ASME RT-1–2020 pdf download.Safety Standard for Structural Requirements for Light Rail Vehicles and Streetcars.
1 SCOPE The objective of the passive safety requirements in this Standard is to reduce the risk of passenger injury and damage to equipment resulting from collision accidents by providing a means of protection when other possibilities of preventing an accident have failed. In the event of a collision, application of this Standard provides protection for the occupants of new designs of crashworthy vehicles through the preservation of structural integrity and reducing the risk of overriding and limiting decelerations. This Standard does not extend to the design of the vehicle interior structures that may help reduce injury risk caused by impact between the occupants and the vehicle interior, beyond limiting vehicle acceleration and consequential secondary impact velocity of passengers colliding with interior surfaces. In addition, this Standard provides measures for design of light rail vehicles (LRVs) and streetcars with the goal of reducing risks to street vehicles and pedestrians when involved in collisions.
4 STRUCTURAL REQUIREMENTS The carbody shall withstand the maximum loads consistent with the operational requirements and achieve the required service life under normal operating conditions. The carbody and vehicle design shall be based on the design load requirements specified in section 5. The capability of the structure to meet these requirements shall be demonstrated by calculation and/or appropriate proof- of-design testing. The vehicle is assumed to be of double-end design with an operating cab at either end. If the vehicle is of single-end design, the rear of the vehicle should be of equivalent design, and, in a collision, should respond in the same manner as the front end. The strength of connections between structural members for all structural loading requirements outlined in Tables 4-1 and 4-2 shall exceed the ultimate load-carrying capacity of the weakest member joined. For these load cases, the ultimate load-carrying capacity is defined by applying the load at the location and in the direction specified in Tables 4-1 and 4-2, but increased in magnitude to the maximum load that can be resisted by the structure, as determined by observing that further increase in deflection will result in a decrease in the load capable of being carried by the structure. References to sheathing in Tables 4-1 and 4-2 refer only to structurally related (load carrying) sheathing.
4.5 Truck-to-Carbody Attachment A mechanism for attaching the completely assembled truck to the carbody, including a the bolster if used, shall be provided, with strength levels in accordance with section 5. The strength of the attachment mechanism loaded in the vertical direction shall be as specified to secure the entire truck to the carbody when the vehicle is raised unless first intentionally detached. The strength of the attachment mechanism loaded longitudinally in a horizontal plane shall be as specified to secure the entire truck to the carbody during collisions at any possible position of the truck in its vertical suspension travel. This shall include the condition of the vehicle raised off the track with the truck hanging from the vehicle, and shall not depend upon external vertical loading nor upon bolster anchor rods. The strength of the attachment mechanism loaded laterally in a horizontal plane shall be as specified to secure the entire truck to the carbody during collisions of roadway vehicles with the side of the light rail vehicle or streetcar.ASME RT-1 pdf download.