AUS recently completed the change out of 32 2-3/8-inch diameter cables for the I-90 floating bridge, owned and operated by the Washington Department of Transportation. AUS set up a mixed gas, surface supplied diving station, and a modular crane barge anchored on Lake Washington. Most dives were over 200 feet of water, the deepest occurring at 235 feet. Divers breathed a mixture of 84% helium and 16% oxygen (heliox). Dives were often performed in near zero to zero visibility. Divers removed the keeper pins, pressed out the cable pin, installed a newly socketed speltor socket with a new pin. Over 196 dives were performed with zero loss time accidents. In addition to diving, AUS provided 24-hour ROV service and also performed pre and post cable inspections with the ROV. The cables were inspected by professional structural engineers licensed in Washington State. Additionally, AUS performed multi beam and single beam sonar profiles to locate buried anchors and identify sections of the original sunken bridge.
