HISTORY
The
history of metal road bridges is also the history of settlement and
communication in Victoria. The origin of many of the main trunk road routes can
be traced back to the period of exploration and pioneer settlement. The tracks
of explorers and squatters- Hume, Mitchell, Henty became the main roads, and
the fords over rivers became the sites of settlements and bridges.
In
this process, order was implemented by the Darling regulations which determined
the direction and form of surveys as Colonial government was imposed.
The
pioneering routes were from Melbourne to
Macedon/Kyneton, Geelong, Portland, and the Sydney Road(s), Omeo, and
around the bay. The very first track in Melbourne was formed by foot traffic
between the initial settlement near Batman’s Hill, and the wharf at the
pool or turning basin. The first bridge in the Port Phillip District was along
this route over the Elizabeth Street creek in 1838.
The
first Sydney Road followed the ridge near Deep Creek avoiding the boggy clay
soils near the Merri Creek. The present direct route between the creeks had the
advantage of not requiring any creek crossings before the Divide.
The
Port Fairy to Portland route was blazed by Edward Henty
in 1839, following the coast and crossing the
rivers at their mouths. This subsequently became the ‘Old Coach
Road’ later to be superseded by an inland route once bridges were
erected. The prosperity (or at least the legal administration) of the Western
District was intrinsically tied to Melbourne so that the Geelong-Melbourne
route was also well established by the 1830s.
By
1837 there were several established tracks in the Port Phillip District. The
Sydney track has been discussed, others included:
·
Melbourne
to Bulla, Sunbury and Macedon;
·
Melbourne
to the Maribyrnong at the Solomon’s Ford and then to Geelong;
·
Geelong
to Bacchus Marsh and Sunbury
By
1845 these had been augmented by new tracks to outlying areas including:
·
Melbourne
around the bay to Sorrento
·
Macedon
to Kyneton
·
Geelong
to Portland via the Princes Highway route
·
Geelong
to Portland via the Midland, Glenelg and Henty Highways
·
Albury
south to Omeo and Alberton
By
1855 the Gold Rushes had caused these routes to be further extended and a
network of cross-country routes connecting them. The principle goldfield routes
continued to focus on Melbourne and other port towns, as the route of diggers
and supplies to the gold fields. The route west from Melbourne to Ballarat was
pushed through to the South Australian border and a track had been finally cut
through the forests and morasses to Gippsland (O’Connor 1985:93).
Probably
the most important determinant of the location of bridges was the pre-existence
of an existing river crossing at either a ford or a punt.
Punts
operated across the Yarra in the late 1830s, William Watts operated one east of
Swanston Street in April 1838. Hodgson’s punt, which used a fixed wire
cable to haul it across the river, replaced this in 1839. This later became the
site of the first permanent bridge in Melbourne and demonstrates a common link
between punt and bridge, the Melbourne Bridge Company having taken over the
lease for the punt before erecting its bridge. A similar relationship existed with
Lynch's Punt and Bridge at Footscray.
The
early specification of river crossings as sites for towns by the Surveyor
General demonstrates that they were not simply ad hoc developments, but in at
least some cases were expressly planned in recognition of the needs of
travellers.
The
preponderance of towns with ford in their name is just one indication of their
importance in the development of settlement and maintenance of communication.
Broadford, Batesford, Fyansford, Guildford, Exford, Shelford, etc.
David
Lennox’s Return of Public Works (Port Phillip Government Gazette pp
984-986) provides us with the best
summary of the bridges that were constructed in the colony by the government
between the beginning of 1846 and end of 1850, prior to the Gold Rushes.
Whilst
no metal bridges were constructed in this period, the summary does provides us
with an indication of the priorities for allocating government expenditure; the
important routes; and the more substantial bridges that were constructed. They
included 17 bridges on Sydney Road, six on the Mount Macedon Road, four each on
the upper and lower Portland Roads and eight others.
Not
included here are the privately constructed bridges of the period, such as the
Melbourne Bridge Company’s Balbirnie’s bridge which spanned the
Yarra from 1845 to the opening of Lennox’s bridge in 1851.
