Bisso returns for new EPA Tier 4 tractor tug

This tug will be similar to 2019-built Andrew S, which was the first tugboat of this type to operate in the river system with propulsion compliant with US Environmental Protection Agency’s Tier 4 emission requirements.

It will be built in Houma, Louisiana, with 4,480 kW of total propulsion power and bollard pull of around 78 tonnes from twin Caterpillar 3516E Tier 4F main propulsion engines, each generating 2,240 kW at 1,800 rpm, driving two Schottel SRP 460 fixed-pitched, azimuthing thrusters with 250 cm diameter stainless steel propellers in stainless steel nozzles.

Also in the engineroom will be Caterpillar C4.4 118 kW generator sets. On deck there will be a JonRie Series 240 escort winch for assisting ships into terminals in Louisiana.

Construction is due to begin in August 2020 with delivery expected in Q4 2021. This will then increase the number of tugs in the Bisso Towboat fleet to 14.

Bisso Towboat said Andrew S was “the most powerful ASD tractor tug in the Mississippi River ship-assist trade” after it was delivered in Q4 2019. It operates eight other ASD tractor tugs on the Mississippi River.

Andrew S has two Caterpillar 3516E Tier 4F main engines, driving two Kongsberg US255 fixed-pitch Z drives. This 30.5 m tugboat has two 99 kW Marathon generators powered by two John Deere 4045AFM85 engines.