AAR is a non-profit technical association, which aims to ensure the safety, speed, efficiency, neatness and advanced technology of North American railways. Its members include the United States, Canada, Mexico and the railway freight companies of the American National Railway Passenger Transport Company. Its business mainly involves the establishment of technical services for railway freight industry standards, transportation coordination between different organizations and the research on the foundation, durability and effectiveness of railway technology. In the American railway transportation exchange service, the interchangeability and compatibility of locomotives and rolling stock and their components of each company are guaranteed by AAR's interaction rules and technical standards. A A R's standard manuals and recommended specifications are divided into three categories. Add "M" in general technical specifications, "S" in standards and "RP" in recommended specifications. The exchange rules of railway operators are mainly about the use and maintenance of equipment; The MRSP Equipment Manufacturer's Standard and Recommended Practice Manual mainly covers the mechanical properties of equipment and parts; The cargo loading rules are applicable to the loading regulations of railways, international trade and freight.
(1) exchange rules are divided into "AAR field manual" and "office manual". The Field Manual stipulates the acceptable rules of interchangeability of railway vehicles, outlines the allowable repair, penalty limitation, damage liability and dispute resolution, and lists the vehicles and parts that are prohibited from interchangeability. The Office Manual includes the fair market charging system, vehicle repair compensation, agreed time and standard of repair cost, and AAR's mechanical requirements for new, modified and upgraded vehicles.
(2)AAR standards (including technical standards and maintenance procedures) must comply with and strictly implement the technical regulations promulgated by FRA, mainly focusing on mechanical equipment performance, interchangeability, transportation standards, and electrical and train communication signals. A A R standards mainly include: mandatory specifications, standards and recommended examples, professional publications on brake equipment, tank cars, locomotives, buffer systems, wheels, axles, bearings and vehicle design, M- 1003 AAR quality assurance specification, exchange rules reference, 19 AAR technical standards for manufacturing and repairing railway vehicles and components, and the draft drawn up by AAR Professional Technology and Weaving Association. Title 49 of the Federal Law "Transportation" has two subheadings, A and B. Part A of the title is "Administrative regulations of the Ministry of Communications" and part B is "Other regulations related to transportation". The railway regulations of the Federal Railway Administration are usually issued under the title of 49 "Federal Law 49 Transportation" and Chapter 2-Federal Railway Transportation Department No.200-299, covering the provisions of track laying, passenger service, truck safety, signal safety and its inspection and maintenance. Among them, the technical regulations related to railway power equipment mainly include nine aspects, such as freight car safety standard-CFR 215 and locomotive safety standard -—CFR 229. Safety standards for steam locomotives -—CFR 230, railway safety equipment standards -CFR 23 1, passenger equipment safety standards -CFR 238, truck braking system safety standards -—CFR 232, truck rear reflective equipment safety standards -—CFR 224, anti-collision system safety standards -—CFR 229, CFR 238 and electronically controlled braking safety standards.
FRA ensures railway safety through the following measures (:1) Federal law (CFR, in which transportation is the 49th title); (2) Implementation Manual (including detailed cases explained by CFR); (3) Safety consultation (warning about railway and public transport safety); (4) execution agreement/execution order (legal agreement signed between FRA and railway transportation company on safety issues); (5) Emergency orders (legal orders to correct special safety problems).
The American railway divides the train speed into nine grades: 1 ~ 5 is constant speed, 6 ~ 9 is high speed, 6 is 177 km/h, 7 is 20 1 km/h, 8 is 257km/h, and 9 is 322 km/h. At present, the actual running maximum speed reaches eight grades. The track safety standard of American high-speed railway (CFR 2 13.345 Vehicle Limit Test) is established, which requires the line test to verify the wheel-rail relationship and the influence of acceleration according to the design speed plus 16 km/h, and begins to study the risk assessment system of high-speed trains.
2. American Railway Technical Standards
American railways have no national technical standards, and their technical standards are formulated, promulgated and implemented by corresponding associations and technical institutions. The most famous is the responsibility of the technical Committee issued by AAR, which represents AAR's TTCI management Committee and maintains standards.
(3) The cargo loading rules are divided into gondola loading rules and boxcar loading rules, which stipulate the loading methods and weights of different vehicles and different goods.
AAR rules are updated twice a year. Whether standards or rules are formulated or revised, they are based on test data. For example, bolster and side frame are prone to problems due to casting defects. A A R initiated the research, made M202-2005 and M203-2005 on the basis of a large number of test statistics, and put forward a new basis for judging whether the fatigue test is qualified or not. For example, the fatigue test of the old tank car after repair proves that the crack does not develop and does not transfer, which provides a basis for the formulation of rules.
AAR mainly coordinates safety and transportation issues among members through standards. In addition to standards, there are also agreements between companies, which stipulate the scope of responsibility when the other party fails to operate. For non-member companies, they also sign agreements with member companies to ensure the implementation of AAR standards. A A R does not require all companies engaged in railway transportation to be members, but through the above measures, non-members are also bound by AAR standards. The specific compilation of A A R standards is the responsibility of the professional technical committee organized by the affiliated technical institution (TTCI).