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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Interpretation Response #09-0136 ([SJ Transportation Co., Inc.] [Mr. Christopher P. Prioli])

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date:

Company Name: SJ Transportation Co., Inc.

Individual Name: Mr. Christopher P. Prioli

Location State: NJ Country: US

View the Interpretation Document

Response text:

January 27, 2010



Mr. Christopher P. Prioli

Safety & Compliance Manager

SJ Transportation Co., Inc.

P.O. Box 169

1176 U.S. Route 40

Woodstown, NJ 08098

Ref. No. 09-0136

Dear Mr. Prioli:

This responds to your letter requesting clarification of the construction and marking requirements for DOT 407/412 variable specification cargo tank motor vehicles (CTMVs) under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). Your questions are paraphrased and answered as follows:

Q1. Under § 178.345-14(c)(6) and (c)(7), the maximum loading and unloading rates in gallons- per- minute ismust to be marked on the specification plate of a DOT 406, 407 and 412 CTMV. The manufacturer of our variable specification DOT 407/412 CTMVs only marks the pressure on the specification plate at which the maximum loading and unloading rate is given as a hyphen that denotes no limit is placed on the flow rate. Is this practice correct?

A1. No. As specified in the introductory text under § 178.345-14(c), the maximum loading and unloading rate in gallons- per- minute entry is required regardless of its applicability or appropriateness.

Q2. Our company"s DOT 412 CTMVs were found to be in violation of the venting and drainage requirements for ring stiffeners that enclose an air space under § 178.345-7(d)(4). What is the appropriate location for ring stiffener drains? Must the vents be visible to verify compliance?.

A2. The HMR do not explicitly dictate the location of vented drains in the enclosed air space of a ring stiffener. It is the opinion of this Office that a ring stiffener drain or vent should be visible, as far as practicable, in order to verify compliance with the HMR. Additionally, there is no need to install multiple vents or drains when only one satisfies the intent and functionality of the requirement.

I trust this satisfies your inquiry. Please contact us if we can be of further assistance.


Hattie L. Mitchell

Chief, Regulatory Review and Reinvention

Office of Hazardous Materials Standards


Regulation Sections

Section Subject
178.345-14 Marking
178.345-7 Circumferential reinforcements