SubscribeCreating the Work Breakdown for estimating the capital cost of a Light Rail Transit Project includes Civil, Roadwork, Building, Railwork including Traction Power, Tunneling and Shoring.
Virtually all Light Rail Transit Projects are constructed in heavily populated metropolitan areas and are designed to alleviate traffic congestion in downtown areas and usually include provisions for managing or detouring traffic. The main civil components of the project usually include specialized shoring techniques, and often involve both cut and cover or bored tunnelling methods. Some Light Rail Projects also include for supply of the Transit Vehicles, also referred to as Rolling Stock. The success of Light Rail Transit Projects usually revolves around the efficient shoring techniques, traffic management and the proper management of Traction Power and Traffic Signalling.
Phases of Light Rail Transit Projects
Light Rail Transit Capital Cost Estimates can be broken down into distinct sections;
- Traffic Management
- Pavement Removals
- Utility Relocations
- Roadwork
- Shoring
- Tunneling
- Street Lighting
- Trackbed
- Trackwork
- Traction Power
- Power Distribution
- Transformer Stations
- Signalling System
- Automated Vehicle Locator Systems (AVLS)
- Ticketing and Fare Collection Systems
- Light Rail Transit Vehicles
- Maintenance & Operations Facilities
- Maintenance Equipment
Traffic Management
Light Rail Transit Systems usually have to interface with other modes of transportation on shared rights of way. The track-beds can be separated or shared with automobile and bus traffic. A crucial component of the estimate breakdown is the traffic management, detour construction and traffic staging.
Utility Relocations
Because the alignment of the Light Rail Transit System is found in older built up metropolitan areas, the relocation of existing utilities can become a major component of the overall cost. Space and right of way is often limited making these relocations very expensive.
Shoring
Quite often if the trackbed or stations are located underground, costly shoring is required. The shoring may have to be constructed tight up against buildings or against heavily traveled pedestrian areas. Sound regulations may also be a factor that drives the selected shoring techniques. Quite often walls are cast directly against the shoring. In the case of tangent pile shoring techniques the shoring becomes the wall of the station.
Tunneling
Complicated tunnelling, often including work in soft ground or mixed face conditions can be found on Light Rail Transit Projects. Tunnels have to be constructed deep enough to avoid existing utilities and building foundations. Dewatering can also create issues with drawdown of the water table which may effect building foundations.
Trackbed
Light Rail Projects usually require different trackbeds than traditional railway construction. Traffic, drainage, maintenance and aesthetics usually dictate that the rail be fixed to a concrete base. If the right of way is to be shared with other vehicles then the tracks must be in-filled with either concrete, asphalt or paving stone. Special rail features are incorporated to handle drainage issues.
Trackwork
Special grooved rail with heated turnouts and drainage boxes are required. Special switch machines and multiple crossovers are also the norm.
Traction Power
Virtually all Light Rail Transit Systems are electrically powered. The construction of substations would be required including transformers, rectifiers, DC and MV Switchgear. The power is often distributed overhead to the transit vehicles via catenary poles and cable systems.
LRT Signalling System
Because Light Rail Vehicles often share rights of way with other vehicles, a sophisticated signalling system will be required. This includes the supply and installation of Interlocking Equipment, Central Train Control Equipment and Train Borne signalling equipment.
Supervisory Control Systems
LRT Systems are often controlled remotely from a central operations centre. The control systems usually include a Central Automated Vehicle Locator System (AVLS), on board AVLS equipment and Passenger Information Systems.
Ticketing and Fare Collection Equipment
For collecting fares the ticketing and fare collection equipment must also be included in the estimate. This includes validation equipment, ticket vending equipment and central computer hardware.
Light Rail Transit Vehicles
The Light Rail Transit Vehicles or Rolling Stock can cost upwards of 30-40% of the capital cost of the projects. These electrically powered tramcars can also include specialized features such as Passenger Information Systems, CCTV systems, passenger counting systems, wheel chair ramps and special security systems. Special rail mounted maintenance equipment may also be required including rail grinding vehicles, rescue vehicles and tower rail-road vehicles.
Maintenance and Operations Facilities
These facilities usually include maintenance shops, administration facilities and an operations and control centre. The maintenance facility can include special trackwork to move the equipment around as well as specialized maintenance equipment and tools. The operations control centre (OCR) includes computerized work stations and may include a specialized video wall. Specialized security and CCTV systems are also required.
Conclusion
Creating the Work Breakdown for estimating the capital cost of a Light Rail Transit Project is much different than traditional building or civil projects and includes large components of trackwork, traction power and traffic management. Different from most other capital cost estimates, these projects often include for the supply of the Light Rail Vehicles themselves along with the associated operations and maintenance facilities.