ASME RT-2:2021 pdf free download

ASME RT-2:2021 pdf free download.Safety Standard for Structural Requirements for Heavy Rail Transit Vehicles.
The objectives of the passive safety requirements described in this Standard are to reduce the risk to passenger injury and damage to equipment resulting from collision accidents by providing a means of protection when all 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 ofcrashworthy vehicles through the preservation of structural integrity, reducing the risk ofoverriding and limiting decelerations. This Standard does not extend to the design of the vehicle interior structures that may help reduce injury risk caused by impacts between the occupants and vehicle interior, beyond limiting vehicle acceleration and consequential secondary Impact velocity of passengers colliding with interior surfaces.
1.1 Subjects Not Addressed by This Standard
There are several design considerations related to safety that are not addressed, such as, but not limited to
(a) structural repairs
(b) fatigue
(c) corrosion
(d) fire protection
(e) interior vehicle design
(f) emergency egress from vehicle
(g) inspection and maintenance
1.2 Effective Date
This Standard applies to newly constructed heavy rail transit vehicles for transit passenger service ordered 6 months following the date of issuance of this Standard by the Rail Transit Vehicle (RTV) Standards Committee and ASME.
2 DEFINITIONS
This Standard relies, where practical, on terms already In use by ASME, the American Public Transportation Association (APTA), and the Institute of Electrical and Electronics Engineers (IEEE). For the purposes of this Standard, the following definitions apply:
(c) infrequent exceptional loads, such as rerailing recovery and emergency braking, should be assessed to ensure damage does not result from their application
6 COUPLER SYSTEM
The design of the coupler system, including drawbars, draft gear. attachments to the carbody. and the carbody connection point shall respond to normal and overload conditions In a predictable manner. The coupler system shall be capable of absorbing the compression and tension forces encountered in normal vehicle operation in a train, including coupling and uncoupling, without damage.
The coupler system shall also be designed with a release mechanism to respond to compressive overload conditions. The coupler system may also include a regenerative or nonregenerative energy absorption unit(s), including portions that could be considered recoverable or easily replaceable. In a collision, the draft gear elements and/ or energy absorption unit(s) of the coupler shall compress. followed by activation of a release mechanism, which shall allow the coupler system to retract a sufficient distance to permit the carbody anticlimbers to engage. lithe collision energy is sufficiently high such that compression continues following the full retraction of the coupler system, the coupler system shall not impede the CEM response of the carbody to overload conditions. The value of the release load shall satis’ the specific characteristics of the subject transit system’s intended operation.
The coupler system shall at all times be vertically supported in a safe manner to prevent the coupler from falling onto the track. No portion of the carbody or truck components shall hinder the coupler system during its full retraction.
7 STRUCTURAL MATERIALS
Minimum material property values as defined by a material specification or standards stated in the following sections shall be utilized. The limiting static material properties shall be as given in the referenced material standard. When other standards are used, equivalency shall be demonstrated between these standards and the referenced material standards.
7.1 Austenitic Stainless Steel
Structural use of austenitic stainless steel shall be in accordance with APTA PR-CS-S-004-98 or an equivalent.
7.2 Low ALloy High Tensile Steel
Structural use of low alloy high tensile (LAHT) steel shall be in accordance with the requirements of APTA PR-CS-S-034.99 or an equivalent.