Marine Gearbox Applications

Kumera has a long and succesfull history in the marine gearboxes business. Our main products have been the Controllable Pitch Propeller (CPP) gearboxes, where a hydraulic actuator built into the gearbox will control the pitch of the propeller through a push rod, positioned inside the propeller shaft.

Also the hybrid propulsion solutions are a major part of the current business. For such systems, the propulsion gearbox has two input/drive shafts, allowing the combination of different power sources, such as diesel engines, electric motors and gas engines to propel the vessel. The two power sources can be used individually, or in combination (boost), resulting in a number of different propulsion modes. Combining such gearboxes with e.g. batteries, environmentally friendly, low fuel consumption solutions can be found.

A propulsion gearbox is traditionally positioned aft of a diesel engine, reducing the rpm of the engine, typically with a ratio of 2:1 to 6:1, i.e. reducing the rpm of the propeller to half to 1/6 of the diesel engine rpm.

Kumera also develops and manufactures customized gearboxes, both for traditional propellers, azimuth drives, bow thrusters, and other special configurations. 

Kumera Hybrid Gearbox

With a hybrid gearbox, two in-shafts will be available, e.g. two different power sources will drive the intended application, either separately, or simultaneously.

Most Kumera hybrid gearboxes are utilized for hybrid vessel propulsion, representing a key enabler when configuring a hybrid propulsion line. The most advanced solution delivered so far was for the vessel BB Power:

A typical hybrid application today is utilizing one diesel engine, and one electric motor, often including a battery pack. The electric motor can also be of a type which can be used as a generator, allowing the battery package to be charged underway.

Using batteries, the vessel can have a pure electrical mode, resulting in no emissions, in turn creating a more pleasant work environment on deck, at the same time protecting the environment.

However, for a hybrid gearbox, all types of power sources can be used, i.e. diesel, electric, LNG, etc., and they can also be the same type of power sources. For instance, for the BB Power tug shown above, a combination of two diesel engines were used for each gearbox, in a father-and-son configuration. 

Kumera Auxiliary System Drives (Front-End Gearboxes)

Front-end gearboxes are, as opposed to propulsion gearboxes, positioned in front of the main engine, connected to the engine’s Power-Take-Off (PTO).

The typical application for Kumera’s front-end gearboxes is driving auxiliary vessel systems like firefighting pumps (FiFi), hydraulic pumps, generators, compressors, etc.

Kumera has a large range of standardized front-end gearboxes, with multiple Power-Take-Off (PTO) and Power-Take-In (PTI) capability, allowing the gearboxes to drive 1-8 different auxiliary systems.

Using a Kumera front-end gearbox will allow running several auxiliary systems in a very reliable, cost-effective way, with a compact installation of the equipment. 

Kumera Fire Pump Gearboxes

Kumera is a well-known manufacturer of fire pump gearboxes for offshore installations. The pump itself is typically positioned 30-50 meters down from the platform deck, below the sea surface.

Traditionally the Kumera bevel gearboxes are used for this application. They are designed with a hollow output shaft in order to connect the water pump drive shaft effectively to the gearbox.

Kumera Bow Thruster Gearboxes

Kumera manufactures the right angle gearboxes to drive bow thrusters for different vessel types.

The Kumera bow thruster gearboxes used for this application represent a robust and cost-efficient design. The application is widely used in marine vessels. 

Sales, Service and Maintenance

We at Kumera are happy to serve customers world-wide. Kindly do not hesitate to contact us in any gearbox related issues.


  • High efficiency – Minimizing power loss and saving energy
  • Modular structure – The ability of adding additional equipment and variety of mounting arrangements
  • Several gearbox sizes and wide range of ratios – Guarantees optimal gearbox size
  • Flexible product structure – Easy to customize for the customer needs 

After Sales Services

  • Start-up and installation services
  • Maintenance services
  • Regular inspection visits
  • Maintenance consulting services 

Marine Gearboxes, Propellers & Propulsions and Applications