15.3 Passenger Boarding Bridge Design Requirements
15.3.1 Slope and Code Requirements
The operation of a PBB shall satisfy American Disabilities Act (ADA) slope requirements for enplaning and deplaning passengers from each aircraft in the fleet mix for each respective gate. Each tunnel of the designed and specified PBB shall not exceed a 1/10 or 10 percent slope. At BWI Marshall the slope of each tunnel of a PBB shall be calculated by subtracting the center of cab elevation from the center of rotunda elevation, and dividing by the horizontal distance from the center of the cab to the center of the rotunda. The cab elevation shall equal the sill height of the aircraft.
Typically projects installing and/or modifying PBBs should be designed and specified to allow the operation of the PBB(s) to access the forward two (2) left passenger (L1 and L2) doors of the aircraft where applicable. However, the consultant should confirm these parameters with the departments mentioned above prior to completion of the design.
The operation of a PBB shall satisfy National Fire Protection Agency NFPA 415 requirements outlining the protection and safety of the passengers utilizing the PBB. PBB’s shall conform to Section 12.4.10 of NFPA 101 Life Safety Code.
15.3.2 Structural Analysis
A structural analysis of the PBB foundation must be performed. The design consultant shall verify the adequacy of any existing foundation for any relocations, additions, modifications, etc. For new installations, the foundation system shall be designed with the intended PBB to be used based on Step 3 above. The analysis and/or design shall be signed and sealed by a professional engineer registered in the state of Maryland.
15.3.3 Construction Technical Specification
The installation of a PBB regardless if new or relocated, shall have a Technical Specification. The standard technical Specification 347713X_Apron Drive Passenger Boarding Bridges is included in Appendix 2D - Standard Specifications. It is important to note the technical specification needs to have the following acceptance testing and pavement marking:
A. Contractor Testing Requirements
The operation of a PBB shall undergo a test for the most demanding aircraft docking procedures to ensure proper mating of the PBB to the aircraft. Temporary tape shall be utilized for the stop bar and lead-in lines for the aircraft test park. Following a successful test, the final pavement marking for the aircraft may then take place.
B. Pavement Marking
The operation limits of a PBB shall be outlined by pavement marking to indicate the limits of travel to enhance the safety of persons on the apron hardstand and protect the PBB from vehicular conflicts. The pavement marking shall consist of three (3) 6-inch wide yellow reflectorized stripes separated by two (2) 6-inch spaces. The marking shall encompass and allow for the PBB to be extended to its furthest docking position, allow for the PBB to be contracted to its storage or staging position, while providing the necessary clearances for the oversized baggage slide and other hardware attached to the PBB at all times during its swept path. The limits depicted by the marking shall coincide with the limit switches set in the PBB itself. As a result, the pavement markings shall be set in the field after the PBB operations at each individual gate have been accepted and set. The quantity of marking is estimated by the design consultant based on the anticipated PBB movements outlined above, and presented to the contractor in square footage of marking required for bidding purposes. The limits of the pavement marking shall be as-built by the contractor in the field and provided back to the engineer of record and owner.
15.3.4 Remove and Dispose of Bridge
If a bridge is to be removed and disposed, the MDOT MAA Office of Facilities Maintenance shall be notified so that usable parts can be salvaged prior to the removal (See Specification 347713X_Apron Drive Passenger Boarding Bridges in Appendix 2D - Standard Specifications).