Editing Sydney Harbour Bridge (section)

===Planning===
In 1914, [[John Bradfield (engineer)|John Bradfield]] was appointed Chief Engineer of Sydney Harbour Bridge and Metropolitan Railway Construction, and his work on the project over many years earned him the legacy as the father of the bridge.<ref name="pl-jb" /> Bradfield's preference at the time was for a [[cantilever bridge]] without piers, and in 1916 the [[New South Wales Legislative Assembly|NSW Legislative Assembly]] passed a bill for such a construction, however it did not proceed as the [[New South Wales Legislative Council|Legislative Council]] rejected the legislation on the basis that the money would be better spent on the war effort.<ref name=shb-archives37 />

Following [[World War I]], plans to build the bridge again built momentum.<ref name=culture.gov/> Bradfield persevered with the project, fleshing out the details of the specifications and financing for his cantilever bridge proposal, and in 1921 he travelled overseas to investigate tenders. His confidential secretary [[Kathleen M. Butler]] handled all the international correspondence during his absence, her title belying her role as project manager as well as a technical adviser.<ref>{{Cite news|date=28 February 1924|title=THE BRIDGE DESIGNER AND HIS SECRETARY|page=10|work=Sydney Morning Herald|url=http://nla.gov.au/nla.news-article16128932|access-date=28 December 2020|archive-date=24 September 2023|archive-url=https://web.archive.org/web/20230924095437/https://trove.nla.gov.au/newspaper/article/16128932|url-status=live}}</ref><ref>{{cite web|date=5 December 1924|title=International Woman Suffrage News|url=https://www.britishnewspaperarchive.co.uk/viewer/bl/0002219/19241205/038/0011|access-date=28 December 2020|via=[[British Newspaper Archive]]}}</ref> On return from his travels Bradfield decided that an arch design would also be suitable<ref name=shb-archives37 /> and he and officers of the NSW Department of Public Works prepared a general design<ref name=culture.gov /> for a single-arch bridge based upon [[New York City]]'s [[Hell Gate Bridge]].<ref name=bridging-sydney /><ref name=repaint-rta>{{cite web|url=http://www.rta.nsw.gov.au/roadprojects/resources/documents/permanent_panels/sydney_harbour_bridge.pdf|title=Sydney Harbour Bridge repainting|publisher=[[Roads & Traffic Authority]]|access-date=1 August 2011|archive-url=https://web.archive.org/web/20120713090933/http://www.rta.nsw.gov.au/roadprojects/resources/documents/permanent_panels/sydney_harbour_bridge.pdf|archive-date=13 July 2012|url-status=live}}</ref> In 1922 the government of [[George Fuller (Australian politician)|George Fuller]] passed the ''Sydney Harbour Act 1922'', specifying the construction of a high-level cantilever or arch bridge across the Harbour between Dawes Point and Milsons Point, along with construction of necessary approaches and electric railway lines,<ref name=shb-archives37 /> and worldwide [[Request for tender|tender]]s were invited for the project.<ref name=pl-jb />
[[File:Norman Selfe proposal for Sydney Harbour Bridge.jpg|thumb|left|[[Norman Selfe]]'s winning design at the second competition {{circa|1903}}]]
[[File:Hell Gate Bridge cricket.jpg|thumb|left|The [[Hell Gate Bridge]] in [[New York City]] inspired the final design of Sydney Harbour Bridge.]]
[[File:Opening_of_Tenders_(Sydney_Harbour_Bridge)_(6352488398).jpg|thumb|left|Opening of Tenders January 1924. l-r: Seated T. B. Cooper, R. T. Ball. Standing: J. J. C. Bradfield, Kathleen Butler, Mr. Swift.]]
As a result of the tendering process, the government received twenty proposals from six companies; on 24 March 1924 the contract was awarded to [[Dorman Long|Dorman Long & Co]] of [[Middlesbrough]], England well known as the contractors who later built the similar [[Tyne Bridge]] in [[Newcastle Upon Tyne]], for an arch bridge at a quoted price of [[Australian pound|AU£]]4,217,721 11s 10d.<ref name=pl-jb /><ref name=shb-archives37 /> The arch design was cheaper than alternative cantilever and [[suspension bridge]] proposals, and also provided greater [[Stiffness|rigidity]] making it better suited for the heavy loads expected.<ref name=shb-archives37 /> In 1924, Kathleen Butler travelled to [[London]] to set up the project office within those of Dorman, Long & Co., "attending the most difficult and technical questions and technical questions in regard to the contract, and dealing with a mass of correspondence".<ref>{{cite web|date=10 October 1924|title=The Vote|url=https://www.britishnewspaperarchive.co.uk/viewer/bl/0002186/19241010/008/0001|access-date=28 December 2020|via=[[British Newspaper Archive]]}}</ref>

Bradfield and his staff were ultimately to oversee the bridge design and building process as it was executed by Dorman Long and Co, whose Consulting Engineer, [[Ralph Freeman (1880-1950)|Sir Ralph Freeman]] of [[Douglas Fox (engineer)#Douglas Fox & Partners|Sir Douglas Fox and Partners]], and his associate Georges Imbault, carried out the detailed design and erection process of the bridge.<ref name=pl-jb /> Architects for the contractors were from the British firm [[John James Burnet|John Burnet & Partners]] of [[Glasgow]], Scotland.<ref name="glasgowsculpture"/> Lawrence Ennis, of Dorman Long, served as Director of Construction and primary onsite supervisor throughout the entire build, alongside Edward Judge, Dorman Long's Chief Technical Engineer, who functioned as Consulting and Designing Engineer.

The building of the bridge coincided with the construction of a system of underground railways beneath Sydney's CBD, known today as the [[City Circle]], and the bridge was designed with this in mind. The bridge was designed to carry six lanes of road traffic, flanked on each side by two railway tracks and a footpath. Both sets of rail tracks were linked into the underground [[Wynyard railway station, Sydney|Wynyard railway station]] on the south (city) side of the bridge by symmetrical ramps and tunnels. The eastern-side railway tracks were intended for use by a planned rail link to the [[Northern Beaches]];<ref>{{cite NSW HD|4800281|Wynyard Former Tram Tunnels|access-date=12 April 2019}}</ref> in the interim they were used to carry [[Trams in Sydney|trams]] from the North Shore into a terminal within Wynyard station, and when tram services were discontinued in 1958, they were converted into extra traffic lanes. The [[Bradfield Highway, Sydney|Bradfield Highway]], which is the main roadway section of the bridge and its approaches, is named in honour of Bradfield's contribution to the bridge.