SYSTEM SCIENCE AND ENGINEERING
Conceptual Design of Gold Coast Light Rail Project
The report is the continuation of the critical Analysis of the Conceptual design of the light rail system implementation in Gold Coast City of Australia.The main objective of this development project is to integrate new and existing transport system of the city to overcome traffic congestion problems.It is the part of Gold Coast Rapid Transit(GCRT) project and the main aim was to build Light Rail system to improve traffic system of the city.A detailed research at every stage of the conceptual design has been conducted to ensure safety passage of vehicles and passengers.The report includes design and construction analysis.Extensive research was done to design and minimize rail wear, track reloading and risk of derailment for better operation of the system.The strong conceptual design lead to the successful completion of different stages of the project.This report particularly reviews stage 1 conceptual design.
Gold Coast Light Rail is an infrastructure project aiming to enhance transport facilities of the city.The Gold Coast City is the sixth largest city of Australia with increasing population.The successful completion of project will provide affordable and reliable alternative to car travel and reduce traffic congestion.This will also facilitate 2018 Common Wealth games which are schedule in this city.It is divided in different stages.The final stage will terminate at Helensvale railway station.The final stage is scheduled to be completed in 2018.The objective of the project are that the new infrastructure will increase the use of public transport by the local people, and construction of new and modern infrastructures transform the city and will attract more development projects.This will also reduce car travel and traffic congestion in the city.The report is the continuation of the analysis of the conceptual design of a project.The content of the report includes Preliminary system design, detailed design and testing review.
The preliminary system design includes system specification, development and product specification, process and material specification (Blanchard and Fabrycky, 2011). A comprehensive research has been done by the (Downs, Arup and Ericksen, 2014) before construction of the project.According to the research a number of similar infrastructure were researched and new technologies were considered.A Rail and trackway specification was the outcome which is unique to this project.This included transition between different track types and supporting structure, LRT specific guidelines and wheel Rail Interface study.Some of the working features or procedure were defined at this stage for example the trams will be powered by electricity, which it draws fromthe overhead lines. Like normal trains, The tram will sit on rails, and will be guided through the city by these rails. The driver will be able to control the speed and braking of thetram.The tram will stop at all stations to pick up and dropoff passengers along the route. When the tram stops at a station, the door entry will be virtually level with the platform.All principles were considered to design the platform and the tram easy for everyone while boarding and exiting the tram.Destination boards will be made available on the tram that will inform the passengers of the next stop, and where the tram’s final destinationis. CCTV will be installed inside the tram for added passengersecurity and there will be customer service staff travellingthe route as well as at stations.Morover, the detailed light rail vehicle features, Passenger Space Allowance, Vehicle Requirements and Assumptions,Spatialrequirements and Design Issues,Service Frequency Requirements, Predicted Demand and Operational Priority are well defined and documented in the conceptual plan(Goldlinq, 2012).
Following good engineering practices the current project functional analysis process determines and compiles all the resource requirements for each subsystem and its function.Functional capability is also part of preliminary design(Downs, Arup and Ericksen, 2014).Functional analysis of all the system components is done to ensure the desired outcomes.Following are different steps in Preliminary system design:
Normally Functions can be broken down to sub functions, ultimately describing major subsystems.In this project two major sub systems are:
The different components of the first subsystem are Rail, Rail Boot and concrete slab which were designed and constructed according to the profile of the vehicles used in this system (Downs, Arup and Ericksen, 2014).Flexity 2 tram is used for this project. After deep analysis the 51R1 grooved rail profile was chosen based as it matched the preferred wheel profile of the Flexity 2 tram. To allow for future rail wear the rail is welded continuous over the project length and protrudes by a nominal 6mm above adjacent track slab top surface Procurement and Commissioning of vehicles for travel. The rails were provided with a rubber boot system.This help to isolate the rails from the track slab concrete.To reach the environment limit requirement of the project, there was a need to reduce noise and vibration from the wheel rail interface.The rubber boot system served this purpose(Downs, Arup and Ericksen, 2014).Morover, the bootedrails was cast in to plain, minimally or fully reinforced concrete slab.
