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110 The focus of the guidebook to this point has been the plan- ning and implementation of new APM systems at airports. This chapter focuses on existing APMs that need to be either expanded or overhauled. System expansion may range from (1) a simple increase in fleet size to (2) an extension of the guideway alignment, with new and/or lengthened stations, upgraded train control elements, and perhaps additional vehicles/trains. Similarly, an APM system overhaul can range from (1) a refurbishment of a single subsystem (i.e., station doors) to (2) a full replacement of multiple subsystems (vehi- cles, train control, switches, etc.). The two typical passenger conveyance needs that require an increase in APM services are (1) an increase in passenger demand and (2) the introduction of new facilities to be served by the system. Thus, to differentiate meaning in the text, the following convention is used: â¢ Fleet expansionâThe term âfleet expansionâ is used to denote the addition of vehicles into the fleet and/or recon- figuring the fleet and associated system facilities to accom- modate longer trains. â¢ System extensionâThe term âsystem extensionâ refers to a physical lengthening of the system, which involves all of the physical elements of the system (guideway, switches, stations, etc.) and may involve additional fleet. 12.1 APM System Expansion and Extension Planning An important consideration in determining when an APM expansion is warranted is the performance of the existing fleet. The research produced from ACRP Project 03-07, âA Guidebook for Measuring Performance of Automated Peo- ple Mover Systems at Airports,â should be a useful reference on this topic. The need for expansion and/or extension of an APM system is driven by the same set of parameters that gov- ern the need for a new APM system. These aspects are dis- cussed in Chapters 5 and 6 of this guidebook. Fleet Expansion A fleet expansion is typically required by an increase in pas- senger demand on an existing APM system, necessitating an increase in system capacity. Capacity can be increased by increasing the frequency of trains (reducing headway) or by increasing the length of trains (vehicles per train), or by a combination of both. Assuming the system is operating at maximum capacity, in all of these cases the size of the fleet and the amount of fleet maintenance (and perhaps MSF size) will be increased. System Extension APM extensions involve adding more guideway to serve a new station or stations. Such extensions will necessarily include new guideway and associated wayside equipment (power rail, control elements, switches) as well as station equipment. Phys- ical extensions of APM systems may involve adding vehicles, but this is not necessarily the case; it is possible that sufficient vehicles may be available in the existing fleet to serve the longer system. If not, new vehicles will have to be purchased. Finally, depending on the details of the extension, the MSF may need to be enlarged and/or relocated. The impacts of an APM fleet expansion or system extension on the different subsystems are depicted in Figure 12.1-1. Whether an APM fleet expansion or a system extension is under consideration, the review of options and selection of the best approach is a multi-step process. The steps of this process are as follows: 1. Alternative development, 2. Alternative evaluation, C H A P T E R 1 2 System Expansion and Overhaul
3. Review of preferred alternative and comparison with no-build, 4. Development of the implementation plan, and 5. Decision making and appropriate approvals. 12.1.1 Planning for APM Fleet Expansion An increase in the APM system capacity requirement necessitates a fleet expansion. The complexity of a project for fleet expansion depends on the type of expansion and the pro- visions that were made for such expansion in the original sys- tem. For example, the expansion could involve just adding a vehicle to existing trains. This could be a simple step if the sta- tions and controls were originally sized to accommodate the longer trains, or it could be more complicated if no advance provisions were made. Further, adding additional vehicles could necessitate system changes and be quite involved, as when a shuttle system is modified to a pinched-loop system to allow more trains to operate. When expanding the capacity of an existing APM, a com- prehensive review and understanding of the existing system is critical. The following system characteristics should be avail- able or gathered: â¢ Ridership, â¢ Peak period/non-peak period operations, â¢ Stakeholder concurrence and definition of acceptable impacts on level of service, â¢ Existing train length and designed ultimate train length, â¢ Existing facilities and their compatibility with the new larger fleet or increased train length, and â¢ Existing APM control and safety features (to evaluate any added requirements and upgrades that may be needed for the new train numbers and/or configuration). The planning team for a fleet expansion project must understand the existing operational plan and must review and evaluate its potential degradation/interruption during the expansion work. By evaluation and analysis, a decision must be made regarding whether to subject the system to operational interruptions or to provide alternate means of transportation for passengers during expansion work activi- ties. This becomes a tradeoff between impacts to passengers versus impacts to the schedule (and cost) of construction. 