The
most substantial bridgework by far, was Princes Bridge, with a single stone
arch span of 150 feet and a total length of 250 feet. The expenditure on this
alone was £19,000 compared with the total Roads and Bridges expenditure
of £31,474. This was the first major ‘permanent’ bridge built
in the Port Phillip District, all other bridges were of Timber (Cannon
1991:110).
The first Princes Bridge
lasted about 30 years before the demands of river widening, increasing road
traffic, and in particular the installation of cable tramways in
Melbourne’s streets, required a new bridge to be erected. The Government
commissioned David Munro to build a large stone and iron bridge on the same site at
a cost of £140,000. Designers were John H, Grainger, father of the famous composer and Charles D’Ebro. With the new bridge the opportunity was also taken to
straighten and widen the approach roads, making a far grander entrance to the
city. The new (current) Princes Bridge as it was christened, was opened to
traffic in 1888 (Cannon 1991:117).
On Merri Creek north of Melbourne on eof the
critical factors in Melbournes Bridge development was found to be the effect of
massive floods washing away the low level timber bridges. A stone and timber
bridge was erected by contractor Thomas Stephens in 1853-4, assisted in the design by the Inspector of Works
of the new Victorian Roads and Bridges Department Thomas Edwin Rosson. Rosson later identified the success of the bridge design
in withstanding floods in the wide spacing of the piles allowing debris to be
swept through instead of jamming (Cannon 1995; Allan 1939:77-81).
Rosson gave evidence to
the Victorian Legislative council Select Committee on Roads and Bridges in
1852, outlining his views of flood proofing bridges and constructing more
cheaply by using Tasmanian timber or even local blue gum, which would enable a
bridge costing about £2,000, as opposed to £10,000 for a
single-span stone bridge. He also suggested that iron girder bridges would be
more suitable for flat land, but did not recommend suspension bridges because
of danger resulting for use by cattle - presumably the fear of falling from
your horse on the slippery surface caused by their fouling the deck (Cannon
1991:118-9).
A ford on the Moonee Ponds Creek at the end of
Flemington Road near the Flemington Inn was initially replaced in 1839 by
primitive log crossing constructed by James Patrick Main then reconstructed in
1849 with £200 allocated by Lennox. According to Cannon, it was rebuilt
as a laminated timber arch at a cost of £492 although an 1851 Sketch by
Jarrett, shows it as a as a conventional log pile and beam bridge, while Max
Lay notes that it was not a site suitable for an arch bridge. An 1869 report in
the Argus describes it as a tumbledown collection of logs.
The timber bridge was replaced with a more
substantial cast and wrought iron bridge in 1868. This was to the design of G.
Francis incorporating
several rows of cast iron columns, each bolted together from two metre long
sections and supporting riveted wrought iron girders. It was subsequently
maintained by the government and provided a route to the Mt. Alexander
District, and a reasonable alternative Sydney route for when Sydney Road became
impassable in winter. Although reconstructed several times to incorporate a
wide concrete deck on concrete piers, the present bridge retains six rows of
cast iron columns, and some of the riveted wrought iron girders (Cannon 1995).
The inconvenience of the natural ford, meant
that the punts at Footscray came to play a more important role, and became the
location for later bridges. Michael Lynch established a punt and inn at
Footscray by 1840, and went about erecting a bridge in about 1866 (Max Lay),
despite being refused a permit to do so.
As the river was used by shipping (for the boiling down works at
Maribyrnong, and later the gunpowder magazine and meat works) Lynch’s
Bridge was constructed with a draw bridge span. It was rebuilt with a
horizontal lift span in 1882 to the design of G. Francis, which survived in a modified form into the twentieth
century, but was replaced with the new bridge on the Ballarat Road in 1936 This new Lynch’s Bridge was one
of the earliest composite steel and concrete bridges erected by the CRB.
A steel truss swing bridge was also constructed
down stream at Footscray in the 1920s, which lasted into the 1960s. This was a
unique bridge for Melbourne in having a lift span to allow passage of ships, an
in particular the gunpowder barges heading for the Saltwater River Magazine.