- Smith Street Viaduct which spans over the Smith Street Motorway and green fields from Griffith University to the Depot Viaduct. The structure is approximately 370m long. The form comprises of 12 spans of prestressed concrete girders with a reinforced concrete deck(Downs, Arup and Ericksen, 2014).
- The second bridge is Nerang River Bridge that Carries the corridor over the Nerang River Bridge connecting Southport to Main Beach. The structure is approximately 380m long. The form comprises of 12 spans of prestressed concrete girders with a reinforced deck(Downs, Arup and Ericksen, 2014).
- The third bridge is MacIntosh North and fourth is the South Bridges that Carry the alignment over the Nerang River at two locations spanning approximately 32m and 43m respectively along the Gold Coast Highway. The structures comprise of precast concrete deck units and a reinforced concrete deck(Downs, Arup and Ericksen, 2014).
The conceptual design of this project highlights all functional charactersitics like number of travelers and speed of travel, etc.The system also fulfils the interperobility criteria as it is linked with Bus transit system part of the same development project.The project is highly sustainable in terms of saving materials and CO2 emmisions(Mcconneldowell, 2016). The trackform is designed to satisfy 40 year lifetime without any replacement or other significant maintenance.However, the rail head grinding and rail replacement can be easily done.All types of security software for both driver and passenger safety along with incident management are discussed in the conceptual plan.
According to (Blanchard and Fabrycky, 2011), the detail design and development phase requires a team approach to handle each step in different the phases of the project.In this step of system development technical engineering expertise and support along with Non-technical support that is marketing etc is required.The engineers undertook the design of project, clear and establish construction sites before starting construction activities.This also included considering impacts of construction activities on traffic, business or residential properties and formulating its mitigation strategies.Marketing of the project and operating, safety and maintenance standards are to be ensured till the completion of the project. Major construction activities included track laying and overhead, power supply, installation of control system and construction of station.The system runs Bombardier Flexity 2 Light Rail Vehicles at speeds up to 70km/hr and at a peak headway of 3.5 minutes.The track is partially integrated with the road network, therefore embedded groove rail is used.One of the requirement was to reduce construction time and material cost.For this purpose, the rail is supported by a concrete track slab and the design of track slab is based on elements of pavement and reinforced concrete slab design theories.For elevation part of track Vignle rail wit direct fixation slab track is utilized(Mcconneldowell, 2016).The differing rail profiles, track form and supporting structure required an innovative solution to the transition zone that was able to accommodate differential settlement of the supporting ground.Different studies were undertaken to ensure the safe passage of vehicles ateach stage of the projects life cycle and also minimizing rail wear, track loading and the risk of derailment.
The documentation of any construction project is reviewed and finalized by the superintended (Blanchard and Fabrycky, 2011).The complete documentation in form of different volumes is provided electronically for this project.The documents are created in Adobe Professional. The documents consists of different reports, schedules, analysis, presentation and drawings converted to PDF form.
Analytical models and engineering design tools are required for documentation and elaboration of design or other processes in a project.There are different computer tools and application for this purpose (Chakrabarti, 2002).AutoCad map is one of the tool used for different types of engineering drawings.The project documentation consists of different maps and drawing showing light rail routes and design of trackway which are designed using such tools of engineering.
12D Modeller is an Engineering design tool used for designing different components of this project.As the light rail system is occupying the existing road corridor, changes to the functionality of the road corridor was necessary(Downs, Arup and Ericksen, 2014).The detailed design of the project using the mentioned software package.It included rail, road and storm water drainage.An experts of this software were made understand the modelling requirements of this light rail system and it was found out that the existing tools in the 12D model were enough to efficiently and accurately design different phases of the project.Some new macos were designed for this particular light rail system.These macros are now part of new versions of 12d model(Downs, Arup and Ericksen, 2014).