12.1.2 Planning Criteria Involved in Fleet Expansion A number of APM facility and facility-related issues are crit- ical and should be considered when planning a fleet expansion project involving more or longer trains. These facilities and issues are described below. Station(s)âDetermine if the existing station is ready for longer trains. Facility elements such as platform length, platform station doors, and dynamic signs must be eval- uated. Additionally, the station platform size and layout must be analyzed to determine that it can handle addi- tional passenger demand due to more frequent and/or larger trains. A NFPA analysis of passenger emergency egress from the station is typically required unless already provided and planned for in the original design. GuidewayâTypically, very few guideway changes are required if the fleet expansion involves only adding vehi- cles. If longer trains are involved, the system safe stopping distances and related control systems may require review and design level re-analysis. If the fleet expansion involves changing from a shuttle system to a pinched-loop sys- tem, new crossovers and switches will be required. This will require layout and placement of switches and cross- over guideway, with appropriate rework in the guideway layout. System equipmentâFor projects involving longer trains, the various subsystems involved with train movements must be analyzed to ensure that they can safely handle the longer trains; switches, power distribution, train 111 Station MSF Requirements Fleet Length Number Size Site1 Guideway ATC PDS Fleet Expansion Increased Freq. Longer Trains System Extension Same Capacity Increased Capacity Key: = Expand = Possible Expansion = No Expansion Note: 1 For the MSF site = change of site, = potential change of site, and = no change of site. Source: Lea+Elliott, Inc. Figure 12.1-1. APM expansion/extension subsystem impacts.
control, communications, and other similar subsystems must be investigated for adequacy. Maintenance and storage facilityâAn MSF analysis should be made to confirm the need for additional MSF space to support a larger or reconfigured fleet. Also, the operational procedures in the MSF should be reviewed to determine if changes need to be made. Finally, in some cases fleet expansion may require additional MSF space. ProcurementâFleet expansions are typically supported by the existing APM supplier under a sole-source con- tract. However, in some instances where the existing technology is obsolete, the original supplier has been engaged to replace the old technology with updated equipment. If this is the case, additional costs may be necessary to modify the system to accept the new tech- nology. ImplementationâThe airport planner involved with an APM expansion should have an understanding of the implementation issues associated with the project. This is important for planning the work and establishing a suitable project schedule and cost. System testing periodâA detailed test and acceptance period is required at the conclusion of any work affect- ing the configuration and/or operation of an APM sys- tem. This is necessary to ensure that passenger safety is not compromised. Therefore, adequate time for testing and verification of all work must be included when developing the total time for implementing the APM fleet expansion. 12.1.3 Planning for a System Extension Some of the issues involved in planning the extension of an existing APM system are the same as for a fleet expansion. For example, data describing the existing system technical char- acteristics and operation must be available or gathered. See Section 12.1.1 for a list of such data. In addition, other information and data related to the physical extension of the system needs to be available or developed; this information is critical to understanding the existing APM system and defining methods for accomplish- ing the extension work with minimal impact: â¢ Tie-in location(s). The tie-in location is where the new extension guideway will join the existing guideway. Any work in this area will impact the existing system and must be coordinated with day-to-day operation and mainte- nance activities. â¢ New area(s) to be served. A plan of the additional facilities to be served will facilitate layout of an appropriate guide- way extension alignment. â¢ New station service locations. Within the new facilities, a determination of where service is desired. â¢ Characteristics of new passengers. Are the APM riders air- line passengers? If so, what kind(s) of passengers are they, and what separation is required? Are employees involved? Must they be kept separate from passengers? As with a planned fleet expansion, the planning team for a system extension project must understand the existing oper- ational plan and must review and evaluate its potential degra- dation/interruption during the extension work. By evaluation and analysis, a decision must be made regarding whether to subject the system to operational interruptions or to provide alternate means of transportation for passengers during extension work activities. This becomes a tradeoff between impacts to passengers versus impacts to the schedule (and cost) of construction. 12.1.4 System Extension Configuration and Implementation For an APM extension there are a number of facility and equipment issues that are critical and should be analyzed when planning the project. Many of the considerations are the same as for a fleet expansion; see Section 12.1.2. In addi- tion, the following additional issues should be evaluated: VehiclesâAnalyses of the longer systemâs operation must be made to determine the additional number of vehicles that must be placed in the system to serve the additional stations and passengers. Consideration should also be given to the appropriate configuration of the trains; is the same train size sufficient, or are longer (or shorter) trains in order? Although such issues may be addressed manually, it is much better if a computer simulation of the complete new system can be made. Station(s)âStation location and layout should be consis- tent with the rest of the system to ensure the passengersâ uniformity of experience. Also, the new stations should be well-integrated into the facilities they serve. All of the wayfinding, size, and service issues identified for new stations in Chapter 8 should be addressed. GuidewayâThe layout of the new system guideway is crit- ical in developing a seamless and efficient connection between the existing system and new extension. The lay- out and the exact guideway geometry should consider multiple criteria, including location of the end of the existing system, the preferred location of the station(s) in the new facility, physical space and right-of-way for guideway alignment, and constructability and cost issues (aboveground or underground). For feasible guideway layouts, the evaluation should compare the one-time 112
