Heavy-Duty & Frame Gas Turbines

A heavy-duty gas turbine — commonly a frame turbine — is a large, robust, single-shaft machine built to run continuously at utility scale. Where an aeroderivative borrows a lightweight jet-engine core, a heavy-frame turbine is a purpose-built industrial machine: heavier rotors, larger casings, and a design optimized for efficiency and endurance over deploy speed.

That design intent shows up in how they are used:

• Baseload generation — running near-continuously as the backbone of a power plant.
• Combined cycle — the turbine's hot exhaust drives a steam bottoming cycle, lifting whole-plant efficiency well above simple cycle.
• Grid-scale output — a single frame machine spans roughly 26 MW to nearly 600 MW, far above the ~70 MW aeroderivative ceiling.

The trade-off is speed and lead time: frames start and load more slowly than aeroderivatives, and new-build order books for the largest classes are booked years out — which is why surplus, used, and refurbished frame units are an active part of the market.

Heavy-frame turbines are grouped by firing temperature and generation, which set their efficiency and their fuel flexibility:

• E-class — the mature, workhorse generation. Lower firing temperature means slightly lower efficiency but exceptional robustness and broad fuel tolerance. Examples: GE Frame 5/6B, GE 9E, Siemens SGT5-2000E, Westinghouse 501D5, Mitsubishi H-25.
• F-class — higher firing temperature for higher efficiency, the mainstream choice for modern combined-cycle plants. Examples: GE 6FA, Siemens SGT5-4000F, Siemens SGT6-5000F, Ansaldo AE94.3A.
• HL-class — the advanced frontier, pushing combined-cycle plant efficiency toward and past 60%. Example: Siemens SGT5-9000HL.

As a rule, higher class means higher efficiency but a newer, tighter supply and a more demanding maintenance regime. E-class units remain widely deployed precisely because they are proven, fuel-flexible, and available.

The heavy-frame units available through Pantheon are below, flagship first, spanning E-, F-, and HL-class. Per-unit output and fuel flexibility are shown on each tile; exact rating, class, and configuration are confirmed at quote. The GE Frame line and Siemens SGT5/SGT6 frames anchor the range, alongside the Ansaldo AE94.3A, Mitsubishi H-25, and Westinghouse 501D5. Each links to its full specification.

Heavy-frame output in this catalog runs from about 26 MW (GE Frame 5PA) to nearly 600 MW (Siemens SGT5-9000HL) in simple cycle. The defining efficiency lever is combined cycle: the turbine's exhaust heat raises steam that drives a second, steam turbine, so a modern F- or HL-class plant reaches net plant efficiencies in the high-50s to low-60s percent — materially above any simple-cycle machine.

That is the core reason to choose a heavy frame over an aeroderivative when time allows: at baseload, the fuel-efficiency gain of a combined-cycle frame plant compounds over years of running. Where speed to power is the binding constraint, aeroderivatives bridge the gap; where efficiency at scale wins, the heavy frame is the machine. Many buildouts use both.

Heavy-frame units are quoted per configuration on request — the figure depends on the model and class, condition (new-surplus, used, or refurbished), fuel system, balance-of-plant, and whether the unit is destined for simple- or combined-cycle service, all confirmed at quote. Tell us the output band, class, and timeline you are planning around and we will return availability and a facility-fit review.

Browse the full gas turbines catalog to compare models, see why gas turbines are effectively sold out for the new-build backdrop that makes surplus frames attractive, or compare with the fast-start aeroderivative class and mid-size industrial class.

Figures on this page are representative public manufacturer specifications for the heavy-duty class and the models shown — not a specification of any specific unit. Actual output, efficiency, condition, and configuration vary by unit and are confirmed at quote; nothing here is an offer, a price, or a warranty.