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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 #PI-75-036 ([Federal Highway Administration] [E. L. Shaw])

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

Interpretation Response Details

Response Publish Date:

Company Name: Federal Highway Administration

Individual Name: E. L. Shaw

Location State: MS Country: US

View the Interpretation Document

Response text:

July 21, 1975

Mr. E. L. Shaw
Division Engineer
Federal Highway Administration
666 North Street, Suite 105
Jackson, Mississippi 39202

Dear Mr. Shaw:

This responds to your June 17, 1975, memorandum to this office requesting information on
pipeline encasement requirements.

The minimum Federal safety standards for transportation by pipeline are 49 CFR Part 192,
Transportation of Natural and Other Gas by Pipeline, and 49 CFR Part 195, Transportation of
Liquids by Pipeline. Neither of these regulations require that casings by used. However, Section
195.256, Crossing of railroads and highways, of the liquid regulations requires such crossings be
installed so as to adequately withstand the dynamic forces exerted by anticipated traffic loads.

Section 192.103, General, of the gas regulations requires that all pipelines be designed with
sufficient wall thickness, or must be installed with adequate protection to withstand anticipated
external pressures and loads. Section 192.323, Casing, sets forth the requirements for casings if
they are used on a gas transmission line or main under a railroad or highway.

As a result of an explosion in a casing on a natural gas transmission line near Monroe, Louisiana,
on March 2, 1974, the National Transportation Safety Board in Pipeline Accident Report NTSBPAR-75-1 recommended that the Office of Pipeline Safety Operations undertake an industry wide survey of the use of casings on pipelines in cooperation with the Federal Highway Administration,
the American Association of State Highway Transportation Officials and other appropriate
industry associations and engineering societies. As yet this project has not been initiated.

The American Society of Civil Engineers (ASCE) has a study that was published in 1971 titled,"Pipeline Crossings of Railroads and Highways." This is available from ASCE, 345 East 47th Street, New York, New York 10017, at a cost of $3.00.

Thank you for your interest in pipeline safety.



Cesar DeLeon
Acting Director
Office of Pipeline Safety Operations

Regulation Sections

Section Subject
192.323 Casing