Light Rail Transit Design Proposal

This assignment presents a proposal for the design of a light rail transit system. The proposed design prioritizes tangents with curves and arches incorporated where necessary, adhering to safe turning radii. The design will integrate transition curves for both horizontal and vertical elevation changes. Technical specifications will align with Australian Light Rail Regulated Electrical Utility Network Code of 2016. Simulation testing using PLM will precede construction of a test section followed by final design and certification.

System Science And Engineering Management
Name
Date

Contents
Executive Summary..............................................................................................................................3
Introduction..........................................................................................................................................3
Preliminary Design...............................................................................................................................4
Detailed Design and Development.......................................................................................................5
System Test, Evaluation and Design Optimization..............................................................................6
Conclusion............................................................................................................................................8
References............................................................................................................................................9

Executive Summary
A proposal for the design and development of a light rail system that will be an extension to the
existing Inner West Light Rail (also called the L1 Dulwich- Hill Line that will have 15 stopovers is
made. In the preliminary design, a series of tangents and curves are proposed to ensure safety and
comfort. The stations will be between 45 and 60 feet long though 75 feet is desirable. In the detailed
design, requirements for track radii at curves and vertical curves are used as a basis for the design.
The train is envisaged to have a speed of at least 24 km/h’ a formula guided the design parameters.
The Australia Light Rail Regulated Electrical Utility Network Code of 2016 requirements is strictly
complied with, along with other technical and operational requirements. The proposed system will
then be tested and evaluated and design optimized using simulation software for engineering design.
Introduction
In this project, a proposal has been made for the design and development of a light rail system that
will be an extension to the existing Inner West Light Rail (also called the L1 Dulwich- Hill Line.
The new light rail system will serve the Parramatta region of Western Sydney and is aimed at
improving transport in the system and reducing the rising traffic levels in Sydney. The light rail line
will run from Carlingford through the central business district of Parramatta and on to Westmead
via the Pennant Hills, a distance of 8.6 kilometers (the light rail will be 8.9 km though). This is a
major project that will cause significant disruptions, but is ultimately aimed at improving transit

times within the slated route and helping with redevelopment and regeneration of various regions
along the light rail line. Having made the initial rail transport proposal for the Carlingford-
Westmead light rail through Parramatta, this paper is a critical analysis of the proposed design and
design concepts, along with a detailed analysis of the design for the light rail line. After this
introduction, the paper will discuss at length the preliminary design, justifying the design cues used.
The design will then actualized and in depth critical analysis of the detailed design and development
of the light rail line. This will be followed by an analysis and discussion of the tests for the system,
along with its evaluation and optimization of the design. The report will then end with a conclusion
Preliminary Design
The first area of design is for the track and how it will be laid out; this section will focus only on the
design principles for the track and not delve into the materials used for laying the light rail track. In
the preliminary design, it is proposed that a series of tangents (straight lines) or rail track be used
where permissible, and be joined by arcs and curves in the light rail system. The light rail is aimed
at ensuring high speed, but safe transport system (Jingjing, Changjiang & Ming 2013) (Vuchic,
2007). The concerns for the design include fast, safe and comfortable city transport, at an affordable
cost; the main driver for the design is rapid transport. The light rail system is slated to have up to 15
stop overs along the way, which implies that a lot of time will be lost during scheduled stops along
the light rail line. This therefore informs the need for the use of tangents as much as possible along
the line. This will ensure that the light trains can achieve high speeds to enable rapid transit and
achieve the goal of rapid transportation, while also compensating for the time inevitably lost during
scheduled stopovers (Parsons, Brinckerhoff, Quade & Douglas, 2012).
The tangents will also ensure comfort and safety for the travelers. The curves and arches used to
joining the tangents will enable continuity, but inevitably, are areas in which the light rail will lose
speed and slow. However, the design principles require that the curves also enable sufficient speed
while retaining safety and comfort features (Hoel, Garber &Sadek, 2011), (‘Mitre Corporation,’
1996). The minimum curve radius for light rails and railway lines will be maintained along with
light rail elevation so as to maintain safe speeds in the curves. The light rail vertical curves are
informed by the envisaged safe speed and comfort, along with cost implications and the
geographical conditions along the light rail path. Between the tangents and the main curves,
transition curves will be incorporated into the design because curves should not suddenly become
straight. Instead, transition curves will be incorporated so that there is a gradual increase in radii
over time, for a distance of between 40 and 80 meters for lines where maximum speeds of 65 MPH