The Plenty River Bridge, erected in about 1861
to the design of G. Francis, is one of the earliest surviving Metal bridges in
Victoria, indicating the importance of this route and the productive farmland
it served, to the early colony.
The Barwon River formed an obstacle to travel
south and west of Geelong. A hotel and ford 3 miles west formed the village of
Fyansford, while south of Geelong Town a bridge was put over the Barwon in 1859
to a design of William Fairbairn & Sons of Manchester England. This wrought iron box girder bridge
with a 210 foot (64 metre) span which was the longest bridge span in Australia
and probably the most substantial engineering works of the time.
The Upper Portland road also came to prominence
as the way to the Fiery Creek goldfields and was surveyed by 1852. Shelford has
the possible claim to the first bridge in Victoria, erected in 1840 over the
Leigh (Yarrowee) River. A more substantial timber bridge was put up in 1851,
and this in turn was replaced by the Shire of Leigh in 1873-4 with a design by
Shire Engineer, C A C Wilson, and fabricated in situ from components cast by Ballarat
founder, John Price. This new bridge comprised two continuous hollow wrought
iron girders over three spans and supported on iron rollers attached to
bluestone piers and abutments (Alsop 1971).
Further along this route, the Woady Yalloak
Creek on the Rokewood Skipton Road had a timber bridge on stone abutments
erected by the Central Roads Board by 1856. By the 1880s the timbers had
deteriorated to the point the bridge was unsafe, and the Shires of Leigh and
Grenville funded repairs. The Leigh shire engineer CAC Wilson, prepared a design, for which he had to obtain Public Works
Department approval. The new McMillan’s Bridge incorporated locally made
trusses by Humble and Nicholson’s Vulcan Foundry in Geelong manufactured from
imported iron. The existing red
sandstone abutments of the 1856 bridge were modified to take the new trusses
(Chambers & Churchward 1999).
Figure
1: McMillans Bridge in about 1974
A little further west at Pitfield is another
similar sized lattice truss bridge on bluestone abutments, which may be earlier
than McMillan’s bridge.
Figure
2: Pitfield Bridge
Another important early wrought iron bridge
occurs on the Hamilton Highway route over the Woady Yallock Creek at Cressy.
Here, a two span lattice-girder bridge with buckle-plate deck on iron
cross-beams and bluestone abutments was constructed in 1880 again using trusses
fabricated by Humble and Nicholson. (Vines 1994).
Figure
3: Cressy Bridge
Together these bridges form a unique collection
of early lattice and girder bridges which demonstrate the importance of the
Western District route in nineteenth century Victoria.
The importance of routes to the coastal ports of
the western district at times eclipsed those to Melbourne. This can be seen in
a few surviving structures such as the Wollaston cable suspension bridge at
Warrnambool. Wollaston Bridge was erected
across the Merri River in 1890 to facilitate access to the Wollaston Estate of
noted district pastoralist and public figure, Sir Walter Manifold. The design
and construction of this bridge, which consists of a timber deck and
superstructure suspended from steel cables anchored across square tapered stone
towers to approach abutments, is attributed to Warrnambool contractor D.
Dobson. Manifold financed the bridge himself, and it is likely that
the choice of a suspension bridge also owes something to him, as the family was
quite ostentatious in its displays of wealth.
An early crossing of the Maribyrnong River for
traffic to the north west, west and south west was at Keilor. A ford 300 m upstream
or the old Calder Highway Bridge was initially used, and one of the names of
the site “Werribee Crossing” indicates its early role as a route to
Geelong – perhaps when the crossing at Avondale Heights was impassable
(Max Lay). The first temporary wooden bridge at Keilor was erected in 1848,
being the first bridge on the Maribyrnong but was washed away in a flood in
1852. Its replacement included large Howe truss timber spans to the design of
the Acting Colonial Engineer Samuel Brees. However this bridge was soon damaged in further floods and
replaced in 1854. It was subsequently repaired in 1857, 1860 and 1866, but
still remained close to collapse (Lay). A new bridge was built to the design of
George Brown, in 1868 possibly using
the abutments of the earlier bridge (O’Connor 1985:111). The Iron Bridge
at Keilor is one of the oldest existing metal girder road bridges in the state,
only the Hawthorn bridge and the bridges over the Melbourne-Bendigo and
Geelong-Ballarat Railways predate it.
