Gas engines

Rolls-Royce Bergen - the power of experience

Rolls-Royce Bergen engine

Rolls-Royce provides a range of spark ignition (SI) gas engines based on its B- and C- engine platforms in the power range between 1.460 - 9,400 kWe. These engines are well established in the market and are highly competitive in terms of efficiency and emissions.

However, due to market demand for larger engines, we developed the most powerful gas engine that our biggest engine platform, the B32:40, would support, exploiting the best technology from our latest KV-G4 engine version in a way that will create a new and class-leading product for the 720rpm to 750rpm range.


Increased power range

This was achieved by basing the new design on our largest engine platform, the B32:40, extending it to 350 mm, and by making the new engine in versions up to V-20.

Higher efficiency

This means lower gas consumption for the power produced and therefore lower operating costs. Key factors in achieving this are that the B-gas utilises an advanced thermodynamic cycle, has an optimised combustion system, advanced turbochargers with variable turbine geometry, as well as an efficient mechanical design that runs at relatively low speed.

Reduced emissions

Achieved through further developments of the well-known Bergen lean-burn combustion system based on spark ignition in a small pre-chamber, in combination with the advanced thermodynamic cycle mentioned above.

Increased availability

The larger and slower-running B-gas engine has an natural advantage over smaller faster-running engines. However, the high availability is primarily founded in a simple and robust engine design, which has been thoroughly tested and is built to the highest quality standards.

Reduced service cost per kWh

This is due to the simple and robust design of the BV - gas engine, with fewer parts subject to wear, relatively low speed as well as the generous sizing of parts and larger wear margins. Therefore the intervals between overhauls can be longer, giving a lower service cost per produced kWh.

Wide fuel-gas specifications

This remains a factor not to be overlooked, and in being an "Otto cycle" Lean Burn S.I. engine with a fully bore-cooled combustion space, the BV - gas has low anti-knocking requirements compared to alternative gas engine types.

Technical data

Bergen B-Gas engine

Stationary engines - Gas 
Bergen B35:40VAG - 60/50Hz

Principal dimensions 
Cylinder diameter 350 mm. Piston stroke 400 mm

Engine performance
Engine typeABCWeight gen-set
B35:40L9AG110702560453088800 kg
B35:40V12AG105752750462099800 kg
B35:40V16AG1156533064545119500 kg
B35:40V20AG131603306470014800 kg
Technical data
Engine typeB35:40L9AGB35:40V12AGB35:40V16AGB35:40V20AG
Number of cylinders9121620
Engine speed r/min720/750720/750720/750720/750
Electrical output, η = 0.97 kW3685/38404890/50957170/74658960/9330
Mechanical output kW3780/39405040/52507390/77009240/9620
Mean effective pressure (BMEP) bar18.
Specific fuel gas consumption kj/kWh7510743572307320
Fuel gas consumption kW7885/822010405/1084014845/1545518785/19560
Specific lube oil consumption g/kWh0.
Thermal output kW3940/41005100/51357080/73709070/9445
Nom. el efficiency %46.747.048.347.7

The Bergen C25:33 family, launched in 2002, is one of the most compact and powerful 250mm bore diesel engines in the world. It has a track record of very low life cycle costs, is designed for long service intervals and is easy to maintain.

The liner, piston, (incl. upper con rod) and cylinder head can be replaced as a single unit, without disturbing the big end bearing, saving users a lot of time and money. This robust engine design has been further developed to produce the Bergen C26:33 Gas and is now available in powers from 1,425 to 2,370kW.


  • Compact and powerful
  • Exceptionally low emissions of NOx, CO2, SOx and particulates
  • Optimum response at all engine load points (Variable Turbo Geometry)
  • World class low energy consumption
  • Super silent resilient mounting

Technical data

Bergen C-gas engine

Stationary engines - Gas 
Bergen C26:33L AG - 60/50Hz 

Principal dimensions 
Cylinder diameter 260 mm. Piston stroke 330 mm

Engine performance
Engine typeABCWeight gen-set
C26:33L6AG73002080340037000 kg
C26:33L9AG84502080340043000 kg
Technical data
Engine typeC26:33L6AGC26:33L9AG
Number of cylinders69
Engine speed r/min900/1000900/1000
Electrical output, η = 0.96 kW1400/15552100/2335
Mechanical output kW1460/16202190/2430
Mean effective pressure (BMEP) bar18.518.5
Specific fuel gas consumption kj/kWh7560/76657410/7510
Fuel gas consumption kW3060/34454500/5065
Specific lube oil consumption g/kWh0.40.4
Thermal output kW1540/17502220/2530
Nom. el efficiency %45.7/45.146.7/46.1

The Bergen engines are supported worldwide by the Rolls-Royce global service network, and a range of tailored maintenance packages are available, including service exchange modules. Our goal is to keep your power plant profitable and your investment protected.

See the Services section for more information