Kooloonbung Creek Footbridge Options Study ... - Hastings Council

Kooloonbung Creek Footbridge
Options Study Report
Ref: T-N0115.00/2REP
Proposal Prepared for Port Macquarie-Hastings
Council – August 2012

Kooloonbung Creek Footbridge
Options Study Report
August 2012
Prepared for Port Macquarie – Hastings Council
Opus International Consultants (NSW) Pty Ltd
Newcastle Office
Suite 2, 8-14 Telford Street, Newcastle NSW 2300
PO Box 734, Newcastle NSW 2300
Australia
Prepared By
Reviewed By
Telephone: +61 2 4907 7600
Jason Parrott Facsimile: +61 2 4926 1190
Senior Bridge Engineer
Date: 15 th August 2012
Reference: T-N0115.00/2REP
Status: Draft
Devin Wardill
Senior Bridge Engineer
Approved By
Hugh Tait
Business Manager Newcastle
© Opus International Consultants (NSW) Pty Ltd 2012

Options Study Report
Kooloonbung Creek Footbridge
Port Macquarie – Hastings Council
Contents
1. EXECUTIVE SUMMARY ..................................................................................................................................... 2
2. INTRODUCTION ............................................................................................................................................... 3
3. SITE INFORMATION.......................................................................................................................................... 5
4. DESIGN CRITERIA ............................................................................................................................................. 7
5. SPAN ARRANGEMENTS AND MATERIALS ......................................................................................................... 8
6. FOOTBRIDGE OPTIONS................................................................................................................................... 11
7. SIGNIFICANT CONSTRUCTION HEALTH AND SAFETY & RISK ISSUES ............................................................... 16
8. SIGNIFICANT ENVIRONMENTAL RISK ISSUES .................................................................................................. 17
9. CONCLUSION AND RECOMMENDATIONS....................................................................................................... 18
10. REFERENCES ................................................................................................................................................... 20
APPENDIX A – CONCEPTUAL ILLUSTRATIONS ............................................................................................................ A1
T-N0115.00 1
August 2012

Options Study Report
Kooloonbung Creek Footbridge
Port Macquarie – Hastings Council
1. EXECUTIVE SUMMARY
The Port Macquarie- Hastings Council continuously strives to improve its infrastructure and in doing so it has engaged
Opus International Consultants to investigate the options for the proposed footbridge over Kooloongbung Creek in
Port Macquarie Town Centre.
It is proposed to improve the pedestrian crossing which currently consists of a narrow footpath on either side of the
Buller Street Bridge, thus providing betterment of economical service and operational safety.
Four footbridge options have been evaluated and discussed in this report and are listed below along with their
estimated constructions costs (costs for relocation of utility services have not been included).
Option 1 – Single Span Steel Truss Footbridge $510,000
Option 2 – Single Span Timber Truss Footbridge- $550,000
Option 3 – Cable Stay Footbridge $545,000
Option 4 – Multi Span Prefabricated Deck System $445,000
Opus recommends, following Council approval, to progress the preferred Cable Stay Option into the preliminary
design phase. We believe that this Cable Stay option best meets with the Council’s footbridge objectives. There is
considerable benefit with the aesthetics of this form of footbridge as it will provide an eye catching structure, which
will harmonise with the rest of the proposed masterplan developments in Port Macquarie. The cable stay mast will
also be in keeping with the nautical theme in the port environment.
T-N0115.00 2
August 2012

