From a modest family-owned operation founded in 1903, the Wichmann firm has expanded continually, and today its plant is said to be one of the most modern in the world. The company's U.S. manufacturing facility is located in Kenner, La. near New Orleans.
During its first 30 years of operation, Wichmann built two-stroke semi-diesel engines, then switched to two-stroke, full-compression ignition engine production around 1935. Since that time, the company has produced several engine models, increasing its size and horsepower range with each model change.
In the late 1960s, Wichmann introduced the AX and AXG series of in-line engines, which were forerunners to the current engine type, the AXA and the AXAG. The AXA engines are coupled directly to the propeller shaft through an integral hydraulic clutch, as these engines have a relatively low speed of 375 rpm. The AXAG engines operate at higher speeds, 475 rpm, and are normally equipped with reduction gears that are available with an infinite number of ratios. The output of the AXA and AXAG models ranges from 1,350 to 4,000 bhp, and engine configurations range from four to 10 cylinders.
All Wichmann engines are of a simple single-acting, two-stroke cycle, liquid-cooled design, and all are turbocharged, intercooled, loop-scavenged, and direct-injected. The scavenging process is timed by inlet and outlet ports in the cylinder liners, so there are no valves or valve-operating mechanisms. All major components are of modular construction. Accessories are driven by gear trains located at both ends of the engine.
This design provides a sturdy, reliable engine that requires a minimum of maintenance and is simple to repair. For example, the removal of four nuts permits removal of a cylinder head. The absence of valves and the valve train eliminates one of the major causes of diesel engine failure.
Overall, experience has shown that the ratio of operating hours to maintenance hours is higher and economical for the operator. Complete interchangeability of parts between engine types and a smaller onboard inventory of spares reduces maintenance support problems and storage requirements, which frees operating capital. With fewer moving parts and low engine speeds, engine wear is said to be reduced substantially, and lube oil lift extended. In other areas of economy, fuel utilization is said to be extremely low — one of the primary application considerations today — and intermediate fuels have always been available in Wichmann systems as a viable alternative to marine diesel oil.
Considerable research, development, testing, and evaluation have resulted in an engine design that provides one of the lowest fuel consumptions in the world, specifically, 0.3417 pounds per bhp hour. This translates into approximately 0.046 gallons per bhp hour. In practice, the Wichmann 4AXA, which is rated at 1,350 bhp, would consume approximately 63 gallons per hour at full load.
It is common practice today, however, to purchase a propulsion system that provides approximately 120 percent of the required load, permitting the system to be operated at 80 percent load. This reduced loading enables the engine to be operated in the optimum portion of the fuel consumption curve.
Functionally, the Wichmann scavenging system, low engine speed, and long stroke provide this increased fuel efficiency, which also results in a more uniform and complete combustion process, utilizing all of the fuel that is injected for the propulsion of power rather than smoke generation. This also minimizes carbon deposits, especially in intermediate fuel applications.
In the near future, a Wichmann V engine will become part of the engine family. The V engine is now in the final stages of test and evaluation. When production models are available, the engine series will provide a power range of from 1,800 to 4,800 bhp, with configurations from six to 16 cylinders.