Marshall Foss, shown here assisting a bulk carrier in San Francisco Bay, is one of two Foss Maritime tugs testing a system for accurately measuring the strain put on towlines during assist jobs. [Courtesy Foss Maritime] For tug masters, it's perhaps the greatest eternal mystery. Exactly how many jobs can a towline handle before it's in danger of breaking? How…

For the tugboat industry, it's one of the most famous towing operations in years. Yet it almost didn't happen--twice. On Dec. 5, McAllister Towing and Transportation Co. successfully delivered the historic USS Intrepid to dry dock in Bayonne, N.J. For the previous 24 years, the World War II-era aircraft carrier had rested at Pier 86 in Manhattan as part of…