Options Study Report
Kooloonbung Creek Footbridge
Port Macquarie – Hastings Council
2. INTRODUCTION
Opus was invited by Port Macquarie-Hastings Council to provide a detailed options study to consider the feasibility of
various footbridge concept designs for the crossing at Kooloonbung Creek in Port Macquarie.
Port Macquarie-Hastings Council is looking to provide a footbridge that will both be aesthetically pleasing and fit into
the overall vision of the town’s masterplan. The bridge concept therefore seeks to be visually pleasing, whilst
providing a practical link between the east and west shores of Kooloonbung Creek. The masterplan proposals will
increase tourism visitations and encourage an active use of the area around the proposed site (see below), in which
the footbridge would be a key landmark.
Figure 1 : Location Plan
This report investigates and evaluates a variety of solutions based on technical, financial constructability and
environmental factors and concludes with recommendations, which are considered the optimum given the constraints
and conditions of the bridge site. The merits of, and considerations into, the feasibility of each option have been
discussed in this report and are presented in section 5.
At this stage of the project, for the purpose of evaluating concept designs, the assumption has been made that the
footbridge would be located to the north and parallel to Buller Street Bridge, shown in figure 1. Should further
progress with the Port Macquarie Foreshore Masterplan identify that the location should change; the concept designs
recommended in this report would be subject to further evaluation at an additional cost to the Council. The additional
costs expected will generally increase by a similar factor to the percentage increase in required span, which take into
account the design complexity, increased foundation requirements, quantity of materials and construction time.
T-N0115.00 3
August 2012

Options Study Report
Kooloonbung Creek Footbridge
Port Macquarie – Hastings Council
The report also concentrates on the following criteria to assist with evaluating the most appropriate options:
• Understanding and appreciating the requirements desired by Port Macquarie – Hastings Council so that
Opus formulates an option that best fits Council’s objectives as well as value for money.
• Formulating the option that is most suitable to the site and its existing conditions and constraints.
• Provide bridge engineering recommendations on the preferred concept design option and advise
whether this option meets engineering good practice and current Australian standards.
• Provide information/issues of significance that may need to be addressed further following on from the
concept.
• Advise Port Macquarie-Hastings Council of any further information that needs to be obtained
at/following the concept design stage.
Opus has reviewed the concept design options with in accordance with the criteria listed above, along with
information obtained during the site visit and has prepared this report for Councils Consideration.
T-N0115.00 4
August 2012

Options Study Report
Kooloonbung Creek Footbridge
Port Macquarie – Hastings Council
3. SITE INFORMATION
The proposed bridge will be located to the north of Buller Street Bridge on William Street in Port Macquarie, NSW
(shown in photo PO1 below). The footbridge will cross Koolongbung Creek to provide both pedestrians and cyclists
safe passage for their recreational movements within the town centre.
Photograph P01 – View on North side of Buller St. Bridge
The structure is located in an urban area which is enjoyed by many of the local community, and carries a very popular
footpath, which does not currently provide adequate width for pedestrians in accordance with Australian Standards.
The topography of the surrounding land is fairly flat, with significant recreational and commercial features in the area
which include and are not restricted to:
• The commercial marinas, located to the north of the proposed site (see figure 2 overleaf), which provide
a visually interesting and colourful foreshore environment, and which can be accessed from the
proposed bridge via a footpath leading to a curved timber boardwalk;
• The historically significant pilots boat shed, located at the western end of Clarence Street, again accessed
from the proposed bridge via a footpath on the east embankment of the creek; and
• The four storey Mid-Pacific Motel which has a strong visual presence along the foreshore.
T-N0115.00 5
August 2012

Options Study Report
Kooloonbung Creek Footbridge
Port Macquarie – Hastings Council
Figure 2 : Extract from Port Macquarie Foreshore Masterplan
Utility Services
The site inspection identified that an overhead power utility is present near to the proposed location of the
footbridge, which consists of an 11KV line. Liaison with Essential Energy is underway to determine the scope to
incorporate their service into a conduit within the footbridge, or on Buller Street Bridge.
Dial before you dig enquiries have been made which identified the following:
• Essential Energy – Assets have been identified within the extent of the proposed works. Please see
Appendix B for details.
• Optus – No Assets affected;
• Telstra – No Assets affected; and
• Nextgen Networks - No Assets affected.
Geotechnical Information
The geotechnical investigation will be carried out upon confirmation of the preferred concept design. Should the
ground conditions be found to be inadequate, the concept designs may be subject to change.
T-N0115.00 6
August 2012

