Title 49
SECTION 299.409
299.409 Brake system.
§ 299.409 Brake system.(a) General. The railroad shall demonstrate through analysis and testing the maximum safe operating speed for its trainsets that results in no thermal damage to equipment or infrastructure during normal operation of the brake system.
(b) Minimum performance requirement for brake system. Each trainset's brake system, under the worst-case adhesion conditions as defined by the railroad, shall be capable of stopping the trainset from its maximum operating speed within the signal spacing existing on the track over which the trainset is operating.
(c) Urgent brake system. A trainset shall be provided with an urgent brake application feature that produces an irretrievable stop. An urgent brake application shall be available at any time, and shall be initiated by an unintentional parting of the trainset or by the trainset crew from the conductor rooms.
(d) Application/release indication. The brake system shall be designed so that an inspector may determine whether the brake system is functioning properly without being placed in a dangerous position on, under or between the equipment. This determination may be made through automated monitoring system that utilizes sensors to verify that the brakes have been applied and released.
(e) Passenger brake alarm. (1) A means to initiate a passenger brake alarm shall be provided at two locations in each unit of a trainset. The words “Passenger Brake Alarm” shall be legibly stenciled or marked on each device or on an adjacent badge plate.
(2) All passenger brake alarms shall be installed so as to prevent accidental activation.
(3) When a passenger brake alarm is activated, it shall initiate an emergency brake application. The emergency brake application can be overridden by the driver so that the trainset can be stopped at a safe location.
(4) To retrieve the emergency brake application described in paragraph (e)(3) of this section, the driver must activate appropriate controls to issue a command for brake application as specified in the railroad's operating rules.
(f) Degraded brake system performance. The following requirements address degraded brake system performance on the railroad's high-speed trainsets -
(1) Loss of power or failure of regenerative brake shall not result in exceeding the allowable stopping distance as defined by the railroad;
(2) The available friction braking shall be adequate to stop the trainset safely under the operating conditions defined by the railroad;
(3) The operational status of the trainset brake system shall be displayed for the driver in the operating cab; and
(4) Under § 299.607(b)(5), the railroad shall demonstrate through analysis and testing the maximum speed for safely operating its trainsets using only the friction brake system with no thermal damage to equipment or infrastructure. The analysis and testing shall also determine the maximum safe operating speed for various percentages of operative friction brakes.
(g) Main reservoir system. The main reservoirs in a trainset shall be designed and tested to meet the requirements set forth in JIS B 8265:2010(E) (incorporated by reference, see § 299.17). Reservoirs shall be certified based on their size and volume requirements.
(h) Main reservoir tests. Prior to initial installation, each main reservoir shall be subjected to a pneumatic or hydrostatic pressure test based on the maximum working pressure defined in paragraph (g) of this section unless otherwise established by the railroad's mechanical officer. Records of the test date, location, and pressure shall be maintained by the railroad for the life of the equipment. Periodic inspection requirements for main reservoirs shall be defined in the railroad's inspection, testing, and maintenance program required under § 299.445.
(i) Brake gauges. All mechanical gauges and all devices providing electronic indication of air pressure that are used by the driver to aid in the control or braking of a trainset shall be located so that they can be conveniently read from the driver's normal position during operation of the trainset.
(j) Brake application/release. (1) Brake actuators shall be designed to provide brake pad clearance when the brakes are released.
(2) The minimum brake cylinder pressure shall be established to provide adequate adjustment from minimum service to emergency for proper trainset operation.
(k) Leakage. The method of inspection for main reservoir pipe and brake cylinder pipe leakage shall be prescribed in the railroad's inspection, testing, and maintenance program required by § 299.445.
(l) Slide alarm. (1) A trainset shall be equipped with an adhesion control system designed to automatically adjust the braking force on each wheel to prevent sliding during braking.
(2) A wheel slide alarm that is visual or audible, or both, shall alert the driver in the operating cab to wheel-slide conditions on any axle of the trainset.
(3) Operating restrictions for a trainset with wheel slide protection devices that are not functioning as intended shall be defined by the railroad under its requirements for movement of defective equipment required by § 299.447, and within the railroad's operating rules, as appropriate.
(m) Monitoring and diagnostic system. Each trainset shall be equipped with a monitoring and diagnostic system that is designed to assess the functionality of the brake system for the entire trainset automatically. Details of the system operation and the method of communication of brake system functionality prior to the dispatch of the trainset shall be described in detail in the railroad's Operating Rules and inspection, testing, and maintenance program required by § 299.445.
(n) Trainset securement. Each trainset shall be equipped with a means of securing the equipment, independent of the friction brake, on the grade condition defined by the railroad. The railroad's operating rules shall define procedures for trainset securement and the railroad shall demonstrate that these procedures effectively secure the equipment in accordance with § 299.607(b)(5).
(o) Rescue operation; brake system. A trainset's brake system shall be designed so as to allow a rescue vehicle or trainset to control its brakes when the trainset is disabled.