Steam Turbine Generator Suppliers

A marine steam turbine generator (STG) converts boiler-raised steam into electrical power across two operational profiles - primary electrical generation on steam-propelled LNG carriers and large naval auxiliaries, and bottoming-cycle generation in waste heat recovery system (WHRS) installations where exhaust gas from a 2-stroke diesel main raises steam for an STG. Marine steam turbine generator suppliers handle equipment-level procurement of the STG package - turbine rotor, alternator, gearbox, condenser, and control system - across both newbuild specification and retrofit replacement work.

STG Roles - LNG Carrier Generation and WHRS Power Recovery

Marine steam turbine generator equipment serves two distinct duty profiles. Primary electrical generation on legacy LNG carriers running steam turbine main propulsion - the same boiler plant that feeds the propulsion turbine also drives a turbo-generator (typically two STGs in parallel) providing the vessel's electrical service at 440 V or 6.6 kV. Power output per STG typically 1,500 kW to 4,500 kW. Waste heat recovery STG installation on newer 2-stroke diesel main vessels - exhaust gas from the slow-speed diesel passes through a heat recovery steam generator (HRSG) raising superheated steam at 8 to 15 bar, which drives a small marine STG (typically 500 kW to 2,500 kW) feeding the ship's electrical bus and reducing the auxiliary diesel generator load. WHRS STG recovery yields 3 to 6 percent of total propulsion energy back as electrical power, with the economic case strongest on long-leg deep-sea trade where the main engine runs steady-state at design power for weeks at a time.

Shinko, Kawasaki, MAN, Wartsila - STG Brand Landscape

The marine STG market is concentrated around several specialised OEMs. Shinko Industries (Japan) holds the largest single share on marine STG installations, with the SST-200, SST-300, SST-400, and SST-600 ranges across 200 kW to 5,000 kW class - fitted on LNG carriers, container ships with WHRS, and large bulk carriers. Kawasaki Heavy Industries covers the K-series marine STG on LNG carrier orders and combined-cycle propulsion. MAN Energy Solutions Power-Pac and MAN TCS-PTG (Power Take-In/Out) cover WHRS turbine generator scope on container ships and bulk carriers. Mitsubishi Heavy Industries holds the MR-series marine STG on its own LNG carrier deliveries. Siemens Energy Industrial Steam Turbine and Dresser-Rand cover smaller marine STG and WHRS installations on certain offshore and commercial applications. ABB Marine and Wartsila Marine cover the integrated WHRS package including the turbine generator scope. Power output per STG ranges from 200 kW on small WHRS retrofits up to 8,000 kW on large legacy LNG carrier installations.

Waste Heat Recovery System Specification

WHRS STG specification at newbuild stage maps to the main engine's exhaust gas conditions. Slow-speed 2-stroke main engines (MAN B&W ME, Wartsila X) generate exhaust gas at 250 to 350 degrees Celsius and high mass flow, which suits HRSG steam-raising at 7 to 15 bar. The HRSG output drives the STG at design speed (typically 6,000 to 12,000 rpm on smaller units, geared down to 1,500 or 1,800 rpm at the alternator shaft). Combined exhaust gas economiser and power turbine architecture - where part of the exhaust gas drives a power turbine directly coupled to a shaft generator and part raises steam for the STG - delivers higher total energy recovery on the largest container ship and bulk carrier WHRS installations. Class society type approval (IACS member or non-IACS) covers the integrated WHRS package including the boiler, turbine, generator, gearbox, and control system. For the parallel diesel electrical generation that the STG supplements or replaces under WHRS operation, marine diesel generator suppliers cover the auxiliary diesel side of the electrical system. For the main propulsion steam turbine on legacy LNG carriers driving the same boiler plant as the STG, marine steam turbine engine suppliers cover the propulsion-side turbine scope.

Class Compliance and Type Approval

Marine steam turbine generator procurement runs under IACS Unified Requirements for electrical machinery (UR E) and steam plant equipment (UR P boilers, UR M machinery), SOLAS Chapter II-1 machinery space requirements, and IEC 60092 electrical installations in ships. IACS member societies (DNV, ABS, Lloyd's Register, Bureau Veritas, RINA, ClassNK, KR, CCS) issue type approval certificates against the framework; non-IACS bodies (HRS, INSB Class, RMRS, Other) cover specific flag administrations. The IGC Code governs LNG carrier STG specifics. Type approval covers the turbine rotor, the alternator (synchronous or induction), the reduction gearbox, the condenser, the control system, and the integrated electrical protection scheme.

Procurement Channels and Lead Times

Marine STG procurement runs through three principal routes. New direct from the OEM (Shinko Industries, Kawasaki Heavy Industries, Mitsubishi Heavy Industries, MAN Energy Solutions, Siemens Energy) ships into newbuild orders on lead times typically 14 to 24 months including factory acceptance test and commissioning. Retrofit WHRS STG installation runs through MAN Energy Solutions, Wartsila, ABB Marine, and specialised WHRS integrators delivering the full HRSG plus turbine generator package. Rotor refurbishment, alternator rewind, blade replacement, and condenser tube renewal runs through OEM service centres and class-approved third-party MRO facilities operating under the relevant OEM authorisation. The reclaimed market on STG units is small because the equipment is highly specific to the boiler steam conditions and vessel electrical system.

Selecting a Marine STG Supplier

When you shortlist marine steam turbine generator procurement partners, weigh the structural evidence on each profile:

• Brand authorisation matched to existing installation - Shinko SST-series, Kawasaki K-series, Mitsubishi MR-series, MAN Power-Pac, Siemens, Dresser-Rand original specification dictates the rotor and parts procurement route.
• Power output, voltage, and frequency match - kW output, 440/690 V, 50/60 Hz, synchronisation capability and Power Management System integration matched to the vessel's electrical architecture.
• WHRS integration scope on retrofit work - HRSG, turbine, generator, gearbox, control system, exhaust gas piping, and bus integration as a documented package.
• Class society type approval coverage - IACS member or non-IACS recognition matched to the vessel's class registry plus IGC Code compliance on LNG carrier specifications.
• Lead time alignment with drydock or newbuild schedule - retrofit STG installation 8 to 14 months from order to commissioning; newbuild lead times 14 to 24 months.

Marine steam turbine generator suppliers worth shortlisting deliver brand-authorised channels, the WHRS integration documentation, the class type approval pack, and the lead-time alignment that lets a steam turbine generator return to service against the next class survey window or commission cleanly into a newbuild electrical system.