Options Study Report
Kooloonbung Creek Footbridge
Port Macquarie – Hastings Council
4. DESIGN CRITERIA
For the purpose of evaluating concept designs, the assumption has been made that the footbridge would be located
to the north and parallel to Buller Street Bridge, shown in figure 1 in section 1 of this report. The cumulative span
requirement in this position would be a total of approximately 40m. Should further progress with the Port Macquarie
Foreshore Masterplan identify that the location should change; the concept designs recommended in this report
would be subject to further evaluation.
The footbridge and related works shall be designed in accordance with Port Macquarie-Hastings Council Aus Spec in
addition to Australian Bridge Design Standard AS5100 and AUSTROADS.
The applied loadings to be considered in the analysis for the design is as follows
• Footway, walkway or footbridge live loading
-5KN/m2
• Special loading
-Dynamic Loading (For Cable Stay Options).
-Wind Loading.
-Impact Loading.
The proposed bridge soffit level would be no lower than that of the existing road bridge adjacent. This level has been
assumed to be clear of previously recorded flood events.
T-N0115.00 7
August 2012

Options Study Report
Kooloonbung Creek Footbridge
Port Macquarie – Hastings Council
5. SPAN ARRANGEMENTS AND MATERIALS
With consideration of both the proposed location of the bridge and the total span distance required, several span
arrangements can be considered:
• Single span simply supported deck structure;
• Single span suspended structure (cable stay or suspension bridge);
• Multi-span simply supported deck structures.
Single span simply supported deck structures
Several design concepts are available which can span over 40m within feasible constraints. These include suspended
structures, arches and trusses. The truss typically consists a triangulated framework of elements that act primarily in
tension and compression and can be constructed from timber or steel. It is a light-weight yet very stiff form of
construction. Trusses may be used as girders below the deck level, or as through girders with the deck at the bottom
chord level. Such through truss girders minimise the effective construction depth, and the length of approach
embankments. Hence, they are particularly suited to footbridges. The image below shows a Warren truss bridge,
fabricated and supplied by Outdoor Structures, based in Queensland.
They are considered expensive
to fabricate today, being labour
intensive and also leave several
maintenance issues which have
to be carefully addressed (for
example, ease of access).
However, they can still show
advantages in particular
applications such as
footbridges.
Single span suspended structures
Where support piers are not feasible or cost effective, the span of beams and/or truss type footbridges may be
extended by the assistance of cables. This involves building towers at one or both ends of the bridge that are tall
enough to achieve effective angles for the support cables. The more conventional type of suspension bridge uses
continuous cables supported by towers at each end of the bridge which hang in a catenary to support vertical hanging
cables from which the bridge deck is suspended. In modern day engineering the use of cable stay structures has been
more widely used due to the relative ease in the construction phase, over that of the suspension bridge, although the
concept for both remain the same. A schematic outline of these type of bridges is shown in Figure 3, below.
T-N0115.00 8
August 2012

Options Study Report
Kooloonbung Creek Footbridge
Port Macquarie – Hastings Council
Figure 3 - Schematic of Cable Stayed and Suspension (PBWorks,2008)
The bridge deck may be flexible or rigid but must be strong enough to support the live loads between the support
cables and also to resist wind, dynamic and hydraulic loading.
The main applications of cable type footbridges, suspension and suspended, are for spans over 20 to 25m where
intermediate pier supports are impractical. They are a cost-effective solution for footbridges carrying pedestrians and
cyclists, for medium to long spans.
Multi-span simply supported deck structures
Multi-beam steel, timber or composite
decks are very competitive for bridges
in the short span range. They comprise
a deck slab or cross members which are
supported on top of several girders. The
image to the left shows a timber
footbridge, fabricated and supplied by
WRD, Oregon USA.
For simple spans up to 25m, rolled universal steel beams are economic and are available in a range of sizes ‘off the
shelf’. Very little fabrication is required, usually only the fitting of stiffeners for bearings and the attachment of
bracing. Sections may also be bent to provide precamber and/or horizontal curvature.
For longer span bridges, deeper girders can be fabricated from plates or more spans can be constructed. This however
often means that intermediate piers are required in unfavourable locations. This gives scope to vary the web and
flange sizes and the steel grades for an efficient design. Variable depth girders are often used to give greater
economy, and also to enhance aesthetics. Such plate girders can be readily fabricated with curvature in plan and
elevation.
T-N0115.00 9
August 2012

