Seven Hills Flyover | NSW Environment & Heritage

Culture and heritage

Heritage

Seven Hills Flyover

Item details

Name of item: Seven Hills Flyover
Type of item: Built
Group/Collection: Transport - Rail
Category: Railway Bridge/ Viaduct
Primary address: Main West corridor Between Seven Hills and Blacktown Stations, Seven Hills, NSW 2147
Parish: Prospect
County: Cumberland
Local govt. area: Blacktown

Boundary:

10 metres at all directions from the structure.
All addresses
Street AddressSuburb/townLGAParishCountyType
Main West corridor Between Seven Hills and Blacktown StationsSeven HillsBlacktownProspectCumberlandPrimary Address
Near Federal RoadSeven HillsBlacktown  Alternate Address

Owner/s

Organisation NameOwner CategoryDate Ownership Updated
RailCorpState Government 
RailCorpState Government 
RailCorpState Government 

Statement of significance:

Seven Hills flyover is of local significance as evidence of the Post-War quadruplication of the rail network between Seven Hills and Blacktown during 1946-1955. It demonstrates the organisation of railway crossovers and circulation of trains with limited interruptions to the railway transport operations for the provision of fast service trains in the metropolitan network. Seven Hills flyover was the first use of this type of structure on the NSW railways with landmark quality in the railwayscape and provides evidence of railway design and engineering at the time of its construction in 1946.
Date significance updated: 04 Oct 13
Note: The State Heritage Inventory provides information about heritage items listed by local and State government agencies. The State Heritage Inventory is continually being updated by local and State agencies as new information becomes available. Read the OEH copyright and disclaimer.

Description

Designer/Maker: NSW Department of Railways
Builder/Maker: NSW Department of Railways
Construction years: 1954-1955
Physical description: FLYOVER (1954)
The flyover is a two span highly skewed underbridge carrying a single electrified track (Richmond Down Line). The 21.3 metre spans are over the Up Suburban, Up Main and Down Suburban Lines. The superstructure comprises riveted steel main through girders connected by riveted steel cross girders. The two main girders are continuous over the central pier. The cross girders support a reinforced concrete ballast trough with upturned edges to retain ballast. The deck is waterproofed with 19mm thick asphalt. A 63mm thick concrete topping exists for waterproofing protection. The abutments and wing walls are brick, and the central pier is constructed of brick and concrete.
Physical condition and/or
Archaeological potential:
The bridge appears to be maintained in a good condition structurally as it remains in use. However, it may need some painting and cleaning due to graffiti. Corrosion and some concrete spalling may also exist.
Date condition updated:09 Apr 09
Modifications and dates: 1990s - some painting
Further information: The readily available research, history and comparative analysis do not indicate that this Flyover is of state significance.
Current use: Flyover
Former use: Nil

History

Historical notes: The Main Western line between Parramatta and Blacktown was opened in 1860 and duplicated in 1886. Quadruplication of the line through Seven Hills was one part of a much larger scheme to increase the number of tracks to four main lines between Lidcombe and St. Marys during World War II in order to provide maximum track capacity to the American ammunition and general store built at Ropes Creek. Only the easiest parts of the project were completed before the end of World War II in 1945. The section of quadruplicated track beyond Seven Hills was opened in 1955. It took over 32 years until all aspects of the quadruplication were completed between Westmead and Blacktown. Quadruplication reached St. Marys in 1978, while the Granville to Westmead section was finally completed in 1986.

The Seven Hills flyover was constructed in 1946 as part of the quadruplication between Seven Hills and Blacktown during 1946 -1955.

All traces of railway infrastructure at Seven Hills dating prior to 1955 have been removed except the flyover. The Department of Railways created a problem for itself when it decided to facilitate cross-platform passenger transfers at Parramatta station in order to allow passengers to detrain from a fast, non-stopping train from Sydney and walk across Platform 2/3 into an all-stations train for intermediate stations between Parramatta and Blacktown. These all-station trains also proceeded to Richmond. Because of the cross-platform arrangements, it was necessary to abandon the conventional arrangement whereby quadruplicated track was configured in a 'down/up/down/up' order. In this case it was essential to arrange tracks in a 'down/down/up/up' order. The result of this was the need to cross Richmond-bound trains over one Sydney-bound track. While grade crossings are widely used, the use of a flyover avoids the necessity of affected trains to stop while Richmond trains cross one Sydney-bound track. The Seven Hills flyover is 1.97 kms long and is earth-filled, except for a riveted plate girder underbridge that is fixed above the main tracks.

