Part of the hydrotesting procedure includes sending cylinder-shaped “pigs” through the pipe to perform a variety of functions such as cleaning, removing moisture, gauging for dents or ice accumulations, and for filling the pipe with water during the test. [PC3101-15, # on slide], 1977-04, PCA0002-4b-21, Folder: PCA0002-4b. Alyeska Pipeline Service Company : Trans-Alaska Pipeline Construction Collection, 1976-1977, PCA 2. Alaska State Library - Historical Collections Finding Aids. https://alaska.libraryhost.com/repositories/2/archival_objects/17813 Accessed February 22, 2025.