Options Study Report
Kooloonbung Creek Footbridge
Port Macquarie – Hastings Council
Materials
For the same weight there is not a great deal of difference in the strength of steel and hardwoods. However, for the
same section size, steel is stronger and therefore designs are generally more compact using this material. Steel is
therefore particularly suited to construction of truss type bridges where joining of the members is also easier than for
timber.
Provided steel is adequately protected against corrosion, it will have a considerably longer life than that of timber.
Protection by simple hand methods of brushing or spraying is likely to be more effective than for timber and
maintenance necessity would be less frequent.
The only disadvantage of using steel over timber is that more complex tools and equipment are required in the
construction. In most cases construction will need to be in a workshop and components or sections would then be
transported to site for assembly.
Several types of Fibre Reinforced Polymers are available on the market today and are being used more and more
frequently where previously timber was the material of choice. FRP’s have an advantage over timber as they provide a
durable and long lasting alternative which is not significantly more expensive when a whole life cost is evaluated.
Companies such as Wagners CFT can offer glass fibre composite sections which weigh around 1/3 of an equivalent
timber girder. The glass fibre composites are not susceptible to durability issues which timber, as well as steel, suffer
from (for example termite attack, borers, decay, corrosion etc.). Wagners CFT girders have also been fatigue tested to
1.2 million cycles and exhibit no loss in strength or stiffness. Typically more expensive than steel, glass fibre
composites can often work out an economic alternative when the whole life costing is considered.
T-N0115.00 10
August 2012

Options Study Report
Kooloonbung Creek Footbridge
Port Macquarie – Hastings Council
6. FOOTBRIDGE OPTIONS
Concept Options
Following a review of the market, identifying the availability and cost of prefabricated footbridge concepts, Opus have
short listed 4 concept designs to review and discuss the merits. These concepts incorporate the Council’s
requirements, which were outlined in the Engineering Design Scope of Works, May 2012 (Ref BC-1201-001).
The concepts have been summarised in this section of the report and are shown conceptually in Appendix A of this
report.
Option 1 – Single Span Steel Truss Footbridge
Option 1 proposes to span Kooloonbung Creek onto concrete abutments using a steel truss. These types of footbridge
are available in prefabricated form from several companies in Australia as well as bespoke design options.
The photograph to the right, is a
prefabricated steel truss footbridge
designed and supplied by Outdoor
Structures, Queensland.
The photograph to the left, is a bespoke steel footbridge
designed by Opus and constructed in Wattle Street,
Sydney.
As can be seen in the photograph (shown above), a covered footway can easily be incorporated in the truss footbridge
concept, which provides addition protection to both the users of the creek crossing and components of the bridge
which would otherwise be exposed and could corrode.
This option provides a relatively simple solution, but is considered to have poor aesthetic properties when compared
with other options, although a balustrade design (one example shown on page 15 of this report) could transform the
visual impact. The concept of a single span option would be particularly beneficial in the construction phase as
foundations would not be required in the creek.
Estimated Construction Cost (Based on supply quotation from Outdoor Structures): $510,000
T-N0115.00 11
August 2012

Options Study Report
Kooloonbung Creek Footbridge
Port Macquarie – Hastings Council
Option 2 – Single Span Timber Truss Footbridge
Option 2 proposes to span Kooloonbung Creek onto concrete abutments using a timber truss. These types of
footbridge are also available in prefabricated form and have the benefit that on site assembly would involve less
complex tools and equipment.
The photograph on the right of a
single span timber through truss
footbridge, is courtesy of Wood
Research and Development and
Outdoor Structures, Queensland.
The photograph to the left, courtesy of
Wheeler, shows a single span timber
truss footbridge similar to, but on a
smaller scale to the bridge pictured
above.
Different types of deck material can be utilised easily and therefore provide a more durable and low maintenance
option.
As with option 1 the concept of a single span option would be particularly beneficial in the construction phase as
foundations would not be required in the creek. This option is considered to have more favourable aesthetics
compared to option 2.
Estimated Construction Cost (Based on supply quotation from WRD and Outdoor Structures): $550,000
T-N0115.00 12
August 2012

