Inland waterway tanker produces ‘up to 90% less NOx’

The Duandra was built by Shipyard Trico in the Netherlands, and entered service in 2012. Its propulsion system is intended to provide a significant reduction in emissions. Two standard Volvo Penta D16 MG gensets produce power for on-board electricity, thruster, cargo pumps and two electric propulsion motors, which are part of the propulsion system. The main propulsion engines, two 750bhp D16 MH units coupled, with the electric propulsion motors, to an MMW1700 gearbox, driving the propeller. The propeller can therefore be driven by diesel-electric, diesel direct or combined systems, providing the option to choose the most efficient method of propulsion, as well as providing redundancy, claimed to guarantees an almost complete absence of downtime.

The setup reduces the total installed diesel power onboard the Duandra by about 30% compared to a conventional ship. The savings made were used to invest in the extra electric equipment and in catalytic converters and particulate filters for all four D16 engines onboard. This cuts NOx emissions by some 70% to 90% and particulates are reduced by about 40%.

Using the semi-hybrid configuration, the propulsion and genset engines run at a controllable higher load compared to a standard propulsion installation, meaning that the diesel engines, optimised for efficient operation at high load, return a significantly better specific fuel consumption than the single propulsion engine unit of 1,225bhp, as normally fitted to such ships.

According to Volvo Penta, the semi hybrid concept proves that it is possible to build a ship complying with future emission limits, at the same cost as a conventionally-built ship with existing emission levels. This, says the company, is something that has not been done before.

The propulsion engines, gensets and after-treatment equipment were supplied by the Volvo Penta Marine Commercial Center Terlouw in Rotterdam, which is also contracted to provide full servicing of all the equipment.

Principal particulars – MTS Duandra

Length oa: 110m
Width: 16.2m
Displacement: 6060t
Propulsion: 2 x Volvo Penta D16 MH 552kW/1,900rpm.
Gensets: 2 x Volvo Penta D16 MG, with Stamford HCM 534F-1 generator, 596kVA/60Hz.
Harbour set: 1 x Volvo Penta D5A-B TA with Stamford UCM 274E-1 generator, 108kVA/50Hz