How does a split shaft differ from a single shaft?

A split shaft configuration in gas turbine systems involves a separation between the high-pressure turbine (HPT) and the power turbine (PT), which results in no direct mechanical connection between the two. This design allows each turbine to operate at its optimal RPM for different applications. The absence of a mechanical linkage enables the power turbine to be driven more independently, giving it greater flexibility in power output compared to a single shaft system, where the turbines are directly connected and must operate together.

In applications where varying operational characteristics are required, such as in marine propulsion or in certain power generation scenarios, the ability to decouple the turbines means that the system can be more versatile. This allows for different load conditions or operational efficiencies that would not be possible in a single shaft setup. The distinct functionality provided by the split shaft architecture significantly enhances performance and adaptability in various operational environments.