915 |title=Queens Borough |via=newspapers.com |url=https://www.newspapers.com/article/brooklyn-life-queens-borough/142439289/ |access-date=March 1, 2024 |work=Brooklyn Life |pages=24 |archive-date=March 1, 2024 |archive-url=https://web.archive.org/web/20240301165225/https://www.newspapers.com/article/brooklyn-life-queens-borough/142439289/ |url-status=live}}</ref> To accommodate the backstays, the tops of the towers and some adjacent piers could not be completed until after the Hell Gate span was finished.<ref name="RAG1915 pp. 423–424" /><ref name="n142447894">{{Cite news |date=September 30, 1915 |title=Hell Gate Spans Quarter Inch Apart |via=newspapers.com |url=https://www.newspapers.com/article/the-brooklyn-daily-eagle-hell-gate-spans/142447894/ |access-date=March 1, 2024 |work=The Brooklyn Daily Eagle |issn=2577-9397 |pages=15 |archive-date=March 1, 2024 |archive-url=https://web.archive.org/web/20240301185856/https://www.newspapers.com/article/the-brooklyn-daily-eagle-hell-gate-spans/142447894/ |url-status=live}}</ref> After the backstays were constructed, movable derricks were installed atop the backstays.<ref name="RAG1915 p. 424">{{harvnb|Railway Age Gazette|1915|ps=.|page=424}}</ref>

One thousand workers and 40 engineers began installing the steelwork of the arch in November 1914;<ref name="n142448178">{{Cite news |date=July 20, 1915 |title=Biggest Bridge Half Finished |via=newspapers.com |url=https://www.newspapers.com/article/times-union-biggest-bridge-half-finished/142448178/ |access-date=March 1, 2024 |work=Times Union |pages=12 |archive-date=March 1, 2024 |archive-url=https://web.archive.org/web/20240301185854/https://www.newspapers.com/article/times-union-biggest-bridge-half-finished/142448178/ |url-status=live}}</ref> many of the laborers were [[Mohawk people|Mohawk]] Native American ironworkers from Quebec and upstate New York.<ref name="n142958279">{{Cite news |last=Minthorn |first=David |date=August 18, 2002 |title=Exhibit celebrates Mohawks' high-rise feats |via=newspapers.com |url=https://www.newspapers.com/article/star-gazette-exhibit-celebrates-mohawks/142958279/ |access-date=March 8, 2024 |work=Star-Gazette |pages=28 |archive-date=March 8, 2024 |archive-url=https://web.archive.org/web/20240308205902/https://www.newspapers.com/article/star-gazette-exhibit-celebrates-mohawks/142958279/ |url-status=live}}</ref> Work proceeded in two sections from either shore toward the middle of Hell Gate.<ref name="n142448178" /><ref name="p136977172">{{Cite magazine |date=October 13, 1915 |title=The Longest Steel Arch in the World |magazine=Outlook |page=346 |id={{ProQuest|136977172}}}}</ref> The main span consisted of 23 panels,<ref name="n142448178" /> which were installed by the derricks atop the backstays.<ref name="RAG1915 p. 424" /> The panels were composed of steel pieces that weighed as much as {{convert|185|ST|LT t}}.<ref name="p502726608" /><ref name="RAG1915 p. 423" /> The steel pieces were manufactured off-site<ref name="p556427259" /> and, at the time, were among the heaviest steel pieces ever manufactured.<ref name="n142410167">{{Cite news |last=Sewell |first=Edward Alden |date=October 10, 1915 |title=The Hell Gate Arch Becomes a Bridge |via=newspapers.com |url=https://www.newspapers.com/article/new-york-tribune-the-hell-gate-arch-beco/142410167/ |access-date=March 1, 2024 |work=New-York Tribune |issn=1941-0646 |pages=30 |archive-date=March 1, 2024 |archive-url=https://web.archive.org/web/20240301165226/https://www.newspapers.com/article/new-york-tribune-the-hell-gate-arch-beco/142410167/ |url-status=live}}</ref> Each piece was delivered to the site via car floats, then transported up via derricks.<ref name="RAG1915 p. 424" /> To counteract sagging caused by the weight of the panels, both halves of the bridge occasionally had to be adjusted.<ref name="n142439586" /> The project as a whole was declared half-finished in July 1915.<ref name="n142448178" /> The last pieces of the lower chord were installed during the week of September 28 to October 4, 1915,<ref name="p879810718">{{Cite magazine |date=November 5, 1915 |title=Progress on the Hell Gate Bridge |magazine=Railway Age Gazette |page= |pages=865, 867 |volume=59 |issue=19 |id={{ProQuest|879810718}}}}</ref><ref>{{cite news |date=October 4, 1915 |title=Hell Gate Bridge: President Rea Congratulates the Engineer on the Completion of the Span |work=The Wall Street Journal |page=3 |issn=0099-9660 |id={{ProQuest|129466847}}}}</ref> and both halves were officially joined on October 1.