cost of construction with the recurring costs of longer round-trip time, larger fleet, and higher power consump- tion for a sub-optimal alignment. Also see Chapter 8 for information related to planning new guideway align- ments and layouts. System equipmentâFor system extension projects, the various subsystems involved with train movements must be analyzed to ensure that they are still appropri- ate for both the old and new parts of the system. If new and/or longer trains are contemplated, then the per- tinent subsystems must be analyzed relative to the new/ longer trains to be sure that safety is not compromised; switches, power distribution, train control, communi- cations, and other similar subsystems must be investi- gated for adequacy. Maintenance and storage facilityâAn analysis should be made to establish the need for additional MSF space to support a larger fleet as well as to identify any changes in the maintenance function/procedures for the expanded system. The location of the existing MSF should be ana- lyzed; an APM extension farther away from the MSF could impact the existing operational processes and effi- ciencies. These issues should be analyzed and additional MSF space/locations identified, if required. ProcurementâIt is typically assumed that all extensions are supported by the existing APM supplier under a sole- source, negotiated contract. However, it should be noted that there are some cases where an extension project has involved a different operating system. A complete change of operating system (and supplier) typically requires additional capital costs to adapt the system to the new technology. These costs may be offset by the competitive aspects of procurement by bid rather than sole source. ImplementationâThe airport planner involved with an APM system extension must have an understanding of the implementation issues associated with the project. This is important for planning the work and establish- ing a suitable project schedule and cost. System testing periodâA detailed test and acceptance period is required at the conclusion of any work affect- ing the configuration and/or operation of an APM sys- tem. This is necessary to ensure that passenger safety is not compromised. Therefore, adequate time for testing and verification of all work must be included when developing the total time for implementing the APM system extension. 12.2 APM System Overhaul This section describes the planning and implementation issues associated with an APM system overhaul. APM system overhauls are sometimes referred to as refurbishments. For the purposes of this section, it is assumed that the APM to be overhauled is providing an essential function and cannot be shut down and must remain operational to provide passen- ger service for the duration of the work. The information provided herein is intended to aid airport planners in planning APM overhaul projects. However, due to the proprietary nature and complexity of APM equipment, planning for modifications and overhaul of existing APM sys- tems typically requires an in-depth knowledge of the equip- ment subsystems and their operation. For that reason, it is recommended that planning for APM system overhauls include input from knowledgeable system engineers. The various subsystems that comprise an APM system have varying design lives, also known as useful lives. Such durations would typically be specified in the APM systemâs initial pro- curement. There are numerous factors that go into the devel- opment of a design-life duration for a given project. Therefore, a general listing of typical subsystem design-life durations with very specific numbers of years would not necessarily benefit the airport planner of an APM system overhaul. Certain APM subsystems, such as central control and ATC subsystems, are sometimes replaced prior to the specified design life due to rapid innovations in control system tech- nologies (e.g., microprocessor speeds). This innovation typi- cally leads to an accelerated obsolescence, since it is generally more desirable to upgrade computer/microelectronics com- ponents with new technology than to repair old technology. 12.2.1 Identification of Needs and Constraints The first step in planning for overhaul of an existing APM system is the identification of near-term, mid-term, and long- term system requirements. Typical planning considerations include future passenger demand, level-of-service, and budget considerations. An additional major challenge in planning an overhaul is determining project constraints, including physical facilities, accessibility, operational, and so on. A major constraint may be the need to provide continuing passenger service. In this case, a determination must be made as to the acceptable level- of-service degradation that is permissible while the overhaul takes place. Typically the acceptable level of degradation is not a single value but varies throughout the day and may vary between seasons of the year. For example, there are typically nighttime hours when there is very little airport activity and when the APM can be completely shut down. In addition, many airports experience a seasonal peak when no degrada- tion is acceptable, while some degradation of service is accept- able at other times of the year. These issues require significant airport input in the planning process. Another potentially sig- nificant project constraint may be the requirement to afford 113