Flyovers are used in many different applications and exist at Central, Strathfield, Granville, Westmead, Sydenham, Wolli Creek, Unanderra, Dombarton, Demondrille, Bethungra, Waratah, Sandgate, Antiene and Cougal.

Historic themes

Australian theme (abbrev)New South Wales themeLocal theme
3. Economy-Developing local, regional and national economies Technology-Activities and processes associated with the knowledge or use of mechanical arts and applied sciences Locomotive design and technological development-
3. Economy-Developing local, regional and national economies Transport-Activities associated with the moving of people and goods from one place to another, and systems for the provision of such movements Building the railway network-

Assessment of significance

SHR Criteria a)
[Historical significance]
Seven Hills flyover is significant in demonstrating the organisation of railway crossovers and circulation of trains with limited interruption to the railway transport operations and provision of fast service in the metropolitan network during the 20th Century. The flyover was constructed in 1946 as part of the quadruplication between Seven Hills and Blacktown during 1946 -1955. It was the first use of this type of structure on the NSW railways.
SHR Criteria c)
[Aesthetic significance]
Seven Hills flyover is a typical steel riveted plate girder underbridge that is fixed above the main tracks with the remainder of the 1.97 kms long flyover earth-filled. It has a landmark quality in the railwayscape but limited aesthetic significance.
SHR Criteria e)
[Research potential]
The steel riveted plate girder underbridge have some potential to add to the knowledge of the post-war railway flyovers infrastructure, however; it is unlikely to yield information that is not available elsewhere.
SHR Criteria f)
[Rarity]
The flyover is not a rare example of such railway infrastructure. There are at least 18 similar flyovers in NSW.
SHR Criteria g)
[Representativeness]
Seven Hills flyover is a representative example of steel flyovers that were constructed after post-war period as part of the quadruplication of the railway network.
Integrity/Intactness: The flyover is intact.
Assessment criteria: Items are assessed against the PDF State Heritage Register (SHR) Criteria to determine the level of significance. Refer to the Listings below for the level of statutory protection.

Recommended management:

1. Conservation principles: Conserve cultural heritage significance and minimise impacts on heritage values and fabric in accordance with the ‘Australia ICOMOS Charter for Places of Cultural Significance’. 2. Specialist advice: Seek advice from a qualified heritage specialist during all phases of a proposed project from feasibility, concept and option planning stage; detailed design; heritage approval and assessment; through to construction and finalisation. 3. Documentation: Prepare a Statement of Heritage Impact (SOHI) to assess, minimise and prevent heritage impacts as part of the assessment and approval phase of a project. Prepare a Conservation Management Plan (CMP) prior to proposing major works (such as new additions, change of use or proposed demolition) at all places of State significance and all complex sites of Local significance. 4. Maintenance and repair: Undertake annual inspections and proactive routine maintenance works to conserve heritage fabric in accordance with the ‘Minimum Standards of Maintenance & Repair’. 5. Movable heritage: Retain in situ and care for historic contents, fixtures, fittings, equipment and objects which contribute to cultural heritage significance. Return or reinstate missing features or relocated items where opportunities arise. 6. Aboriginal, archaeology and natural heritage: Consider all aspects of potential heritage significance as part of assessing and minimising potential impacts, including Aboriginal, archaeology and natural heritage. 7. Unidentified heritage items: Heritage inventory sheets do not describe or capture all contributory heritage items within an identified curtilage (such as minor buildings, structures, archaeology, landscape elements, movable heritage and significant interiors and finishes). Ensure heritage advice is sought on all proposed changes within a curtilage to conserve heritage significance. 8. Recording and register update: Record changes at heritage places through adequate project records and archival photography. Notify all changes to the Section 170 Heritage & Conservation Register administrator upon project completion.

Listings

Heritage ListingListing TitleListing NumberGazette DateGazette NumberGazette Page
Heritage Act - s.170 NSW State agency heritage registerRailcorp S170 Register    

Study details

TitleYearNumberAuthorInspected byGuidelines used
S170 Heritage & Conservation Register Update2009 City Plan Heritage  Yes

References, internet links & images

TypeAuthorYearTitleInternet Links
WrittenC.C. Singleton1963Centenary of the Opening of the Western Line to Penrith, ARHS Bulletin, Vol. 14 No. 303, January
WrittenCC. Singleton1960Centenary of the Opening of the Western Line to Blacktown
WrittenRailCorp2006Seven Hills Flyover Bridges and Structures Integrity Report

Note: internet links may be to web pages, documents or images.

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Data source

The information for this entry comes from the following source:
Name: State Government
Database number: 4800175


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