are possible. The transitioning will also be done for elevations and super elevation sections
(Laughton & Warne, 2003), (Hoel, Garber &Sadek, 2011).
The stop station lengths are designed based on the existing conditions, including availability of
space and the population of the areas the light train will pass through. The desirable length is 75
feet; however, it is not possible however, to have all stations being of this length. Therefore, there
will be a minimum station length, along with an absolute minimum length for the light rail line,
with the minimum length being 60 feet and the absolute minimum being 45 feet. These have been
used because of the need for a safe stop distance and based on an analysis of the specific conditions
and the urban context of the light rail system (Hoel, Garber &Sadek, 2011). The allocation of the
three station length parameters are informed by the following;
 Requirements by passengers and staff as well as the requirements for facilities
 Requirements for transfers
 Requirements for security of the people and the place, as well as the interconnecting public
spaces at the designated stations
Design considerations are made for pedestrian access and the state of the light rail routes, Vis a Vis
pedestrian and vehicular traffic. The station length is also designed based on the platform length and
the concourse size.
Detailed Design and Development
The basic design principles will be observed, starting with the curves and tangents where the
minimum radii and transitions curves as well as elevations and vertical curve requirements will be
observed. The curves joining the light rail tangents are legislated by the rolling stock’s mechanical
ability to adjust to the light rail track curvature. The guidelines for the minimum radii of curvature
will be governed by the North American standard of minimum radii of 125 meters. However, this
will be determined by the prevailing conditions so that the light trains can maintain a speed above
24 km/hr. The proposed light rail is envisaged to operate a top speed of 65 miles per hour (MPH)
where this is possible; the train will have an average weight of 54 tons. The force that trains exert
on the tracks changes when negotiating curves. For this reason, the design incorporates vertical
curves of the light rail line so that the crest curves are not too tight as if this happens; the train may
derail from the track as the track drops beneath it (Sheppard 2015). If the trough is too tight as well,
the train can plough downwards into the rails, causing damage/ and or an accident. The vertical
curves are therefore designed based on the supporting force principles. The support force [R] the

train exerts on the track as a function of its mass [m], radius [r], and speed [v] is governed by the
relation;
R = mg +- mv2/r
The + is for troughs and the – for crests. To ensure passenger comfort, the g (the gravitational
acceleration) as a ratio to the v2/r, the centripetal acceleration must be kept as small as is possible to
ensure passengers don't feel ‘large weight changes’ (Abe 2004).
 The proposed design of the power to weight ratio for the light rail is between 9 and 9.5 (HP
per ton) The light rails will have a length of about 90 Ft. (articulated) that can carry 160
passengers at one go. The train will use electric propulsion
 For ease or embarking/ disembarking, the light rail system will be designed to be a low floor
train system and have sufficient ground clearance
 The light rail must observe clearance from other facilities and circuits/ structures, in which
case the minimum clearance as stipulated by the Australia Light Rail Regulated Electrical
Utility Network Code of 2016.
 The separations and clearances with regard to other structures must comply with the parts 2
and 3 of Public Safety Utility networks Regulation of 2001 based on the Utilities Act 2000.
 The overhead electric line designs must also comply with the AS/NZS 7000 section 3
Overhead line designs with the detailed procedures followed and the EN 50122-1
applications for railway, electrical safety, return circuit, and earthing; this is to ensure there
are sufficient provisions to protect against electrical shocks.
 A survey will be undertaken before design and follow the relevant city and national survey
rules.
System Test, Evaluation and Design Optimization
A prototype system will be tested with a small electric train on a small section of the light rail line
after it is put in place. Heavy gauge steel will be used for the train lines and tested for safety during
operation and hazards.
 Tests will be done to conform to the Australia Light Rail Regulated Electrical Utility
Network Code of 2016. The tests will include electrical safety, electromagnetic interference
and compatibility, and stray current, governed by the stray DC (direct current) working
group guidelines.
 Test will also entail conformance to the technical requirements as stipulated by the Australia
Light Rail Regulated Electrical Utility Network Code of 2016.

