Regulations last checked for updates: Nov 25, 2024

Title 49 - Transportation last revised: Nov 18, 2024
§ 299.403 - Trainset structure.

(a) Occupied volume integrity. To demonstrate resistance to loss of occupied volume, the trainsets shall comply with both the compression load requirement in paragraph (b) of this section and the dynamic collision requirements in paragraph (c) of this section.

(b) Compression load requirement. The end compression load shall be applied to the vehicle as defined in JIS E 7105:2006(E) as amended by JIS E 7105:2011(E) (all incorporated by reference, see § 299.17), with an end load magnitude no less than 980 kN (220,300 lbf) without permanent deformation of the occupied volume.

(c) Dynamic collision scenario. In addition to the requirements of paragraph (b) of this section, occupied volume integrity shall also be demonstrated for the trainset through an evaluation of a dynamic collision scenario in which a moving trainset impacts a proxy object under the following conditions:

(1) The initially-moving trainset is made up of the equipment undergoing evaluation at its AW0 ready-to-run weight.

(2) The scenario shall be evaluated on tangent, level track.

(3) The trainset shall have an initial velocity of 32 km/h (20 mph) and shall not be braked.

(4) The proxy object shall have the following characteristics:

(i) The object shall be a solid circular cylinder that weighs 6350 kg (14,000 pounds);

(ii) The object shall have a width of 914 mm (36 inches) and a diameter of 1219 mm (48 inches);

(iii) The axis of the cylinder shall be perpendicular to the direction of trainset motion and parallel to the ground; and

(iv) The center of the object shall be located 762 mm (30 inches) above the top of the underframe.

(5) Two collision configurations shall be evaluated.

(i) The center of the object shall be located 483 mm (19 inches) from the longitudinal centerline of the trainset; and

(ii) The center of the object shall be aligned with the side of the cab car at the point of maximum width.

(6) The model used to demonstrate compliance with the dynamic collision requirements must be validated. Model validation shall be demonstrated and submitted to FRA for review and approval.

(7) As a result of the impact described in paragraphs (c)(5)(i) and (ii) of this section—

(i) One of the following two conditions must be met for the occupied volume:

(A) There shall be no more than 254 mm (10 inches) of longitudinal permanent deformation; or

(B) Global vehicle shortening shall not exceed 1 percent over any 4.6 m (15-feet) length of occupied volume.

(ii) Compliance with each of the following conditions shall also be demonstrated for the cab after the impact:

(A) Each seat provided for an employee regularly assigned to occupy the cab, and any floor-mounted seat in the cab, shall maintain a survival space where there is no intrusion for a minimum of 305 mm (12 inches) from each edge of the seat. Walls or other items originally within this defined space shall not further intrude more than 38 mm (1.5 inches) towards the seat under evaluation.

(B) There shall be a clear exit path for the occupants of the cab;

(C) The vertical height of the cab (floor to ceiling) shall not be reduced by more than 20 percent; and

(D) The operating console shall not have moved closer to the driver's seat by more than 51 mm (2 inches).

(d) Equipment override. (1) Using the dynamic collision scenarios described in paragraph (c) of this section, and with all units in the trainset positioned at their nominal running heights, the anti-climbing performance shall be evaluated for each of the following sets of initial conditions:

(2) For the initial conditions specified in paragraphs (c)(1) through (3) of this section, compliance with the following conditions shall be demonstrated after a dynamic impact:

(i) The relative difference in elevation between the underframes of the connected equipment shall not change by more than 102 mm (4 inches); and

(ii) The tread of any wheel of the trainset shall not rise above the top of rail by more than 102 mm (4 inches).

(e) Roof and side structure integrity. To demonstrate roof and side structure integrity, each passenger car shall comply with the following:

(1) Rollover strength. (i) Each passenger car shall be designed to rest on its side and be uniformly supported at the top and bottom cords of the vehicle side. The allowable stress in the structural members of the occupied volumes for this condition shall be one-half yield or one-half the critical buckling stress, whichever is less. Local yielding to the outer skin of the passenger car is allowed provided that the resulting deformations in no way intrude upon the occupied volume of the car.

(ii) Each passenger car shall also be designed to rest on its roof so that any damage in occupied areas is limited to roof extrusions. Other than roof extrusions, the allowable stress in the structural members of the occupied volumes for this condition shall be one-half yield or one-half the critical buckling stress, whichever is less. Local yielding to the outer skin, including the floor structure, of the car is allowed provided that the resulting deformations in no way intrude upon the occupied volume of the car. Deformation to the roof extrusions is allowed to the extent necessary to permit the vehicle to be supported directly on the top chords of the sides and ends.

(2) Side structure. (i) The sum of the section moduli about a longitudinal axis, taken at the weakest horizontal section between the side sill and roof, of the extrusions on each side of the car located between the inside edge of the doors shall be not less than 3.95 x 105 mm 3 (24.1 in 3).

(ii) The sum of the section moduli about a transverse axis, taken at the weakest horizontal section on each side of the car located between body corners shall be not less than 2.64 x 105 mm 3 (16.1 in 3).

(iii) The minimum section moduli or thicknesses specified in paragraph (f)(2)(i) of this section shall be adjusted in proportion to the ratio of the yield strength of the material used to a value of 172 MPa (25 ksi).

(iv) The combined thickness of the skin of the side structure extrusions shall not be less than 3 mm (0.125 inch) nominal thickness. The thicknesses shall be adjusted in proportion to the ratio of the yield strength of the material used to a value of 172 MPa (25 ksi).

(f) Bogie-to-carbody attachment. (1) The bogie-to-carbody attachment shall utilize the service-proven design as used on the N700.

(2) The bogie shall be securely attached to the carbody and designed to operate without failure under the operating conditions of the railroad, including expected mechanical shocks and vibrations.

source: 85 FR 69731, Nov. 3, 2020, unless otherwise noted.
cite as: 49 CFR 299.403