---
kind: "section"
citation: "49 C.F.R. § 179.22"
title: "49"
number: "179.22"
heading: "Marking."
url: "https://uscodex.org/cfr/49/179.22"
---

# §179.22. Marking.


In addition to any other marking requirement in this subchapter, the following marking requirements apply:

- (a) Each tank car must be marked according to the requirements in appendix C of the AAR Specifications for Tank Cars (IBR, see [§ 171.7](/cfr/49/171.7.md) of this subchapter).
- (b) Each tank car that requires a tank-head puncture-resistance system must have the letter “S” substituted for the letter “A” in the specification marking.
- (c) Each tank car that requires a tank-head puncture-resistance system, a thermal protection system, and a metal jacket must have the letter “J” substituted for the letter “A” or “S” in the specification marking.
- (d) Each tank car that requires a tank-head puncture-resistance system, a thermal protection system, and no metal jacket must have the letter “T” substituted for the letter “A” or “S” in the specification marking.
- (e) Each tank car manufactured after March 16, 2009, and before December 28, 2020, to meet the requirements of §§ [173.244(a)(2)](/cfr/49/173.244.md?p=a-2) or [(3)](/cfr/49/173.244.md?p=a-3) or [173.314(c)](/cfr/49/173.314.md?p=c) or [(d)](/cfr/49/173.314.md?p=d) that is marked with the letter “I” in the specification marking, following the test pressure, shall be re-marked with the letter “W” with a delimeter of letter “H” at the tank car's next qualification. (Example: DOT 105J600I would be re-marked as 105H600W.) Each new tank car manufactured after December 28, 2020 shall be marked with the letter “W” following the test pressure and with a delimiter of “H”. (Example: 105H600W).

## Notes

### Amendments

[Amdt. 179-50, 60 FR 49077, Sept. 21, 1995, as amended by Amdt. 179-50, 61 FR 33256, June 26, 1996; 68 FR 75759, Dec. 31, 2003; 74 FR 1802, Jan. 13, 2009; 85 FR 75716, Nov. 25, 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

[Amdt. 179-50, 60 FR 49077, Sept. 21, 1995, as amended by Amdt. 179-50, 61 FR 33256, June 26, 1996; 68 FR 75759, Dec. 31, 2003; 74 FR 1802, Jan. 13, 2009; 85 FR 75716, Nov. 25, 2020]