 Technical analysis will be submitted to authorities with each technical issue referenced and
an operating technical certificate will be hopefully given by the technical regular.
 An emergency plan will be put in place based on the Australia Light Rail Regulated
Electrical Utility Network Code of 2016 technical requirements and references (Corbel
2016)
 Because of the scale of the project and the cost, the design team will use modern design
software, including the use of BIM (building information modeling) for the structures and
Auto CAD (Mahdjoubi, Brebbia & Laing, 2015) as well as simulation and testing software
(PLM by Siemens) to evaluate the design and performance before any physical work is done
(Madsen 2017).
The simulation and other tests and technical assessments based on the design will then be evaluated
and adjustments made based on simulation software performance. Adjustments and optimizations
will then be undertaken using the design software and design parameters, along with performance
based on the simulations. The PLM software will provide near real life simulations for accurate test
results. The tests will entail testing of the light rail track, starting from weight and force exerted by
the vehicle tests. These will conform to the general and detailed design principles discussed earlier
along with performance under different conditions based on the rail design (Madsen & Madsen
2017). Special attention will be placed on cornering and speed, as well as vertical curves
performance where forces will be measured with respect to the safety and comfort thresholds. This
testing phase is crucial in ensuring that the light rail system conforms to existing safety standards
and technical requirements and is designed in such a way that future advancements in vehicle
design will not require changing the light rail tracks.
Evaluation will look closely at external factors, including existing traffic patterns on the proposed
light rail track, its elevation, along with pedestrian traffic and existing facilities and assets such as
power and other utility lines.
 Station access and exit areas, along with the pedestrian access points and existing traffic will
be evaluated for conformity to the technical standards. After these steps, test lines and a light
electric wagon are used for actual tests based on improved designs after the simulation tests
and technical reviews.
 Tests will be vigorous and any adjustments made before final designs are proposed and
made and sent for approval.
 The extensive tests and technical and performance evaluations are crucial for meeting the
objectives of the project of rapid transit between the two areas; Carlingford and Westmead,

via Parramatta, in a safe and comfortable manner. The design also takes into consideration
cost structures and the desire for a cost effective light rail system that is easy to maintain and
manage.
 The design will incorporate BIM principles and applications for the life-cycle management
of the Carlingford-Westmead through Parramatta light rail system (Corbel 2016), (Madsen
& Madsen 2017).
Conclusion
A proposal has been made for the construction of a light rail system between Carlingford and
Westmead through Parramatta that will have up to 15 stops. The design and detailed design are
guided by safety operating principles along with technical requirements and the constraints of time,
money, and resources. The proposed general design is to have as many tangents as possible and
where inevitable, curves and arches are used the radii and safe turning principles followed.
Connecting every curve and tangent will be a transition curve that will also be employed in vertical
elevation design. The relation between speed, curve, weight, and force will be used to design the
curves and arches. Minimum and absolute minimum requirements for stopping and station designs
are to be incorporated. Technical requirements based on the Australia Light Rail Regulated
Electrical Utility Network Code of 2016 will be strictly observed and the design tested in a
simulated environment using PLM, before adjustments made. A test section will be built and further
tests done, before a final design for the whole length of the rail line is made and relevant
certifications sought. It is recommended that this project gets a green light and proceeds to the next
phase of design and simulation testing

References
Abe, M. (2004). The dynamics of vehicles on roads and on tracks: proceedings of the 18th IAVSD
symposium held in Kanagawa, Japan, August 24 - 30, 2003. London, Taylor & Francis.
Corbel, S. (2016). Utilities (Technical Regulation) (Regulated Utility Coordination Code) Approval
2016. [ebook] Sydney: Australian Capital Territory, pp.2-7. Available at:
http://www.legislation.act.gov.au/di/2016-18/current/pdf/2016-18.pdf [Accessed 30 Sep. 2017].
Hoel, L. A., Garber, N. J., & Sadek, A. W. (2011). Transportation infrastructure engineering: a
multimodal integration. Stamford, Cengage Learning.
Jingjing, C., Changjiang, Z., & Ming, Y. (2013). Research on Rail Transit Network System and its
Connection Model in the Metropolitan Area. Procedia - Social and Behavioral Sciences. 96, 1286-
1292.
Laughton, M. A., & Warne, D. F. (2003). Electrical engineer's reference book. Oxford [England],
Newnes.
Madsen, D. A., & Madsen, D. P. (2017). Engineering drawing & design. Australia : Cengage
Learning
Mahdjoubi, L., Brebbia, C., & Laing, R. (2015). Building Information Modelling (BIM) in design,
construction and operations First International Conference on Building Information Modelling
(BIM) in design, construction and operations.WIT transactions on the built environmentv149
‘Mitre Corporation’. (1996). Intelligent transportation infrastructure benefits: expected and
experienced. Washington, DC, U.S. Dept. of Transportation.
Parsons, Brinckerhoff, Quade & Douglas. (2012). Track design handbook for light rail transit.
Washington, D.C., Transportation Research Board.
Sheppard, M. (2015). Essentials of urban design. Clayton, Vic. CSIRO Publishing
Vuchic, V. R. (2007). Urban transit systems and technology. Hoboken, N.J., John Wiley & Sons.
http://app.knovel.com/hotlink/toc/id:kpTDHLRTEL/track-design-handbook.