GE hybrid electric propulsion systems have been selected to power the Italian Navy’s new Pattugliatori Polivalenti d’Altura (PPA) multipurpose offshore patrol ships. Featuring the company’s LM2500+G4 gas turbines, the system will also incorporate GE’s shock-proof MV3000 electrical power converter drives to control the network of propulsion motors.
The PPA ships will be built by Fincantieri at its Integrated Shipyard of Riva Trigoso and Muggiano. Avio Aero, a GE Aviation business headquartered in Italy, will carry the design responsibility for the gas turbine propulsion packages. Fincantieri’s announcement on the project indicated that the PPA patrol ships would be multi-functional, serving on sea patrol and rescue duties and in civil protection operations. With first deliveries scheduled for 2020, the vessels will be 133m long and typically carry 90 crew-members.
“We are excited to be part of a project that will continue to modernise and strengthen the Italian Navy’s surface fleet,” said Tim Schweikert, president and chief executive of GE Marine Solutions. “Our contract includes an order for seven LM2500+G4 gas turbines. The ship’s flexible and unique hybrid propulsion plant will feature small gearbox mounted-motors for low-speed operations, two propulsion diesels for mid-speed service and the gas turbine to reach more than 32 knots. We will also be responsible for the electrical system integration of the hybrid system”
The diesel engines each drive through individual gearboxes to port and starboard propeller lines and are also linked to the centrally located gas turbine and main drive gearbox. The system gives maximum flexibility in use of the power equipment and also maximises redundancy, so that ship propulsion and power can be maintained even if the power plants or sections of the system suffer failure or damage. The MV3000 converter is used to feed the electric motors to rotate the propellers for low speed operation and the hybrid motor and drive also operates as the generator to power equipment onboard the vessel, including weapons and sensors. A further feature is the system’s ability to deliver up to 2MW of electrical power to the shore, should this be needed for assistance to disaster recovery operations or for shore power support. The converter drives are able to deliver power at either 50 or 60 hertz, allowing compatibility with shore frequencies whatever the location.
GE has also received a boost for its potential business in China with GE Marine and the Dalian Shipbuilding Industry Company, Ltd (DSIC) having received Approval in Principle (AiP) from Lloyd’s Register for a gas turbine-powered LNG carrier design. China is an important player in the shipbuilding market and its recent expansion in LNG carrier production has been rapid.
Current oil price levels and the downturn in the marine industry has meant that China’s shipbuilders have come under increasing cost pressure in both CAPEX and ship operation. The gas turbine systems have lighter weights and smaller footprints than low-speed diesel engines and the new compact LNG carrier design allows room for more cargo with approximately 4,000m3 of additional space being available within the same size hull. The power plants will also have the ability to run on either LNG or liquid fuel.
Having secured the Lloyd’s AiP, GE Marine and DSIC believe that customers will feel highly confident about investing in gas turbine-powered LNG carriers and that the product will help China’s shipyards to remain in a competitive position for production of these vessels. The innovative design has a carriage capacity of 179,400m3 and power will be provided by a GE COGES system based around a 25MW aero derivative marine gas turbine.