Innovations were developed to deliver significant benefits in program savings, value for money and community amenity through enhanced urban design.
The Regional Rail Link (RRL) project, the Australian state of Victoria’s first new rail line in 80 years, was jointly funded by the state and the Commonwealth of Australia. It is the largest rail investment in Victoria’s history and a critical component of the Australian government’s major transport investment to ‘future ready’ the city for expected exponential growth in the western suburbs of Melbourne.
The new line will cater for an extra 54,000 passengers a day and will cut commuting time from Melbourne's booming western suburbs and the fast growing regional centres of Geelong, Ballarat, and Bendigo. The new link separates regional trains from metropolitan trains for the first time, giving the trains of these regional cities their own dedicated track.
The RRL project was divided into six work packages, delivering a mix of alliance, design, and construct contracts. WSP | Parsons Brinckerhoff worked in an alliance with the Regional Rail Link Authority (RRLA), two train operators (MTM – the metropolitan rail operator, and V/Line – the regional rail operator), Thiess Contractors, Balfour Beatty, and Jacobs to deliver the $835 million rail upgrade from Footscray to Deer Park (FDP) in Melbourne’s west.
This article provides an overview of some of the challenges in delivering a project in a live railway environment (see Figure 1). The work involved the design and construction of:
- 7.5 kilometres (km) of new track;
- 10km of new overhead wiring;
- 10 new rail bridges;
- removal of two level crossings by construction of two road/rail grade separations;
- over 3.5km of retaining walls;
- a new sub-station;
- signalling upgrades;
- a new station at West Footscray; and
- upgrades at Footscray and Sunshine stations (see Figure 2).
Work commenced in 2012 and was completed by mid-2014. Efficiency savings, driving down costs, and achieving great outcomes was the alliance partners’ goal at every stage of the project. Some of the strategies used are described below.
COMPETITIVE TOC PROCUREMENT PROCESS – Delivering Innovation and Value for Money
Alliance contracts have been used in Australia since the mid-nineties to deliver outstanding results on construction projects. The use of a competitive target outturn cost (TOC) delivery approach helped to optimise the project solution and achieve an optimised project cost.
During the competitive TOC process, the alliance team took the previously prepared reference design and developed a design and construction solution. Options and innovations were developed helping to underpin the team’s philosophy of segregation by separation (i.e., separating the work sites from the hazards of the operational railway) and minimising disruption to the transport network.
Through this process, a number of solutions were developed that delivered significant benefits in terms of: program savings resulting in a six month program reduction on a baseline 36 month program; value for money by reducing overall costs by approximately 15 percent; and improved community amenity through enhanced urban design outcomes. Key innovations were developed during the competitive TOC process.
Nicholson Street Bridge Alternative Structural Form
One of the major structures on the project is the Nicholson Street Bridge. It carries one of the main thoroughfares, Nicholson Street, through the heart of the busy suburb of Footscray over the metropolitan and Australian Rail Track Corporation (ARTC) railway lines.
The original reference design solution comprised a two span concrete slab/plank structure sitting on new piled abutments. Our design solution incorporated a single span arched steel truss bridge and retained the existing northern abutment. The solution provided an architectural ‘feature’ bridge, supporting local development plans and the regeneration of the area (see Figure 3).
Optimised Location for West Footscray Station
The old station at West Footscray comprised two side face platforms serving the MTM metropolitan
network lines. In order to accommodate the additional V/Line regional lines within the narrow
congested corridor it was necessary to rebuild the existing station.
During the competitive TOC phase, a solution was developed comprising a new island platform station to the west of the old station. The existing metropolitan tracks were maintained during the works. The island platform was constructed to the southern side of the existing metropolitan tracks. The station was built immediately south of the existing metropolitan lines and the tracks realigned around the station during a track closure (occupation).
When the station was complete the additional V/Line regional tracks were located on the southern side of the new station. This solution resulted in considerable cost and time savings; eliminated disruption to the ARTC freight network; and minimised disruption to other networks. The new station was able to be built in a greenfield environment which was safer and more efficient (see Figure 4).
MAXIMISATION OF PREFABRICATION
Delivering railway infrastructure in a congested brownfield environment presents unique challenges. Construction windows for works within the live railway ‘danger zone,’ above the track or below the track, are significantly constrained by opportunities to close the railway to passenger and freight traffic.