Options Study Report
Kooloonbung Creek Footbridge
Port Macquarie – Hastings Council
Option 3 – Cable Stay Footbridge
This option proposes a single pylon on the west bank of Kooloonbung Creek, which supports the bridge deck by way of
cables, see below. These structures benefit from utilising a slender deck system, which is typically pleasing to the eye.
The photograph to the left, is courtesy of Outdoor
Structures and shows a prefabricated cable stay
arrangement for a long span footbridge.
The image to the right shows a typical arrangement for
a single pylon cable stay bridge. (Stockton on Tees
(Britton, 2001)
There are various configurations available with the number of masts, the layout of the cables, the type of mast and
the span proportions. The favoured cable stay configuration is shown is illustrated in the photo above and in Appendix
A of this report. We believe due to the relatively short span for a cable stay bridge the single span pylon would be the
most suitable option and the topography of the approach banks would best suit the location of the back span to be at
the west approach.
The deck construction can be designed using one of several different materials or a combination of, in order to
achieve an aesthetic, and durable structure.
As with option 1 the concept of a single span option would be particularly beneficial in the construction phase as
foundations would not be required in the creek. The cable stay option also has the most appropriate and pleasing
aesthetics in this high profile Creek location.
Estimated Construction Cost (Based on supply quotation from Outdoor Structures): $545,000
T-N0115.00 13
August 2012

Options Study Report
Kooloonbung Creek Footbridge
Port Macquarie – Hastings Council
Option 4 – Multi Span Prefabricated Deck System
Option 4 comprises a 3 span timber deck structure with two intermediate piers near to the creek shore lines. This
concept benefits from having a slender deck system as oppose to some of the single span options as the length of
each span is reduced.
The photograph to the left, courtesy of Wagners
CFT Manufacturing Pty Ltd, shows glass fibre
composite pedestrian bridge structure. The
structural components and the balustrade sections
are all formed from glass fibre composite.
The photograph to the right,
courtesy of Outdoor Structures
shows timber deck arrangement
over several short spans.
The photograph on the left, courtesy of Unibridge,
shows a prefabricated modular footbridge
As with each of the options, various types of deck material can be utilised easily and therefore provide a more
durable and low maintenance option if required.
Timber, glass fibre composite and steel could all be utilised easily in this concept, which could have durability
and subsequently longevity benefits.
Estimated Construction Cost (Based on Supply quotation from Wagners CFT): $445,000
T-N0115.00 14
August 2012

Options Study Report
Kooloonbung Creek Footbridge
Port Macquarie – Hastings Council
A decorative ballastrade can be incorporated into each of the 4 options outlined in this report. One example of a
balustrade design is shown below (Extract from Scully’s Drawing No: GA-03):
A comparative summary of the concept options to provide a footbridge over Kooloonbung Creek has been discussed
in section 9 of this report. The evaluation has been carried out on the following basis:
• Construction cost.
• Whole life cost.
• Ease of construction.
• Future inspection and maintenance requirements.
• Health and Safety issues.
• Environmental issues.
• Construction programme duration.
• Disruption to the local community.
The Preliminary cost estimates for proposed options have been built upon on quotations to supply and deliver
prefabricated footbridges. Construction costs have been estimated based on past schemes and are for information at
this stage of the project.
T-N0115.00 15
August 2012

