The LM2500+ marine gas turbine is based on the industry standard-setting LM2500. Its main features are increased power (20%), the same high availability and reliability and an even higher efficiency (lower sfc) than the LM2500.
The primary difference between the two engines is the addition of one stage of compressor blades (stage 0) forward of the LM2500's first stage blading which results in an approximate 20% increase in airflow at full power. The "zero" stage is a wide chord single-piece bladed disk or blisk. The LM2500+'s stage one blades have been redesigned without mid-span dampers. The LM2500+'s 19-stage compressor has an increased pressure ratio to 23.1:1 from 18:1 of the LM2500.
Aft of the LM2500+'s compressor is the fully annular combustor with externally mounted fuel nozzles: a two-stage, air cooled, high-pressure turbine which drives the compressor and the auxiliary drive gearbox; and a six-stage aerodynamically coupled low-pressure power turbine which is driven by the gas generator's high-energy exhaust gas flow. This power turbine was redesigned to strengthen it and allow it to accommodate the higher airflow while maintaining its high level of efficiency.
The LM2500+ marine gas turbine can be housed in a Highly shock-resistant, thermal , acoustic enclosure on a mounting base. The enclosure attenuates noise in the engine room and provides sensors for inlet icing and fire detection. It also houses fire extinguishing equipment. GE furnished modules to the US Navy for the LHD 8.
The simple modular design of the LM2500+ incorporates many features to maximize shipboard maintainability and parts replacement downtime, such as a split compressor casing, in-place blade and vane replacement, in-place hot section maintenance and accessible external fuel nozzles.