Interesting article and well-written. When the USAF was testing the facilities at Vandenberg AFB that was to have been the West Coast Space Shuttle Launch and Landing Facility, they towed the External Tank to Vandenberg through the Panama Canal so that it could be mated with the dummy orbiter on the launch pad. The barge trailed a second towline aft of the barge so that, in the event the main tow line parted, the tug could circle back and pick up the second tow line.
I used to go on the tow from New Orleans to KSC and a couple buddies made the 30 day trip to VAFB.