Clunes and Creswick also lie between Ballarat
and Bendigo, and each gained substantial bridge in the late nineteenth century.
Jorgenson’s Bridge near Clunes dates from 1874, utilising continuous
wrought-iron lattice-girder deck trusses on stone abutments and one pier. The
1896 Creswick Creek bridge is later than most of the wrought iron
lattice-girder bridges, but like others, it also replaced an earlier laminated
timber arch.
The towns of Heathcote and Kyneton were linked
by a gold era road which had a dangerous ford on the Campaspe river near
Redesdale. The Shires of Metcalfe and McIvor managed to obtain Public Works
Department funding for a new bridge in 1869. This took advantage of the
misfortune of the ship carrying ironwork for the Hawthorn bridge which sank in
Hobson’s Bay in 1859. The ironwork was salvaged and 200 tons sold to the
shires by Langlands & Co for the bargain price of £1,000, T.B. Munz was the engineer supervising construction and the
contractor named Doran. The bridge was constructed on a steep and difficult site,
with sharply angled approaches and incorporating three wrought-iron
lattice-girders in a through-truss configuration on bluestone piers and
abutments. Curved wrought iron arches over the two lanes provide lateral
stability to the girders (Chambers 1996).
Figure
4: Mia Mia Bridge near Redesdale
Another important gold field route, was that
between the Ballarat- Maryborough and Avoca districts. The first Glenmona
bridge (a laminated timber design) was erected over Bet Bet Creek in 1857. This
route also served more distant travellers as an 1853 plan identifies it as the
Road from South Australia to Mt. Alexander (Chambers1999).
Roads heading inland from coastal ports
generally had an advantage in avoiding river crossings, at least at the lower
reaches of rivers. Therefore, substantial bridges could be avoided by route
selection. The Crawford River Bridge at Hotspur provided access between
Portland and the Western District town of Casterton. Erected in 1870 by local
contractor George Jarrett (possibly under direction of Shire engineer J. G.
Griffen) it comprises a riveted wrought-iron half-through
plate-girder design. It proved the Government inspecting engineer J. Crawley, correct in his judgement that the site required a more
expensive iron bridge when it withstood the massive flood in the year it was
built and so helped demonstrate the superiority of the type in flood prone
situations.
Further proposals for a bluestone bridge were
made as early as 1848, but it was not until 1851, that a public timber bridge
was erected near the end of Bridge Road becoming only the second bridge
crossing on the Yarra River. This was located just to the north of the present
alignment, possibly with the intention of allowing space for a more permanent
structure, which was duly completed ten years later as a more elaborate stone
structure joining Bridge Road to Burwood Road. These bridges opened up the
eastern suburbs of Melbourne to settlement, and speculative suburban
subdivision during the subsequent boom years (Cannon 1991:117-8). The Hawthorn
Bridge had a difficult start, with the first trusses imported from England,
sinking to the bottom of Port Phillip Bay. Replacement trusses were then
ordered, delaying the bridges construction. It was finally opened in 1861.
In the 1920s when a bitter dispute ensued over
funding for repairs or replacement following damage from floods, the Richmond
engineer closed the bridge as unsafe. It was reopened 3 days later, and a
temporary bridge built downstream the following year. The continuing arguments
and shortage of money during the depression led eventually to it being
strengthened using in-situ electric arc welding and the timber deck was
replaced with concrete. This was under the supervision of Public works
Department Chief Engineer G. Kermode (Churchward
2001; Rasmussen 1992).
