The Bergen B33:45 is a medium-speed four-stroke trunk-piston marine and stationary diesel engine produced at the Bergen Engines plant in Hordvikneset, Norway, with a 330 millimetre cylinder bore and a 450 millimetre piston stroke. The engine is the most recent generation of the Bergen marine engine line, succeeding the long-running B32:40 family. It was introduced commercially around 2017 and has gained significant market share in the cruise, fishing, ferry, and FPSO power-generation segments. Cylinder configurations span six to nine in-line, with rated outputs from approximately 3,200 kilowatts to 6,000 kilowatts. A V configuration variant has been progressively added.
Cylinder data and outputs
The B33:45 in current rating produces 600 kilowatts per cylinder at 720 or 750 revolutions per minute. Available in-line configurations are L6, L7, L8, and L9. The platform achieves brake mean effective pressures of around 27 bar through advanced common-rail injection, two-stage turbocharging on selected ratings, and miller-cycle valve timing. The longer stroke-to-bore ratio (1.36) compared with peer engines in the bore class delivers higher torque per unit displacement and supports operation at lower shaft speeds in geared and direct-drive applications.
Bergen Engines corporate evolution
The Bergen engine line has been through several ownerships in the past three decades. Bergen Diesel was a long-established Norwegian marine engine builder. It was absorbed into Ulstein Bergen, then Rolls-Royce Marine through Rolls-Royce’s 1999 acquisition of Vickers (which had previously absorbed Ulstein). Rolls-Royce attempted to sell Bergen Engines to TMH (Russia’s Transmashholding) in 2021, but the sale was blocked by the Norwegian government on national security grounds. Rolls-Royce subsequently sold Bergen Engines to Langley Holdings in 2021. Langley Holdings continues to operate the Bergen brand independently from its UK base.
Fuel and emissions
The B33:45 operates on heavy fuel oil, marine diesel oil, marine gas oil, low-sulphur fuel oil, and bio-fuels. The B33:45LG dual-fuel variant runs on liquefied natural gas in the lean-burn Otto cycle with diesel pilot injection. IMO Tier II compliance is standard; Tier III compliance requires SCR for the diesel variant or operation in gas mode for the dual-fuel variant. Bergen has announced a hydrogen-ready variant of the B33:45 supporting hydrogen blends and a methanol-ready development path.
Applications
The B33:45 is concentrated in Norwegian and European customer markets and in selected global cruise and FPSO references. Notable application categories include:
- Cruise ship integrated power plants, where the B33:45 has displaced earlier Bergen and competitor engines on several premium operator newbuilds.
- Ro-pax and ferry main propulsion, particularly Norwegian and Mediterranean services, often in dual-fuel LNG configuration.
- Fishing vessels at the upper end of the world’s largest tuna seiners, longliners, and trawlers (a market historically dominated by Bergen engines).
- Offshore supply vessels, anchor handlers, and platform supply vessels.
- FPSO main power generation in Brazilian, North Sea, and West African operations.
- Stationary baseload and peaking power plants in the 6 to 100 megawatt range.
Service network
Bergen Engines supports the B33:45 through dedicated service centres in Norway, the UK, the US, Brazil, and Singapore, complemented by authorised service agents in additional ports. The engine’s parts and service network is significantly smaller than MAN PrimeServ or Wärtsilä Lifecycle, but the closeness to the Norwegian fishing and offshore supply customer base remains a competitive strength.
Comparable engines
The B33:45 competes principally against the Wärtsilä 31, the Wärtsilä 32, the MAN 35/44, and the HiMSEN H35DF. Its principal differentiation is the longer stroke-to-bore ratio yielding high torque density and the dedicated focus on the Norwegian and European specialised vessel market. The Wärtsilä 31 has a slight thermal efficiency advantage; the B33:45 has a slight torque density and brake mean effective pressure advantage at typical ratings.