Editing Hell Gate Bridge (section)

==== Bronx viaduct ====
In the Bronx, the Hell Gate Bridge has an approach viaduct measuring {{Convert|4356|ft|m}} long<ref name="RAG1914 p. 1368" /> and descends at a grade of up to 1.2 percent.<ref name="RAG1914 p. 1368" /><ref name="Ammann p. 1661" /> The NH used [[helper locomotive]]s during the 20th century to assist freight trains traversing the approach viaduct's grade.<ref name="p896297024" /><ref name="p879783320">{{cite magazine |date=October 23, 1943 |title=Five More Electric Locomotives Added to New Haven Fleet: Trend in design is to higher-horsepower single-cab units—newest type is suitable for freight and passenger service Table I—Principal Dimensions and Weights of the Three Latest Types of New York, New Haven & Hartford Electric Locomotives |magazine=Railway Age |page=655 |volume=115 |issue=17 |id={{ProQuest|879783320}}}}</ref> The Bronx viaduct merges with the former four-track [[Port Morris Branch]] (now the one-track [[Oak Point Link]]) at 142nd Street in Port Morris.<ref name="RAG1914 p. 889" /><ref>{{harvnb|Ammann|1918|ps=.|pages=1660–1661}}</ref> Separate ramps carry the western and eastern pairs of tracks down to the level of the Port Morris Branch.<ref name="RAG1914 p. 889" /> As built, the western ramp descended between the Port Morris Branch's western and eastern pairs of tracks, while the eastern ramp descended to the east of the Port Morris Branch.<ref name="Ammann p. 1660" /><ref name="RAG1914 p. 889" /> Two sets of piers carry the ramps northward from the Bronx Kill span to 132nd Street.<ref name="n142388040" />

From the Bronx Kill north to 132nd Street, the four-track-wide viaduct consists of plate girders, which rest on concrete piers. Each pier is less than {{Convert|50|ft}} tall and has an arched opening at the base.<ref name="RAG1914 p. 889" /> The Hell Gate Pathway runs underneath the arches.<ref name="The Hell Gate Pathway : NYC Parks 2006 n945" /> The viaduct splits into two ramps north of 132nd Street, each with space for two tracks.<ref name="RAG1914 p. 889" /> Between 132nd and 138th Street, the ramps are largely supported by rectangular concrete piers.<ref name="RAG1914 p. 889" /> The plate girders run parallel to each other, under the tracks, and are intersected perpendicularly by I-beams, which support the concrete-and-ballast trackbeds above.<ref name="RAG1915 p. 422">{{harvnb|Railway Age Gazette|1915|ps=.|page=422}}</ref> The western ramp crosses over the Port Morris Branch's former eastern pair of tracks from 132nd to 133rd Street and is supported by large steel cross-girders.<ref name="RAG1915 p. 422" /> Between 138th and 142nd streets, the line is carried on an embankment measuring {{Convert|900|ft}} long.<ref name="RAG1914 p. 889" />