On back: "SAN FRANCISCO-OAKLAND BAY BRIDGE; Walter G. Swanson; 500 Sansome St. - GA rfield 1415. File 900.11 B-12/AA. CABLE SQUEEZER - After the 17,464 wires that make up one suspension cable of the San Francisco-Oakland Bay Bridge have been spun, a portable model of the machine seen in this picture will be slipped along the loosely laid wires. The chain drive will bring six 75-ton jacks to bear on the cable from all sides, compacting it into a circular, tightly squeezed rope only 28-3/4 inches in diameter. Chief Engineer C. H. Purcell expects this operation to start by the end of 1935. This compacting machine will travel the full length of the cable, squeezing as it goes. After it is compacted, the cable will be treated with red lead paste and wrapped spirally."
