Seastreak cat gets c.p. propellers instead of jets

AUGUST 29, 2012 — Midship Marine, Harvey, La., has completed a successful refit of the 43 m Incat Crowther design catamaran ferry Seastreak Wall Street.

Owned by Seastreak LLC, Atlantic Highlands, N.J., the vessel was launched in 2003 and is the third of four sister vessels built by Gladding-Hearn Shipbuilding, Somerset, Mass.

Incat Crowther says the original propulsion package was chosen with emphasis on speed for the Atlantic Highlands to Manhattan service, delivering speeds in excess of 38 knots and four-engine redundancy, with the four Cummins KTA50 main engines, each producing 1424 kW powering four KaMeWa A50 water jets.

Over time, the operating costs of the four-engine drivetrain, changes to the vessels’ schedules and the age of the main machinery led the operator to request an investigation by Incat Crowther into repowering options.

A thorough review led to the selection of a pair of MTU 16V4000M53 engines. Taking into account the operating profile of the vessel, it was deemed that in this case Servogear controllable pitch propellers would offer a significant fuel saving at the vessel’s 32 knot operating speed.

Incat Crowther provided a comprehensive design service, preparing detailed drawings and documentation including revised Coast Guard submissions. Following a competitive tender process, the contract to perform the modification was awarded to Midship Marine of Louisiana.

The engine repower involved a considerable re configuration of the aft end of the vessel. The topsides and the undersides of the hulls were removed from the waterline down, from the forward engine room bulkhead aft. New engine beds, longitudinal stiffeners and plating were fabricated to support the new engines, propellers and rudders.

The refit also included gutting the interior, repainting the vessel and fitting the interior with new carpet and toilets. The framed windows were also replaced with direct-glazing.

After the all the changes, Sea Streak Wall Street is now 15 tonnes lighter than originally built. She recently underwent sea trials, recording speeds of 35 knots. At equivalent deadweights, this represents a reduction in top speed of only 3 knots, despite a significant reduction in power and half the number of main propulsion engines. Combined with an increased in passenger capacity, the refit will see per-passenger CO2 emissions halved.