<ref name="p556427259" /><ref name="p548523866">{{cite news |date=October 1, 1915 |title=Ends of Hell Gate Bridge Joined: Big Steel Arch is Longest in the World |work=The Hartford Courant |page=17 |issn=1047-4153 |id={{ProQuest|548523866}}}}</ref> The gap between the two parts of the arch was just {{convert|5/16|in}}.<ref name="p556427259" /><ref name="p879810718" /> The extreme precision was attributed to the level of detail in the engineering drawings,<ref name="n142447894" /> as well as the use of highly precise surveying tools made by the [[W. & L. E. Gurley Company]].<ref>{{Cite news |date=April 11, 1994 |title=Gurley company was once the Tiffany of surveying tools |via=newspapers.com |url=https://www.newspapers.com/article/democrat-and-chronicle-gurley-company-wa/142946127/ |access-date=March 8, 2024 |work=Democrat and Chronicle |pages=13 |archive-date=March 8, 2024 |archive-url=https://web.archive.org/web/20240308180813/https://www.newspapers.com/article/democrat-and-chronicle-gurley-company-wa/142946127/ |url-status=live}}</ref>

The completion of the arch made the Hell Gate span the longest steel arch in the world.<ref name="p548523866" /><ref name="p136977172" /> The hydraulic jacks were removed from the towers,<ref name="n142410167" /> and the backstays were disassembled and reused in the approach viaducts.<ref name="n142439289" /><ref name="p879810718" /> Workers began driving 400,000 rivets into the arched span;<ref name="p879810718" /> Lindenthal claimed that they were among the largest rivets ever used.<ref name="p556427259" /> Due to cold weather, the upper chord of the arch could not be riveted together until May 1916.<ref name="p556427259" /> Locomotive cranes constructed the remaining portions of the viaducts.<ref name="In 2024 q032" /> By mid-October 1916, the PRR and NH anticipated that passenger service would commence at the beginning of 1917.<ref name="nyt-1916-10-15">{{Cite news |date=October 15, 1916 |title=New Hell Gate Bridge; To be Opened to Traffic Early in January, 1917. |url=https://www.nytimes.com/1916/10/15/archives/new-hell-gate-bridge-to-be-opened-to-traffic-early-in-january-1917.html |access-date=February 29, 2024 |work=The New York Times |issn=0362-4331 |archive-date=February 29, 2024 |archive-url=https://web.archive.org/web/20240229225258/https://www.nytimes.com/1916/10/15/archives/new-hell-gate-bridge-to-be-opened-to-traffic-early-in-january-1917.html |url-status=live}}</ref> Finishing touches were placed on the bridge during late 1916.<ref>{{Cite magazine |date=December 29, 1916 |title=A Review of Bridge Construction |magazine=Railway Age Gazette |pages=1165 |volume=61 |issue=26 |id={{ProQuest|886551104}}}}</ref> In total, the bridge cost $18.5 million.{{efn-lr|About ${{Inflation|index=US-GDP|start_year=1916|value=18.5|fmt=c}} million in {{Inflation/year|US-GDP}}{{Inflation/fn|US-GDP|group=lower-alpha}}}}<ref>{{harvnb|Ammann|1918|ps=.|page=1662}}</ref> Before the bridge's official opening, police forces patrolled it to prevent sabotage during World War I.<ref>{{cite news |date=February 5, 1917 |title=City Bridges Guarded by Naval Militia: Details Patrol the East River—machine Guns on Piers Water Supply System Watched Raids by Cranks Are Feared-secret Squads Protect Subway Naval Battalion Men on Guard on City's Bridges |work=New-York Tribune |issn=1941-0646 |page=1 |id={{ProQuest|575678692}} |postscript=none}}; {{Cite news |date=February 8, 1917 |title=Police May Relieve the National Guard; Special Service at Public Works Is Being Continued, However, by the State |url=https://www.nytimes.com/1917/02/08/archives/police-may-relieve-the-national-guard-special-service-at-public.html |access-date=March 1, 2024 |work=The New York Times |issn=0362-4331 |archive-date=March 1, 2024 |archive-url=https://web.archive.org/web/20240301200606/https://www.nytimes.com/1917/02/08/archives/police-may-relieve-the-national-guard-special-service-at-public.html |url-status=live}}</ref>