---
kind: "section"
citation: "49 C.F.R. § 179.202-13"
title: "49"
number: "179.202-13"
heading: "Retrofit standard requirements (DOT-117R)."
url: "https://uscodex.org/cfr/49/179.202-13"
---

# §179.202-13. Retrofit standard requirements (DOT-117R).

- (a) **Applicability.** Each tank retrofit under these specifications must conform to the general requirements of [§ 179.200](/cfr/49/179.200.md) and the prescriptive standards in § 179.202-13, or the performance standard requirements of [§ 179.202-12](/cfr/49/179.202-12.md).
- (b) **Approval to operate at 286,000 gross rail load (GRL).** A tank car may be loaded to a gross weight on rail of up to 286,000 pounds (129,727 kg) upon approval by the Associate Administrator for Safety, Federal Railroad Administration (FRA). See [§ 179.13](/cfr/49/179.13.md).
- (c) **Thickness of plates.** The wall thickness after forming of the tank shell and heads must be, at a minimum, 7/16 of an inch, and constructed with steel authorized by the HMR at the time of construction.
- (d) **Tank head puncture resistance system.** The DOT-117R specification tank car must have a tank head puncture resistance system in conformance with [§ 179.16(c)](/cfr/49/179.16.md?p=c). The full height head shields must have a minimum thickness of 1/2 inch.
- (e) **Thermal protection system.**
  - (1) The DOT Specification 117R tank car must have a thermal protection system. The thermal protection system must conform to [§ 179.18](/cfr/49/179.18.md) of this part and include a reclosing pressure relief device in accordance with [§ 173.31](/cfr/49/173.31.md) of this subchapter.
  - (2) A non-jacketed tank car modified to the DOT Specification 117R must be equipped with a thermal protection blanket with at least 1/2-inch-thick material that meets [§ 179.18(c)](/cfr/49/179.18.md?p=c) of this part.
- (f) **Jackets.** The entire thermal protection system must be covered with a metal jacket of a thickness not less than 11 gauge A1011 steel or equivalent; and flashed around all openings so as to be weather tight. The exterior surface of a carbon steel tank and the inside surface of a carbon steel jacket must be given a protective coating.
- (g) **Bottom outlets.** If the tank car is equipped with a bottom outlet, the handle must be removed prior to train movement or be designed with protection safety system(s) to prevent unintended actuation during train accident scenarios.
- (h) **Top fittings protection—**
  - (1) **Protective housing.** Except as provided in §§ [179.202-13(h)(2)](#h-2) and [(3)](#h-3) of this paragraph, top fittings on DOT Specification 117R tank cars must be located inside a protective housing not less than 1/2-inch in thickness and constructed of a material having a tensile strength not less than 65 kpsi and must conform to all of the following conditions:
    - (i) The protective housing must have a height exceeding the tallest valve or fitting which requires protection and the height of a valve or fitting within the protective housing must be kept to the minimum size compatible to allow for proper operation.
    - (ii) The protective housing or cover may not reduce the flow capacity of a pressure relief device below the minimum required.
    - (iii) The protective housing must provide a means of drainage with a minimum flow area equivalent to six (6) 1-inch diameter weep holes.
    - (iv) When connected to the nozzle or fitting cover plate, and subject to a horizontal force applied perpendicular to and uniformly over the projected plane of the protective housing, the tensile connection strength of the protective housing must be designed to be—
      - (A) no greater than 70 percent of the nozzle to tank tensile connection strength;
      - (B) no greater than 70 percent of the cover plate to nozzle connection strength; and
      - (C) no less than either 40 percent of the nozzle to tank tensile connection strength or the shear strength of twenty (20) 12-inch bolts.
  - (2) **Pressure relief devices.**
    - (i) The pressure relief device(s) must be located inside the protective housing, unless space does not allow for placement within a housing. If multiple pressure relief devices are installed, no more than one (1) may be located outside of a protective housing.
    - (ii) The height of a pressure relief device located outside of a protective housing in accordance with [paragraph (h)(2)(i)](#h-2-i) of this section may not exceed the tank car jacket by more than 12 inches.
    - (iii) The highest point of a closure of any unused pressure relief device nozzle may not exceed the tank car jacket by more than six (6) inches.
  - (3) **Alternative.** As an alternative to the protective housing requirements in [paragraph (h)(1)](#h-1) of this section, the tank car may be equipped with a system that prevents the release of contents from any top fitting under accident conditions where any top fitting may be sheared off.

## Notes

### Amendments

[80 FR 26749, May 8, 2015, as amended at 81 FR 53957, Aug. 15, 2016; 83 FR 48401, Sept. 25, 2018; 85 FR 83403, Dec. 21, 2020]

### Authority

Authority: 49 U.S.C. 5101-5128; 49 CFR 1.81 and 1.97.

### Source

Source: 29 FR 18995, Dec. 29, 1964, unless otherwise noted. Redesignated at 32 FR 5606, Apr. 5, 1967.

### Amendments

[80 FR 26749, May 8, 2015, as amended at 81 FR 53957, Aug. 15, 2016; 83 FR 48401, Sept. 25, 2018; 85 FR 83403, Dec. 21, 2020]