Examples of bridges which represent this process
include the Glenmona or Bung Bong bridge, where the original laminated timber
arch had been washed away in the serious floods in Central Victoria in
September 1870. The earlier 1858 timber bridge designed by Clement Wilkes and built by
contractor A. Oughton, was of timber, and although expensive for the time lasted
only 12 years.
The replacement bridge was designed by Shire
engineer William
Woods and built by
Messrs Jenking and Lewis for £3,303
using lattice girders supplied by John Price of Ballarat and decking timber came from
Mount Cole.
Figure
5: Glenmona (Bung Bong Bridge
This can be seen as the prototype for a new
series of locally constructed wrought-iron lattice girder deck-truss main road
bridges with masonry substructures and timber decks, created specifically to
handle the sort of freak floods experienced across Victoria in the Winter and
Spring of 1870. The bridge incorporated relatively shallow lattice trusses and
a deck truss design to maximise the height above river level. This is believed
to be the first of this deck-truss type built as a consequence of the 1870s
floods and was probably a result of pressure from Public Works Department engineers
for better designed bridges that could cope with the occasional, but
devastating super-floods (Chambers 1997; 1999).
The Hotspur Bridge, while similar in many
respects to Glenmona, was constructed prior to the floods. However, the
Warrnambool-based inspecting engineer considered the site required more than
another light timber bridge and recommended the iron and stone bridge as a
precaution against further floods. When the 1867 Ellerslie timber, iron and
stone composite bridge had survived serious floods, it was used as a model for
a replacement bridge at Darlington (the ‘all-timber Elephant
Bridge’) over the Mt. Emu Creek (Chambers 1997).
The Castlemaine district had many of its timber
bridges washed away in the1870s floods, and then again in 1889. While some post
1870 bridges were adapted to the flood heights by provision of longer strutted
timber span designs, after the next floods, government subsidies encouraged
shires to build new bridges in composite stone-iron-timber designs. Zeal Bridge
near Pennyweight Flat in 1890, is a good example of this phase of bridge
building (Chambers 1997).
On some of the largest rivers, bridges used a
combination of timber trestle with timber beam spans over the flood plain, and
metal girders or trusses, or composite metal/timber trusses, over the river
channel where the longer spans were required. For example the Howlong bridge
employs Dare Truss incorporating a steel lower chord.
The failure of brittle steel under load and cold
conditions on the Kings Bridge, and the catastrophic failure of a span of the
West Gate Bridge during construction are classical modern equivalents, where
new materials and construction techniques were employed for the first time
here.
The opening up of Gippsland to settlement and
agriculture initially occurred via costal shipping and the Lakes. Sir John
Coode prepared designs for the New Entrance, as well as a canal to link the
rail head at Sale to the navigable Lake Wellington via the Thompson and La
Trobe Rivers. The road from Sale to Port Albert was the major route through the
district at the time, and so a bridge over the Thompson River at Longford had
to incorporate an opening span to accommodate the two transport needs. This was
designed by John Grainger and constructed
in 1881 by local contractor Peter Platt. It involved the erection of a central pier of cylindrical
cast iron caissons, on which the opening span rotated. The riveted wrought iron
half-through truss is flanked by plate girder spans on each side.
The Select Committee’s main
recommendations were for the establishment of a Central Roads Board and
District Roads Boards with the responsibility for determining lines of
communications, formation of Macadamised roads as the resources of the Government
permitted, and the on-going maintenance of roads. Three means of funding these
roads were proposed. The Central Roads Board would have direct Government
funding, the District Roads Boards would raise revenue through local government
and one-for-one government subsidy, and toll fees could be collected by
District Roads Boards to fund road maintenance.
The Central Roads Board would be responsible for
‘main roads’ in the colony, which were defined as being the roads
to Kilmore (Sydney Road) Bendigo-Echuca, Geelong-Colac, Bacchus Marsh-Portland,
Brighton Dandenong-Gippsland. All other roads would be the responsibility of
the district boards.