Formal design review consists of conceptual design review which is done at the end of conceptual designing, system designed at the beginning of preliminary design, equipment and software design is done during detail design development and includes product, process and material specifications.Feedback from stakeholders and public was taken for construction of project, working hours, and disruption to traffic(GOLDLINQ, 2008).Social Impact management plan was designed and researched after completion of the concept design for this purpose.
System design review was done by (Downs, Arup and Ericksen, 2014).The development and construction of the project was according to the research and study by (Downs, Arup and Ericksen, 2014).Some changes to requirements were made as proposed by (Downs, Arup and Ericksen, 2014), as to meet the criteria of environment and design principles according to the requirements.For example minimum transition length was set to 6m in the “Scope and requirement” of the project which was changed to 13m for better transition (Downs, Arup and Ericksen, 2014).In all light rail project special attention is given to transition between track type and supporting structure and so was the case for this project.
In this phase Technical performance parameters (TPMs) must be measured to ensure compliance with specific requirements(Blanchard and Fabrycky, 2011).
This phase includes system testing and commissioning.During this phase for the case of every light rail system everything testedfrom the electrical power supply, traffic light, signaling and ticketing machines to the tramdoor buttons, information screens at stationsand on board the trams(Mcconneldowell, 2016).The first step of testing is powering up of the overhead wires and traction power substations (TPS). The next stage is the testing of traffic signals and the initial running of the trams.For this project the trams began travelling slowly to ensure all signals are working. The purpose was to help motorists and pedestrians get used to seeing trams running along the light rail corridor.The trams were later tested at operatingspeed of operational speeds up to 70 kilometres per hour(Mcconneldowell, 2016).
The GoldLinQ Consortium and Queensland Government has 8 years contract to design, build, finance, operate and maintain the light rail public transportation system(Mcconneldowell, 2016). McConnellDowell and Bombardier were responsible for design and construction of thesystem in three years period. Finally, the operations and maintenance is delivered by Keolis Downer under a 15year contract now underway(Mcconneldowell, 2016).
The successful Testing and commissioning (T&C) phase was the result of development of best-practice safety control measures and regulator standards. McConnell Dowell delivered detailed safety procedures around the Lock Out Tag Out (LOTO), Permit to Work (PTW) and Permit Recipient (PR) procedures(Mcconneldowell, 2016).These ensured that all activities within the light rail vehicle operating hazard zone were controlled and accounted forsafely.These procedures also ensured that no loss time injuries are reported during the testing phase(Mcconneldowell, 2016).
Optimization is an important aspect in the engineering design process, as it is the process of seeking the best solution for a specific design problem(Blanchard and Fabrycky, 2011).For better design and construction of the project a study was carried out by the set of researchers so that the system can guarantee lifetime success.The findings of the research are implemented in the system and published in (Downs, Arup and Ericksen, 2014).The system has achieved success through implementation of optimized solution facing all major challenges especially by constructing adjacent to five major State roads, highways and motorways, plus local roads, whilst ensuring no disruption to traffic flow of up to 32,000 vehicles per day(Mcconneldowell, 2016).
The report was critical analysis of the conceptual design(Design and testing) of Gold Coast Light rail System, Stage 1 of which is successfully running and stage 2 is expected to complete in the coming year.The project conceptual design has covered all the necessary design and testing principles, which is also evident from its successful implementation.
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Chakrabarti, A. (2002). Engineering Design Synthesis. London: Springer London.
Downs, C., Arup, B. and Ericksen, J. (2014). CASE STUDY OF RAIL DESIGN ON GOLD COAST LIGHT RAIL. Conference on Railway Excellence.
GOLDLINQ (2008). CONCEPT MANAGMENT PLAN. Concept Design and Impact Management Plan : Volume one in brief. [online] Available at: http://www.goldlinq.com.au/government-funded-early-works-resources [Accessed 19 Aug. 2017].
Goldlinq (2012). Gold Coast light rail – Fact Sheet. [online] Available at: http://www.goldlinq.com.au/resources/10-fs-howtramworks-lr-4f57794b.pdf [Accessed 1 Oct. 2017].
Mcconneldowell (2016). GOLD COAST LIGHT RAIL.