Jensen Maritime, Crowley Maritime Corp.’s Seattle-based
naval architecture and marine engineering firm, said Dec. 2 that it is
providing designs for two new Azimuthing Stern Drive, 5,360 horsepower tugboats
for New Orleans-based Crescent Towing.
The designs are based on Jensen’s existing 92-foot ASD tug
design. The tugs are the fourth and fifth vessels Jensen has designed for
Crescent, with the most recent design having been delivered in 2010.
“The high horsepower and compact, deep-draft design of the
2010 tug allows us to better serve a wide variety of our customer’s current and
future needs,” Keith Kettenring, Crescent Towing’s executive vice president,
said in a statement.
Improvements made in the new designs are expected to yield
more horsepower and increased stability during the tugs’ operation. Also, a
modified staple placement is expected to increase steering forces by about 30
percent. To accommodate this increase, the tow point is being lowered and
allowed to move further off center, increasing stability in working modes.
Increased brake tension on the bow winch will also
accommodate the increased steering forces, according to Jensen, while tankage
is divided in the new design to better control liquids on board, which could
also improve stability and trim control.
“Horsepower is important for safety due to the increasing
size, tonnage and draft of the ships calling on our ports now and in the
future,” Kettenring explained. “Horsepower is needed to better control these
ships to avoid accidents and environmental casualties.”
For this project, Jensen provided Crescent Towing all the
structural assembly drawings and construction blueprints to aid the process of
cutting and laying out steel pieces to minimize waste during construction.
The 70 metric ton bollard pull tugs will be built by Steiner
Shipyard in Bayou La Batre, Alabama and are scheduled for delivery in November
2015 and January 2016.