Options Study Report
Kooloonbung Creek Footbridge
Port Macquarie – Hastings Council
7. SIGNIFICANT CONSTRUCTION HEALTH AND SAFETY & RISK ISSUES
Health and Safety procedures and processes are to be followed to ensure OH&S considerations are incorporated in all
aspects of execution of the project services. Port Macquarie- Hastings Council Policies, Procedures, inductions and
special licences required to access and operate within the site will be adhered to. Opus believes that the safety and
well-being of staff and other parties affected by our work is of primary importance.
In order to provide a formal means of identifying the risks inherent in this project and to communicate them to other
members of the design team and the contractor, a designer’s risk assessment shall carried out at the early stage of the
design process. This will be carried out at an early stage of the design to address and help to eliminate the hazards
associated with construction health and safety. This assessment would recommend mitigation measures to reduce
risks from those hazards that cannot be eliminated.
Prior to this designers risk assessment and the verification of the preferred concept design, the likely risks that are
associated with this project will include:
• Injuries to personnel;
• Contaminating land and watercourse;
• Injury through contact with / inhalation of hazardous materials during construction and maintenance;
• Contact with skin causing irritation and vibration;
• Injury through handling heavy materials;
• Falling into water and drowning; and
• Damage to neighbouring road bridge.
Health and Safety issues are of paramount importance. All stages of construction and beyond should be considered
during a full risk evaluation, and include identification of significant hazards which affect the workforce, public and
future inspection, maintenance and demolition operations. Preliminary health and safety risk assessments have been
undertaken and significant factors are noted below:
• Longer construction periods present greater exposure to environmental risks, such as flooding.
• Routes for emergency services shall be maintained, or diverted on agreed alternatives.
• Manual handling operations should be minimised.
T-N0115.00 16
August 2012

Options Study Report
Kooloonbung Creek Footbridge
Port Macquarie – Hastings Council
8. SIGNIFICANT ENVIRONMENTAL RISK ISSUES
Environmental issues are of equal importance to safety matters. All stages of construction and beyond should be
considered during a full risk evaluation, and include identification of significant impacts which arise during the design,
construction, and maintenance operations. Preliminary environmental risk assessments have been undertaken and
significant factors are noted below:
• The finished appearance of the work proposed should be in keeping with the surroundings.
• Noise and dust emissions are likely to be significant and therefore working hour restrictions should be
included in specification for the works.
• Opportunities should be maximised during scheme design for recycling and use of reclaimed materials.
• Statutory undertakers apparatus should be located and protected/diverted to avoid pollution events.
• The scheme should seek to minimise vehicle movements, but this should be balanced against potential
re-use of arisings on other Council schemes if appropriate.
• Welfare facilities should be self-contained within the site extent.
• Impact to local ecology should be minimised. Specialist advice should be sought for effects to any local
designated sites and treatment of significant effects to biodiversity. Schemes with nominal land-take will
have less effect on the local ecology.
• The work is likely to involve earthworks and therefore the design shall strive to include retention of
existing vegetation where practicable.
The level of environmental impact resulting from the proposed works is expected to be low, as the likely and potential
impacts would be localised, of short-duration and would result in minimal disturbance to the watercourse. It is
expected that the causeway will have a marginally higher impact to the watercourse due to its extensive amount of
concrete onto the river bed.
It is our understanding that an environmental study would be carried out prior to commencement of the works.
T-N0115.00 17
August 2012

