Combined gas and gas

A gearbox and clutches allow either of the turbines to drive the shaft or both of them combined.

Marine usage of COGAG systems are similar to those found ashore.

These are each attached to a coupling with both connected to larger gearbox and then to the ship's propeller.

[2] Advantages of the system include a large degree of automation along with quick startup time, they are easier to silence and protect from shock.

[3] Compared to combined diesel and gas (CODAG) or combined diesel or gas (CODOG), COGAG systems have a smaller footprint but a much lower fuel efficiency at cruise speed and for CODAG systems it is also somewhat lower for high speed dashes.