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OCR for page 46
Baggage Make-up Model Baggage make-up includes manual or automated make-up units, the cart/container staging areas, and baggage tug/cart (baggage train) maneuvering lanes. The type of system selected for a terminal depends on a number of factors including the number of airlines, the terminal config- uration, operating policies (common use, exclusive use), and size of the terminal complex. Although checked baggage ratios are a consideration, especially when designing more compli- cated automated sortation systems, these ratios generally affect the total number of baggage carts/containers in use rather than the size of the make-up area. The number of carts/containers per flight staged at any one time, however, is generally based on the size of the aircraft. For most terminals, one cart or container is typically staged for each 50 to 75 seats of aircraft capacity; this would be equivalent to approximately two to three carts/containers per EQA (1 EQA = 145 seats). A cart or LD3 container is usually assumed to have the capacity for 40 to 50 bags. The number of staged carts/containers can also vary based on individual airline policies for pre-sorting baggage at the spoke airport for more efficient transfer at the hub. An airline may start moving carts/ containers to the gate as they fill up when more than two or three are used for a flight. The total number of staged carts or containers also is related to the passenger arrival time distributions and how early an airline staffs the make-up area. Typically, domestic flights begin staging carts two hours before scheduled time of departure (STD). International flights typically begin at three hours for early departing flights (between 4 and 9 a.m.), and four hours for other departure times. For passengers who check in before these normal time periods, some type of early bag storage may be required. The baggage make-up process is typically finished 30 minutes prior to STD, but can extend closer to STD for smaller airports. To determine the number of staged carts or containers, the planner should estimate the peak number of departures during the two-, three-, or four-hour period (as appropriate for the termi- nal's type of service) and apply the appropriate aircraft size mix (or use EQA). The Baggage Make-Up model estimates the make-up requirement based on the total EQA of gates in use, the average number of departures per nominal gate (not normalized to EQA) in the make-up period, and the likely number of staged carts/containers required per EQA. The EQA value can be linked to the Gate Demand model, but can also be entered manually. The user will then estimate the expected number of departures per nominal gate during the make-up period. The make-up period for domestic flights is typically around two hours and may be up to four hours for an international flight. The average make-up period will depend on the type of service provided at the airport and the mix of markets that are served. The estimated value to be entered should reflect the number of departures per gate that will require baggage staging for those flights during the make-up period. Once the period and expected departure rate is determined, the user will need to choose how many carts/containers are likely to be staged for each flight, as described above. 46

OCR for page 46
Baggage Make-up Model 47 EQA based on # of Staged Bag Make Up Area Gates In Use Carts/Containers Area for Bag Make Up and Baggage Make Up Area Allowance for Circulation Baggage Train Circulation Figure 59. Baggage make-up area modeling methodology. The size of the baggage make-up area will vary depending on the type of make-up units (index belts, re-circulating make-up units, sort piers, etc.) and whether the systems are exclusive or common use for typical configurations and dimensions. For preliminary planning purposes, the area per staged cart/container typically varies from 600 square feet/cart for individual airline make-up areas with re-circulating make-up units to 300 square feet/cart for larger pier make-up areas. These areas exclude conveyor tunnels or extensive sortation systems. In addition to the area for baggage make-up and bag claim off-loading, most terminals need additional lanes and other common-use maneuvering areas that link the inbound and outbound baggage handling areas to the apron. For programming, a 10% to 15% allowance of all baggage handling areas will generally be sufficient for tug circulation in a two-level terminal, provided the terminal config- uration is reasonably efficient. Figure 59 shows the overall method used to determine the baggage make-up area. The alternative ratio method uses a general rule-of-thumb approach based on the average make- up area in relation to total EQA. Generally, 1,500 to 2,200 square feet per EQA of overall make-up area is the range at airports that have been studied. By using actual current space allocation and physical dimensions, the user can calculate the current ratio at a specific airport, which may then be used to project future requirements. This result is also a good measure for comparing to the results from the first method. Figure 60 is a screen print from the model showing the linked EQA cell and the five required input cells for the first method, and only one required input cell for the alternative ratio method. Figure 60. Baggage Make-up model.