Indiana Public Service Commission — Pipeline Safety Interpretation

Page 1PI-71-0111 June 9, 1971 Mr. D. J. Hendrickson Chief, Pipeline Safety Division Indiana Public Service Commission 901 State Office Building Indianapolis, Indiana 46204 Dear Mr. Hendrickson: This is in reply to your letter of May 19, 1971, concerning the distinction between the use of the phrase "external loads" in 49 CPR, Section 192.361(a) and Section 192.327(c) and the use of the phrase "external forces" in Section 192.327(d)(3). The distinction is meaningful and was purposely used. Sections 192.361(a) and 192.327(c) refer to transmission line construction and installation of service lines respectively and are concerned with Static loads or traffic impact. Section 192.327(d) (3) is an exception for a situation where less than the required cover may be used. The intent here was to require adequate protection against third party induced damage caused by construction or excavation etc. , We hope this answers your question. Sincerely, Original signed by Joseph C. Caldwell Acting Director Office of Pipeline Safety#

Page 2State of Indiana Public Service Commission 901 State Office Building Indianapolis, 46204 May 19, 1971 Mr. Walter Kurylo States Program Director Office of Pipeline Safety Department of Transportation Washington, D. C. 20590 Dear Mr. Kurylo: Here is one in semantics to which it might be well to give some thought: Section 192.361-(a) states: "--- where an underground structure prevents installation at those depths, the service line must be able to withstand any anticipated external load". Section 192.327-(c) states: "--- main may be installed with less cover if it is provided with addition protection to withstand anticipated external load". In both of these cases the words "external load" implies superimposed loads, such as traffic, which I believe was the intent. However, in Section 192.327-(d)-(3) it states: 'Provides adequately for prevention of damage to the pipe by external forces". By "external forces" one implies any and all external forces such as excavating by others and not just superimposed loads. Should not Section 192.327-(d)-(3) read "external loads" also? Very truly yours, D. J. Hendrickson Chief, Pipeline Safety Division#