Pioneer Work Class ROVs (CURV-III & 21) – Part 2

Following the famous search and retrieval of the lost hydrogen bomb off Palomares, CURV-I continued its operations with the U.S. Navy, and continued being upgrades by later generations of vehicles designated CURV II, CURV II-B, CURV II-C and finally CURV III. In 1973, CURV-III performed the deepest underwater rescue in history when it rescued two men 1,575 feet (480 m) deep, off the southwest coast of Ireland, who were stranded 76 hours in the submersible Pisces III with just minutes of air remaining.

On Wednesday, August 29th, the aft sphere of the submersible, a smaller watertight sphere where the machinery was, had flooded when the hatch was pulled off during recovery operations near the surface. Suddenly the sub was over a ton heavier and sank like a rock. It hit bottom at 40 miles per hour (65 km per hour). On August 31st CURV-III arrived on the scene, but only dived on September 1st, when it attached a line to the submersible’s aft sphere. The lift was stopped twice during ascent. Once at 350ft, for CURV to be disentangled, and a second time at 100ft, so that divers could attach heavier lift lines. Finally Pisces III was lifted to the surface with its two crew member still alive.

In 1976 the CURV-III was used to survey the wreck of the SS Edmund Fitzgerald in the Great Lakes region. CURV-III was the fourth generation of the US Navy Cable-controlled Undersea Recovery Vehicle. After the Space Shuttle Challenger disaster in 1986, CURV III was transferred to the Navy's Supervisor of Salvage who directed that it be upgraded from 10,000 feet (3,000 m) feet operations to 20,000 feet (6,100 m) using technology developed for the Remote Unmanned Work System (RUWS) and the Advanced Tethered Vehicle (ATV).

The redesign and upgrade, performed by Eastport International, produced what is essentially a new CURV III. CURV III continues to be operated by SUPSAL, as does the SSC Pacific-developed Advanced Unmanned Search System (AUSS). The CURV-21 would become the next generation following CURV-III retirement and was built as its direct replacement. CURV-21 is a 6,400-pound Remotely Operated Vehicle (ROV) that is designed to meet the US Navy's deep ocean salvage requirements down to a maximum depth of 20,000 feet of seawater. This vehicle is loaded with a host of new technologies and was built as a direct replacement for CURV-III but with a smaller overall system footprint. The ORION (A towed side scan-sonar) and the CURV-21 can be combined into a single integrated search & recovery system capable of being deployed on a USNS T-ATF. The system is based on a .680 fiber-optic umbilical cable and a shared handling system that can switch at sea between side-scan sonar and ROV operations. The system is self-contained and fly-away transportable for world wide response on vessels of opportunity. In 2012, CURV 21 completed the recovery of a downed U.S. Air Force F-16 Fighting Falcon, in the North Pacific Ocean near the Kuril Islands. 

Source: The ROV Manual, by Robert D Christ, Robert L. Wernli Sr, Space and Naval Warfare Systems Center San Diego (SPAWAR), the Office of the Director of Ocean Engineering Supervisor of Salvage and Diving (SEA OOC), NAVSEA’s Supervisor of Salvage and Diving (SUPSALV) and BBC News.