The District Roads Boards constructed roads and
bridges to quite varied standards, quality and design, particularly following
the demise of the Central Roads Boards in 1857. In some more prosperous and
heavily settled areas such as the Western District and the Central Goldfields,
quite high standards of construction were achieved. The Central board had the
function of approving design and expenditure for roads and bridges and was
particularly concerned that the standards of construction were maintained so as
to avoid wasteful false economies which had characterised much of the earlier
construction work.
The abolition of the Central Roads Board saw
some of its functions taken over by the Board of Land and Works, which had
responsibility for Public Works and Crown Lands & Survey and later the
Railway Department.
One of the roles of the new Commonwealth
Government was to provide for national communication. This was set under the
Federal Aid Roads Agreement of 1926. This agreement gave greater security of
funding for declared state highways, of which there were 1474 miles by 1927.
£360,000 per year were allocated from this source to Victoria The Act was
amended in 1931 to provide a user pays element through raising revenue via
customs and excise duties on motor spirit. However, in the 1930s and 40s
funding for roads remained static due to the impact of the depression and then
material and labour shortage during the Second World War.
When the Board was able to expend funds in its
first decade, it concentrated in on those rural roads, which provided greatest
cost-benefit. As a measure of its task, the CRB constructed 86 bridges in the period
1914-20, 46 in concrete and 41 in timber (Norm Butler 2002). In its annual
reports, the CRB emphasised the advantages of using permanent materials on
economic grounds, with a preference given to concrete. No mention was made of
metal bridges and no metal bridges were recorded as being constructed in the
period 1914-19 (Norm Butler 2002, CRB Annual Reports, 1914:65; 1917:7).
The central administration permitted a control
of standards through experimental work, testing and design specification. For
example The CRB pioneered the design and construction of electrically welded
steel structures with three particular examples standing out. CRB Annual
Reports in 1931 and 1932 describe that the Sunday Creek Bridge near Seymour as
the first welded steel truss bridge in the State. McKillop’s Bridge over
the Snowy River on the Bonang-Gelantipy Road was constructed in 1931 as an
electrically-welded continuous deck steel bridge claimed to be one of the
longest welded bridge in the world at the time. McKillop’s Bridge gained
notoriety when it was destroyed in a flood the day before its official opening in January 1934, when
floodwaters reached half-way up the trusses, pushing over one pier, dislodging
the trusses and washing them down stream. The bridge was subsequently rebuilt
(Butler 2002; CRB Annual Reports 1930-34).
The massive increase in motor traffic began in
the 1920s, slowed in the depression and war years, and then took off again
following the war. Road freight became the prominent road planning issue as railways
declined. Road bridge construction developed new design parameters in order to
accommodate the greater speed, volume and weight of this new traffic. Bridge
designers responded by making greater use of metal joists in timber bridges,
and eventual replacing most of the timber with new steel and concrete designs.
Another reason for
this move was the difficulty in obtaining satisfactory timber for the main
beams in timber bridges from the 1930s. to solve this, the Board adopted the
practice of using steel rolled steel joists instead of round timber stringers.
Many bridges were constructed in this manner with timber substructure, steel
stringers, timber crossbeams and a timber running deck. To maximise the length
obtainable with available RSJ sizes, the stringers were often welded or splice
bolted at quarter points to make a continuous
From the 1930s to 1950s the CRB built many
composite bridges employing concrete or
timber abutments and piers, RSJs for the main beams and timber decks. An
early example of the composite RSJ and timber deck bridge was the Hume Highway
Bridge constructed over Goulburn River at Seymour by the CRB in 1933 (CRB
Annual Report 1933). Cheynes
Bridge of 1947, built by the CRB on the Licola Road, was a late example of the
type which had become a typical form of country bridge in the 1930s. By the
post WWII period, pre cast concrete was a more common CRB bridge type and cast
in place flat concrete slab had also become popular (Butler 2002; Chambers
1996a).