Options Study Report
Kooloonbung Creek Footbridge
Port Macquarie – Hastings Council
9. CONCLUSION AND RECOMMENDATIONS
Following the summary of the options in section 6 of this report, Opus recommends to progress into the preliminary
design phase with the Cable Stay Option, Option 3. The merits and constraints for each concept, considered in this
report are discussed below. Illustrations of these options are shown in Appendix A.
Option 1 – Single Span Steel Truss Footbridge
The truss concept is simplistic and fit for purpose has merits in the relatively short site construction time, the proven
efficiencies in design and the need for only two abutments. However there are many complications and constraints
which include fabrication complexity, more complex tools and equipment than that of a timber truss, cost and
prefabrication time.
The structure has the benefit of being durable and reasonably maintainable, over the timber truss option for example,
although it will require painting. The design life of the structure will be significantly longer than that of a timber
counterpart.
The potential requirements to divert or isolate the adjacent power line in both the design and construction phase
would be less adverse than that of the Cable stay footbridge.
With the council’s requirements for aesthetics are considered independently, this option is not considered to fulfil the
requirements, as in comparison to a cable stay bridge for example, the footbridge would not be a landmark feature.
Option 2 – Single Span Timber Truss Footbridge
The timber truss concept is a simplistic traditional structural form that due to its arched configuration can span the full
40m and additionally provide an aesthetically pleasing structure. This form of structure has a similar structural
appearance to a bridge that has been used elsewhere in the town..
Due to this footbridge consisting of predominantly timber elements it has long term cost implications due to greater
maintenance requirements during its life span. The design life of the structure will also be less than the other options
considered.
The potential requirements to divert or isolate the adjacent power line in both the design and construction phase
would be less adverse than that of the Cable stay footbridge.
This option fulfils the Council’s requirements of an aesthetic pleasing structure. Although, there is long term cost
implications due to greater maintenance requirements.
Option 3 – Cable Stay Footbridge
The cable stays greatest merit is that it is aesthetically pleasing. In addition the more slender deck component requires
less quantity of materials to construct it, as the structural integrity is assisted by the cables.
Again the structure has the benefit of being durable and reasonably maintainable, over the timber truss option for
example, although it will require painting. The design life of the structure will be significantly longer than that of a
timber counterpart when either steel or FRP is used for the deck components.
Some complexity in the construction phase in turn means that construction time would be longer than some of the
other options; however innovation in the methodology could subsequently reduce this.
T-N0115.00 18
August 2012

Options Study Report
Kooloonbung Creek Footbridge
Port Macquarie – Hastings Council
The overhead power lines located at the site are a concern when proposing a large pylon in close vicinity. Further
liaison with Essential Energy is required, as with all of the other options, however it is more likely the service would
need to be diverted should this option progress.
This option fulfils the Council’s requirements of an eye catching and aesthetic structure.
Option 4 – Multi Span Prefabricated Deck System
The multi span prefabrication concept will allow the use of standardised off the shelf elements that will provide
benefits in both cost and shorter construction periods. However, pier supports will be required in the creek that will
significantly increase the construction complexity and will limit the time and cost saving gained form the
superstructure.
These additional piers within the creek also have the disadvantage of creating additional obstructions to water traffic
and risk from impacts from flood debris.
The potential requirements to divert or isolate the adjacent power line in both the design and construction phase
would be less adverse than that of the Cable stay footbridge.
With the council’s requirements for aesthetics are considered independently, this option is not considered to fulfil the
requirements, as in comparison to a cable stay bridge for example, the footbridge would not be a landmark feature.
Recommendations
The other more conventional Options 1 and 4 are dismissed on the grounds that the Council prefers an aesthetic
footbridge that is required to be an eye catching structure, which is to harmonise with the rest of the proposed
revitalisation of the town. Although Option 2 also is considered to possess pleasing aesthetics it lacks an elevated focal
point that is provided from a cable stay mask, which will harmonises with the nautical environment of the port. Option
2 also necessity greater maintenance requirements during its life span.
The cable stay footbridge has also been chosen over other forms of aesthetic complex bridges, such as suspension
footbridges, because it has the advantage of reduced construction costs due to reduction in number of elements such
as fewer towers, cables and anchor points required.
T-N0115.00 19
August 2012

Options Study Report
Kooloonbung Creek Footbridge
Port Macquarie – Hastings Council
10. REFERENCES
Britton, (2001). The Teesquay Millennium Footbridge, Stockton on Tees. Retrieved August 11, 2012 from
http://www.freefoto.com/preview/11-43-19/The-Teesquay-Millennium-Footbridge--Stockton-on-Tees
PB Works, (2008).BRIDGES. Retrieved August 10, 2012 from the structures art web site: http://structuresart.pbworks.com/w/page/11233762/Bridges
T-N0115.00 20
August 2012

Options Study Report
Kooloonbung Creek Footbridge
Port Macquarie – Hastings Council
APPENDIX A – CONCEPTUAL ILLUSTRATIONS
T-N0115.00
August 2012
A1