When the
sternwheeler Spirit of Sacramento
sank to the bottom of the San Francisco Bay last fall with reported diesel fuel
aboard, SCAA member Global Diving & Salvage, Inc. was called in to salvage the vessel.
Teams
immediately evaluated the site to mitigate environmental hazards, and a dive
team conducted an underwater survey to identify any exterior damage. With no
evidence of damage to the hull, the team determined the best option would be to
lift and refloat the vessel.
The surrounding
environment posed several challenges; the Spirit
of Sacramento sank in an area called False River, known for strong currents
of up to two-and-a-half knots. There’s also a short slack water window in the area, with just 15 to
20 minutes between high and low tide.
When
Global first arrived at the scene, the vessel was completely capsized with its
keel visible above the water, so the team planned to roll it over onto its keel
and lift it. After leaving overnight and returning the next morning however, the
Spirit of Sacramento was sitting on
its side.
“The
current had somehow rolled the vessel over 90 degrees, which vastly changed the
scope of the project,” said Global Salvage Officer Kyle Watson. “That was a bit
of a curveball that came up in the middle of the job. We had to readjust our
plan midstream. It actually made the job easier, but it was still something we
had to adapt to.”
The since
the vessel was only meant to travel on protected waters it was very lightly
built; the crew had to rig the vessel carefully to keep it intact during
lifting. They reinforced the hull to keep it from collapsing, fabricating the
pieces they needed on-site.
Due to
the size of the vessel, Global enlisted a derrick barge to perform the heavy
lifting. The vessel was successfully parbuckled, with no damage and no release
of fuel. Because of a lack of facilities in the area that could handle a vessel
of that size, the Spirit of Sacramento was towed 56 miles to an Army Corps of
Engineers dock in Sausalito. The vessel only had 3 to 4 inches of free board,
so the long tow had to be performed very carefully.
Despite
it being a long and difficult haul through the busy Bay Area, Global delivered
the Spirit of Sacramento to Sausalito
without incident. “There’s definitely a sense of accomplishment,” Watson
continued. “All the planning, the naval architecture, the engineering, and then
the work the divers did – it all came to a head and it
worked. That’s definitely a proud moment.”
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