Figure
6: Cheynes Bridge Licola
Norm Butler notes that the first composite
concrete and steel bridge deck in the State was built by the Country Roads
Board at Chinaman’s Creek at Broadford in 1934. This structure utilised
“rods bonding the steel joists and the concrete” (shear connectors)
to provide a design that was more economical in the use of steel. The work
embodied “a new idea recently developed by the Tasmanian Public Works
Department.” Due to the proportionally high costs of the fabrication of
the shear connectors, the Board at the time decided that overall it was not
economic to use this system. Twenty years later, however, when steel was in
short supply, this method became (and still is) the accepted system for steel
and concrete bridge deck construction” (Butler 2002).
The super elevated Ferguson’s Bridge built
by the CRB in 1939 over the Campaspe River, and which incorporated a banked,
curved deck designed to take the greater speeds of motorised traffic,
represents another aspect of the design trend for motor vehicles. However,
super-elevation in itself was practiced from very early days, being a carryover
from railways practice. An early example of super Elevation is the Wodonga
Creek Hume Highway Bridge of 1933 (Butler 2002; CRB Annual Report 1934:21).
spans and 290 feet long was constructed on
the Woolsthorpe Caramut Rd over the Merri River in 1949, the first such
structure built in Victoria
A significant large span composite concrete
and steel plate girder structure was constructed by the CRB on the Maroondah
Highway at Bonnie Doon in the early 1950s to provide for the raised water level
of the Eildon Weir (Lake Eildon)
The Spencer Street Bridge was constructed in
1928-30 following an Act of Parliament of 28 September 1927, but the Board of
Land and Works Railway Construction Branch, and opened on 12 February 1930.
Designed by CH Perrin and W D
Chapman, the bridge employed arched variable depth plate girders
and cast iron balustrades intended to match those on the existing
Prince’s and Queens Bridges.
The King Street Bridge, Kings Way and the
associated Flinders Street Overpass of 1961, was perhaps the first example of
major grade separation bridge in Victoria. However, it did not include the on
and off ramps, which came soon after with full freeway construction such as the
Maltby Bypass and South Eastern Freeway. King Street Bridge also gained
notoriety when only a year old, on a cold morning, a girder failed due to metal
fatigue and stress resulting in the partial collapse of a section of the
roadway. The subsequent Royal Commission found that the cause of the collapse
was inadequate contract co-ordination, supervision and deficient systems for
testing of the steel (Anderson 1994:190-98).
Other programs of
road widening and level crossing elimination were also well underway in the
1960s. Some of the earliest were the overpasses at Heathmont, Dandenong
Frankston Road, Barry Road Broadmeadows, Princes Highway Corio and Heidelberg
Road Clifton Hill, all commenced in 1958 (CRB Annual Report). The design
requirements for these bridges poised some unusual engineering problems. Grades
on approach embankments had to accommodate the generally underpowered vehicles
of the time. This was not always successful, as for example, “Mount
Mistake” on the Geelong
The 1961 rail overpass at Craigieburn on the
Hume Highway, was possibly the first dual carriageway controlled access road
and a precursor to the first freeway, the Maltby By-pass.
A significant change in bridge design
came as a result of the work of the research and experimental work of Melbourne
University Engineering Department. In particular Professor William Charles
Kernot was influential in his work on bridge
truss design and advocate of light, well-designed, scientific construction,
which gave cheaper and better results. He arrived in Australia in 1851 studied
at the University of Melbourne and worked in the Victorian Department of Mines
and Water Supply Office, before becoming Lecturer and then Australia’s
first Professor of Engineering 1868-1909. He was President of the Victorian
Institution of Engineers, The Victorian Institute of Surveyors and The Royal
Society of Victoria 1885-1900. He is commemorated by the Kernot Medal for
distinguished engineering achievement in Australia.
Figure
7: William
Charles Kernot.
Charles Anthony Corbett Wilson was an
important figure in the history of bridge building in Victoria. Wilson was born
in London in 1827 and articled in 1846 to a London engineering firm. He arrived
in Victoria in 1851, enticed to the gold diggings which proved unsuccessful. He
carried out the original survey for the Geelong to Melbourne Railway and was
employed in the construction of the original Iron Barwon Bridge at Geelong and
the Shelford Bridge. He later expressed a debt to the training he received
there under Charles Rowand. Wilson practised his profession for an incredible
sixty-four years (1846-1910) and was responsible for many iron, timber and
concrete bridges in western Victoria. He was succeeded by his son Charles
Corbett Powell
Wilson as shire
engineer on his retirement.
