Accession Number:

ADA073431

Title:

Corrosion Control of Hardened Intersite Cable System (HICS) Splice Case.

Descriptive Note:

Final rept. Nov 75-Mar 79,

Corporate Author:

AIR FORCE ENGINEERING AND SERVICES CENTER TYNDALL AFB FL ENGINEERING AND SERVICES LAB

Personal Author(s):

Report Date:

1979-05-01

Pagination or Media Count:

46.0

Abstract:

Several thousand splice cases are in use on the hardened intersite cable system between the Strategic Air Commands Minuteman silos. These splice cases are exposed to severe galvanic corrosion caused by interconnection with the graphite impregnated, polyethylene cable sheath which acts as a large cathode. The Air Force Civil Engineering Center conducted laboratory and field tests to determine the magnitude of corrosion for the three different splice cases in use and to develop the surface potential criteria necessary to achieve adequate cathodic protection CP. Test results showed that aluminum splice cases fail quicker than cast iron, and that bronze splice cases with bronze connecting hardware experience little corrosion. The interconnection of dissimilar metals graphite and splice case resulted in the surface potential criteria being significantly different from the standard CP criteria of either a -.85 volt surface potential or a negative 300 millivolt shift. The revised criteria for an aluminum splice case called for a surface potential of -.55 volt or a negative 409 millivolt shift, whereas the cast iron splice case required a surface potential of -.34 volt or a negative 510 millivolt shift. The revised surface potential criteria and the procedure developed to determine the degree of corrosion can be used on any underground metallic system with dissimilar metals. Author

Subject Categories:

  • Electrical and Electronic Equipment
  • Fabrication Metallurgy
  • Containers and Packaging
  • Guided Missile Launching and Basing Support

Distribution Statement:

APPROVED FOR PUBLIC RELEASE