non-overhaul work periods when system maintenance can be performed. It is sometimes difficult to establish an acceptable level of degradation without also considering the associated costs for maintaining higher-order services. Typically the greatest cost is associated with the least degradation. Therefore, the level of degradation is one of the primary cost drivers that must be determined in planning system overhauls. Once the level of acceptable degradation is established, overhaul alternatives can then be explored. The identification of post-project needs (goals) includes considerations of improvements to APM capacity, perfor- mance, level of service, reliability, efficiency, and aesthetics. The long-term need may be to expand the APM to new stations and/or eliminate obsolete or soon-to-be obsolete equipment. The constraints associated with these long-term needs include the airportâs available budget (both capital and operations and maintenance) and coordination with other facility projects. To verify the safety and operational reliability of an over- hauled APM, significant testing will be required. Where sys- tem overhauls are conducted concurrently with other facility work, the conduct of system testing must be coordinated with other ongoing projects. During the construction phase of an APM extension, work areas can typically be shared between the APM contractor and other contractors. However, toward the completion of the APM overhaul, the system must be secured against all access by non-APM personnel so that oper- ational testing can be conducted. This is a significant con- straint that must be considered when coordinating with other related projects. 12.2.2 Overhaul Approaches When considering an overhaul of an existing APM sys- tem, there are two primary approaches. The first approach involves replacing the existing technology with identical or next-generation versions of that technology. This approach is typically conducted by the same supplier as the original system. Also, this approach typically involves phased instal- lation of the new equipment that is procured sole-source from the manufacturer. The other primary approach is to replace the existing APM equipment with a new or significantly different technology. This can often best be accomplished by overlaying the new system equipment over the old, switching between the sys- tems to facilitate continued passenger service, and installing, verifying, and commissioning the replacement equipment. Historically, the system overlay approach has typically been used for train control systems and vehicles. In such cases, the original equipment is used for passenger service, while the replacement equipment is installed and tested. At that point a switch-over is made, usually in a short period of time. Subsystems such as the guideway, switches, power distri- bution, and station automatic doors are typically replaced using the phased installation approach, where one or more pieces of equipment are removed from service and a new component is then installed, tested, and commissioned. Selection of Approach The process for selecting the appropriate approach begins with the identification of the stakeholders. The group of stake- holders then considers the project objectives in light of the rel- ative costs and impacts of the two approaches. The stakeholders develop the acceptable impacts to existing APM service com- pared to the cost of maintaining full APM system capacity throughout the project. An evaluation matrix can be used whereby weightings are assigned by the stakeholders to various project parameters such as cost, schedule, level of service, tech- nical risk, and impacts to associated work. At one major airport, the stakeholders included representatives from the airlines. In this case, it was agreed that the best approach would be to select methods that minimized the impact to the APM passen- gers at the expense of extending the overall duration of the project and increasing the cost. Other airports have chosen to minimize the duration and cost of the project by accepting a greater degradation of APM service during the project. Type of Procurement In the first approach, phased implementation, equipment is usually procured through a sole-source negotiation with the existing system supplier. This is normally necessary because of the numerous proprietary interfaces between the various subsystem components. Also, the replacement equipment is typically provided by the system supplier because the supplier must be held responsible for the safe operation of the new equipment and its interface with existing equipment designed by others. A sole-source procurement typically involves the air- port first developing a set of technical requirements and pur- chasing terms and conditions. These requirements are then transmitted to the supplier with a request for technical and price proposals. Through a series of technical and contractual negotiations, the airportâs requirements and the supplierâs pro- posal are merged into a mutually agreeable contract document. The second procurement approach (overlay) is used to establish a competitive environment where two or more APM providers are invited to propose on the overhaul of the exist- ing APM. The competitive procurement is intended to pro- vide the airport with the most favorable market price for the 114