To deliver the project within the agreed program, whilst constructing within reduced construction windows, required solutions that maximised off-site construction; minimised wet trades; and delivered high quality outcomes. Prefabrication of structures and major structural elements was one of the techniques utilised by the project to achieve these goals.
The main benefits of prefabrication realised by the project included a reduction in site build times; improved quality and safety; and reduced wastage. Design packages were developed from the outset to maximise prefabrication and repetition of structural elements (i.e., reduced special/unique details), and to support limited construction windows (see Figure 5).
Examples of prefabrication and their associated project benefits are included below.
Within stations there are a number of areas where prefabrication can be used including:
- station platforms;
- station overpass superstructures and piers, and associated ramps and stairs; and
- station canopies.
The benefits of prefabrication are best demonstrated at West Footscray Station, where a new station was built adjacent to the existing track alignment. Completion of the in-ground works, realignment of the tracks, and commissioning of the new station was completed in approximately three months.
The project includes three footbridge structures over the rail corridor; the longest (HV McKay footbridge) has a 66 metre clear span. The superstructure for each of these footbridges was fully prefabricated, including parapet screens, and lifted into position during short occupation windows.
For most road and rail bridges on the corridor, the size of the bridge precluded prefabrication (both for transportation and lifting) and adjacent urban development precluded off-line construction. Connection details were designed to support rapid construction and limit exposing staff to working at height (see Figure 6).
At the St Albans flyover, commencement of demolition of the existing 1920s steel and concrete deck to placing the final beam of the 72 metre long bridge and handing over to the track team took approximately 72 hours. Such a short time scale was largely dependent upon prefabrication and repetition in construction activities.
At the second of the two grade separations on Anderson Road (on the Sydenham/Bendigo lines in Sunshine), there was sufficient space adjacent to the bridge site to enable the bridge to be constructed off-line and slid into position. Commencement of the bridge slide to completion of track laying took approximately 30 hours.
REDUCING WHOLE OF LIFE COSTING
It was one of the project objectives to reduce whole of life costs (WoLC) so that new infrastructure would be more cost effective to operate and maintain. The project measured WoLC taking into account capital costs and operating costs over a 30 year period.
Omission of Pumped Drainage
To facilitate the removal of a rail/road level crossing, it was necessary to lower the road under the railway.
Through hydraulic modelling and optimisation of the road/rail vertical alignments it was possible to revise the hydraulic design to enable gravity drainage of the storage tanks directly into the stormwater drain.
By doing this, savings in WoLC of over $3.5 million were achieved. In addition, the solution was safer to construct and maintain.
The Use of LED Lighting for Station Car Parks
High efficiency lighting has been provided in all station car parks. Light-emitting diode (LED) luminaires were utilised to provide a low energy and low maintenance solution. The lighting is controlled via a time clock which is linked to a photo sensor to optimise energy savings.
This proposed solution achieved a WoLC saving of approximately $200,000. This strategy also provides a
benchmark for future sustainable lighting design for station car parks across the metropolitan rail network (see Figure 7).
Delivering a new 21st century railway in an existing live brownfield railway environment presented unique design and construction challenges. Significant constraints constantly challenge project teams such as keeping the existing railway running, minimising disruption to passengers and the public, maintaining businesses and the adjacent road network during construction, and balancing the needs of the vast array of stakeholders involved.
There are many factors which have contributed to this project being well on its way to success including:
- Delivery using the alliance method of procurement resulting in stakeholders being intimately involved in all aspects of the project and striving for excellence.
- Pooling of best practice from around the globe in both design and construction methods.
- Innovation in design and construction.
- Designing with the end user in mind so that maintenance costs are reduced.
- Ensuring that the finished product is not only robust but will be appealing to the public.
Finally, the safety initiatives employed on the project through innovative design and construction techniques have resulted in extremely positive results during the delivery phase. Over four million man-hours were worked on the project and the reported lag indicator statistics of safety performance were considered groundbreaking in the industry for a project of this size and complexity.
As well as providing additional services now, Regional Rail Link provides the capacity for more services as the population grows and the demand for public transport increases, thereby improving the “urban future” of Victoria.