In the twentieth century, bridge engineering was
pushed forward on several fronts. In this regard John Monash was particularly
influential albeit as a reinforced concrete design engineer. However, he
certainly helped to have new ideas accepted in bridge design.
Due recognition should
also be given to the Country Roads Board in its influence on bridge design and
construction in the State. From a policy point of view, William Calder, the first Chairman, should be recognised for his view that
more permanent materials should be used for bridge construction, timber being
only used where other materials were well out of the question. Other significant CRB bridge
designers/constructors would include DV Darwin (Later Chairman
of CRB), and I J O’Donnell(also later Chairman of CRB). More research needs to be done
in this area to recognise the significant contribution made.
o
Political
themes – colonial control, district councils, central roads board,
district roads board – councils, PWD, CRB, MMBW.
o
Influence
of engineers – Wilson, Kernot, Coane, Perrin, Calder, Darwin
·
Bridge
building phases
o
Pioneering
– 40 all timber bridges - Lennox & others, some with stone abutments,
+ Princes Bridge
o
Gold
Rush – Stone &timber/stone, 100+ in 1850s, many stone bridges survive
(Axedale, Djerriwarrh, Avenel, Yendon)
o
Boom
– 1860s to 80s railway boom, engineering experimentations
=
Crimea
bridges and Box Girders (Church St. Barwon, Keilor)
=
Lattice
Girders (Hawthorn, Mia Mia,)
=
Open
Web truss (McMillans, Pitfield)
=
Rarities
(Cast Iron, W.I Arch)
o
CRB
standardisation (composites, RSJ)
Survey Method
·
Data
Acquisition
o
VicRoads,
Bridge Inspection System
o
National
Tryst Timber Bridges Study
o
Statutory
Lists – Victorian Heritage Register, Heritage Inventory, Register of the
National Estate, NRE Historic Places, National Trust, Heritage Overlays
o
Heritage
Studies and histories
o
Field
Survey
Recording and assessment
·
VicRoads
images (remote inspection)
·
Existing
studies
·
Field
inspection along 4 main routes
o
Upper
and Middle Portland Roads
o
Western
Goldfields
o
North
West
o
Gippsland
Analysis of results
·
3609
Bridges on database (most timber and metal)
·
2068
Metal road bridges
·
300
Identified of significance Local, Regional, State OR National
·
60
Structural / functional types / Groups,
·
25
Structural / functional classes (incomplete)
·
9
Metal road bridge classes
Analysis of data on metal bridges within the
database demonstrates that while a wide range of structural types are
represented in Victoria, the vast majority of metal road bridges are relatively
modern structures of standard span lengths and designs employing universal
beams or rolled steel joists. This is a factor of the exponential increase in
bridge replacement and construction in the second half of the twentieth
century. Geographic considerations such as the limited number of significant
and difficult crossings, and the dispersed nature of the road system are also
influential. Australian road bridge technology was also able to draw more
extensively on overseas precedents in the post World War II period, which meant
a lower level of experimentation and innovation was required.
Bridges were divided into 60 structural groups
according to their function, materials and design. These can be summarised
under 17 major classes. The distribution of bridges according to main
structural groups is shown in Error!
Reference source not found. and Error!
Reference source not found. below. The More Comprehensive listing of
Groups is included in Error!
Reference source not found. in the Appendices of this report.
It should be noted that in Error!
Reference source not found. shows numbers of bridges in each class
on a logarithmic scale, in order to present the data for widely variable
classes. Most of the all-timber bridges on the National Trust Bridges Database
have been excluded from this listing, although those classes for timber bridges
are included where metal components form significant structural elements. The
listing for timber bridges includes a total of 793 timber beam road bridges of
which 63 incorporate some metal components, either steel deck, cross-beams or
relieving beams.