work. In this type of procurement, a complete set of technical requirements and purchasing terms and conditions are gen- erated and published by the airport, with responses solicited from interested system suppliers. In order to allow a fair eval- uation of the APM suppliersâ bids, there is usually little or no pre-bid negotiation of the contract requirements. For most APM overhauls, the airport typically would choose either competitive or sole-source for the entire system as compared to selecting competitive for PDS and sole-source for ATC. Also, even with a competitive procurement based on the overlay approach, there are some aspects of the instal- lation, such as the platform door control, that would need to be phased in (possibly with some support of the original sup- plier under a smaller sole-source contract). The overhaul approach decision should be based more on the total scope of the proprietary systems overhaul than it is on which sub- systems are to be overhauled. 12.2.3 Overhaul Technical and Schedule Considerations Planning for an APM overhaul differs significantly from that of a new APM system. The following are some special- ized areas that should be specifically addressed as part of the overhaul planning activity. Back-up transportation planâWhile most operational APMs have back-up transportation plans in the event of rare and unexpected outages, it is more likely that such an outage will occur during an APM overhaul. This is primarily due to the fact that the APM system operation is likely already degraded in order to support the instal- lation activity. Also, many APMs include special opera- tional modes for failure recovery. However, during the project some of these failure-recovery modes of opera- tion may not be available as a consequence of construc- tion activities. For these reasons, the airport must have a contingency plan to notify and guide passengers to the alternate mode(s) of transportation. This back-up trans- portation scheme should be carefully planned, staffed, and supplied with equipment so that it is capable of operating for an extended period of time. Safety certification of interim configurationsâThe cer- tification of system safety is typically addressed toward the end of a new APM installation project. However, during an APM overhaul, it is likely that there will be several interim configurations of the system. Therefore, it is important to plan for these interim system safety certifications. Configuration controlâDuring an APM overhaul, it is likely that the APM system will go through several con- figurations as old equipment is removed and new equip- ment installed and commissioned for passenger service. Since the maintenance of the APM must be ongoing throughout the project, it is essential that up-to-date documentation of the configuration at each interim phase is provided to the operations/maintenance staff. Briefings should be conducted for all O&M staff prior to any change in the system configuration to minimize the possibility of system down-time resulting from a failure. O&M staff trainingâAs mentioned with respect to the system configuration control, it is important that all O&M staff be trained in the various overhaul project phases. This training must be supported by interim maintenance manuals, which should be provided to the staff several months in advance of the training and equipment commissioning. Due to the additional time required to support both the ongoing maintenance and the training, additional O&M manpower (or overtime) should be scheduled during the project. Space constraintsâDuring an APM overhaul project there are basically two systems in operation: the existing system and the system as modified with new compo- nents. This creates a requirement to provide space for both old and new equipment. Frequently the new equip- ment is temporarily co-located with existing equipment. In such cases it is important to consider power and cool- ing capacity for the equipment rooms and spaces. The overlapping of system activities may also require that adequate spare vehicles be maintained for both existing operations and for new system testing. System availabilityâSystem availability requirements for an APM are typically specified in the contract, with financial penalties if the target availability is not achieved. Since an APM overhaul introduces new components into passenger service well in advance of final work com- pletion, an availability impact study should be under- taken in order to establish appropriate system availability levels for each phase or configuration for the project. Warranty of overhauled componentsâIn a system over- haul, various components and equipment will be placed into service at different times during the several phases or configurations of the project. For this reason, it is nec- essary to clearly establish when the warranty period for each component/equipment begins. While some air- ports accept the beginning of the warranty period as the date of passenger service for the component, other air- ports require that the warranty period commence only when the complete overhaul work achieves substantial completion. While this approach simplifies record keep- ing, it comes with additional costs because the APM 115
supplier will need to extend the equipment manufactur- ersâ initial warranty periods at its own expense. Although detailed planning of an APM overhaul project may be complex and involves numerous iterations of alterna- tive considerations, use of the guidelines and recommenda- tions described above should assist in identifying potential project risks and help ensure the success of the project while maintaining an acceptable level of ongoing passenger service. As the APM industry approaches its 40th year of successful operations at airports, there is now a track record of APM sys- tems that have operated beyond their original useful life and have been successfully overhauled. Knowledge of these over- haul projects and the lessons learned will be invaluable to any airport that is planning for the overhaul of its APM system or components. 116