Exploded view of Ossberger Cross Flow Turbine


Maroon Creek Hydro
Aspen, Colorado

Factory Assembly
Rothsee Hydro, Bavaria

The Original OSSBERGER Turbine

When Civil Engineer Fritz Ossberger set out in the early 1920s to find a reliable and economical power source for industry, workshops and mills, his goal was to remove a major stumbling block to the rapid advancement of industrialization.

With considerable foresight, he made contact with the Australian Genius, A.G.M. Michell, about whose work Ossberger had learned. The two men quickly established a strong working relationship and together developed a water power turbine suitable for use by medium-sized manufacturing firms. The new "Free Stream Turbine" design was granted German Imperial Patent No. 361 593, and the OSSBERGER Turbine was born.

From its initial development in the 1920s to the present day, the OSSBERGER Turbine has been dramatically improved. Special techniques for draft tube utilization, construction and application of bearings and the shape of the subdivided guide vane are all inventions which display the continued technological leadership of the OSSBERGER Turbine. In the 1990s the OSSBERGER Turbine has continued to be improved and is the subject of yet another set of patents. Today the OSSBERGER Turbine is built and utilized worldwide and is available for a variety of applications.


The OSSBERGER Cross-Flow Turbine

The OSSBERGER Cross-Flow Turbine maintains its efficiency over a wide range of flows and is often the most economic solution for run-of-the-river plants on flashy or highly variable streams.

Why pick a turbine which is optimally efficient for only a few days of the year? With its stable efficiencies over a wide flow range, an OSSBERGER Turbine offers enhanced performance even at a small fraction of total load. Total energy production often exceeds that of a comparable Francis Turbine, which is less able to utilize flows in the fractional load range.

Depending on the site conditions, only OSSBERGER allows to choose a turbine with either one or two cells, horizontal or vertical inflow design, whichever facilitates the construction needs to save money and assure a cost-effective installation.

OSSBERGER Turbines have proven their reliability at over 10000 small hydropower stations, in over 100 countries, on all 5 continents. OSSBERGER Turbines operate reliably, efficiently and economically, under different conditions, adapted to the local situation and in an ecologically friendly manner.

Have peace of mind: Many OSSBERGER Turbine installations, even where exposed to harsh environments, have run for 30 years and longer without requiring major repairs or spare parts. At only 0.5% of it's annual sales, the Company's spare parts sales offer impressive evidence of the long-term reliability of the OSSBERGER Turbine.

The OSSBERGER-HSI Kaplan - Turbine

  To view the Kaplan - Turbine Brochure,
     click the pdf icon below

Well-established turbine manufacturers gave up their quest to manufacture Kaplan Turbines with small runner diameters due to the high production costs. Only a recent development in the field of production machinery permitted the manufacture of even smaller-sized Propeller Machines at reasonable costs. Being specialized in small hydro, OSSBERGER realized this opportunity at an early stage. Of major consideration was the availability of full test facilities in place at the factory, which permitted detailed testing and improvements to the design of wicket gates and runner blades as well as the geometry of the turbine housing. Special attention was given to the draft tube design, as it plays an important role in this regard.

The actual design used for the manufacturing process of the turbine represented the third generation in the development history. The first step was to establish a computer-simulated model made by the Hydraulic Machinery Department of the Technical University of Munich.  The experience level gained here could be confirmed in the final testing series. Of foremost intention was an increase of unit discharge by modifying the hydraulics and reaching a relative low ratio of hub versus runner diameter. By optimizing the draft tube design the efficiency level could even be further improved.

Special attention was given to the task of Operators in the small scale hydro field to design a low-maintenance turbine with well proven constructional building blocks similar to the OSSBERGER Cross-Flow Turbine of which more than 9000 units were built. Amongst others, these constructional elements are featured as follows:

  • Maintenance-free bearings for wicket gates and runner blades (no oil or grease)
  • Main bearings isolated from water flow using simple stuffing box seals
  • Hydraulic setting of wicket gates and runner blades externally, including emergency shutdown by dead weights without requiring auxiliary power

The OSSBERGER-HSI Movable Power Station

Ossberger now provides a unique solution to generate electrical power from a movable power source which is completely immersed  in a water stream.

Electricity from a movable power source
The OSSBERGER Turbine Regulator

Even the smallest hydropower station must provide safe operation without an Operator standing by. Regulation of the turbine includes automatic startup, grid connection; guide vane position control and emergency turbine shut-down are carried out by the OSSBERGER Regulator, which is specially programmed for the OSSBERGER Turbine.

  • Isolated or stand-alone operation
  • Grid-parallel operation
  • Water level control
  • Speed or load-demand control

The OSSBERGER Regulator is comprised of the following components:

  • Turbine Control Panel with door mounted operational devices including master switch, control transformer, operating mode selector switch, Programmable Logic Controller, over voltage protection, enunciators, motor protective starter, test terminals for trouble shooting
  • Hydraulic Power Unit comprised of aluminum die-cast casing with motor driven gear pump, pressure accumulator, pressure relief valves, gauges, proportional valves with position feed-back, seat valves and return oil filter
  • Water level sensor with support stand and protective tube - hot galvanized, pressure sensor, terminal box and over voltage protection
  • Tach-generator mounted to turbine shaft for speed registration
  • Turbine guide vane arms with counter weights and rotational angle transmitters for position feed-back
  • Hydraulic cylinders complete with tubing and hardware