Drives: Which to choose?



Many of MarineDiesel’s engines are sold as vessel performance packages, as a complete unit: Engine, Gearbox, and Drive, ready to install. Of course, you can always purchase an engine from us and install your own equipment, but packaging allows the shipyard to combine installation, commissioning, and after sale service into a package easily service by our trained technicians, often at a far lower cost than buying each component separately (Since we buy far more gearboxes and drives per year than the average shipyard and most of our partners pass warranty expense to us, we can sometimes deliver components at a lower price.)

This brings up the question: What type of propulsion should I use on my vessel?

There is no single answer other than, “It depends on how the vessel will be used.”

Each propulsion method has strengths and weaknesses.

For instance, on single engine installation, surface drives are not a good option due to torsional pull. On these vessels, a stern drive or water jet should be considered.

MarineDiesel has put together packages with all of the major drive types. What should you choose? See below.

Sterndrive: good trim and reverse. Good box size for davit operation. Traditionally not strong but Konrad and MD is. More drag than surface drive. Good steering. Easy to install and small inside build dimension. Cheap propellers. Normally integrated transmission (not Konrad). Trolling function with MD, joystick control, crash stop. Low cost.
Waterjet: Safety aspects, no propeller. Will not work if there is too much debris. Bad efficiency in low and mid range. Crash stop. Very durable. No trim capability. Must in most cases use transmission. Expensive. Good maneuverability.
Surface drive: Highest speed and most durable in most cases. Expensive propellers. Poor slow speed performance. Difficult to handle torque response in single engine installation. Must use transmission. Can be expensive.
Pod system: Easy to install. No trim function. Falls off on impact, expensive to replace. Designed for pleasure use. Good steering and available with joystick. Very expensive.
Shaft setup: Durable. Needs transmission. Medium efficiency. Complex for boat builder to install. Good reverse and medium steering. No trim.