Penn Maritime, of Stamford, Conn., has completed a five-vessel construction program with recent delivery of the 4,000-hp ATB offshore tug Mako, the 15th ATB to join the Penn fleet.

Mako is a 116-foot, 4,000-hp tug with a single, raised pilothouse, Cummins engine power and a JAK coupler system. Upon delivery in late 2010, she was matched with a new 90,000-bbl heated asphalt and petroleum barge, Penn No. 95, built last year by Corn Island Shipyard of Lamar, Ind.

Two of the newest tugs in Penn Maritime’s fleet include Yellowfin (pictured) and Mako. They are part of a five-vessel building program for Fin-class ATBs. (Brian Maniglia photo)

Like others of the same Fin class, the tug Mako was built by Thoma-Sea Boat Builders, of Houma, La., over the past few years. The tug was designed by Frank Basile of Entech & Associates.

She is outfitted with a JAK 400 coupler system with pneumatically operated 16-inch diameter pins using any of eight sockets on each wing of the barge skeg for receptacles.

All of the Fin-class tugs are powered by QSK-60 Cummins V-16 main engines producing up to 2,000 hp each at 1,800 rpm and connected to Reintjes marine gears and 104-inch propellers in NautiCan nozzles with shutter rudders.

Auxiliary power comes from 99-kW John Deere auxiliary power generators.

Other Penn tugs in the Fin class are Skipjack, Coho, Yellowfin and Bluefin, all constructed by Thoma-Sea and matched with barges built by Corn Island Shipyard. Skipjack, first in the series, was completed and matched with her barge in 2008.

Mako‘s design provides her crew with 51-foot height of eye from the aluminum wheelhouse tower. Included in equipment are redundant controls, gauges and navigation displays with EMI controls, RexRoth steering and Furuno electronics.

A key part of her deck equipment is the two-speed capstan provided by JonRie InterTech and complete emergency towing gear to be used with the capstan and H-bitts. Designed to always be pushing their barges, none of the Fin class tugs are outfitted with towing winches.

Five new barges were introduced along with the five Fin-class tugs. These are 414 feet in length with capacity of 110,000 barrels, each with two 10 million BTU hot oil heaters and pumping capability of 5,000 barrels per hour.

Penn Maritime, based in the New York area, describes itself as the largest U.S. transporter of heated asphalt products. The company was one of the early pioneers in the use of articulated connection systems between tugs and oil barges.