Electric Hydropack
Hydropack is an engine system designed in the Netherlands to power all the requirements of a workboat. By coupling the engine directly to a hydraulic pump the engine power is converted into hydraulic power which can be used for propulsion but also to power auxiliaries such as cranes, winches, pumps and generators.
Now this flexible power system has been expanded to include an electric motor/generator into the drive system to give even more flexibility.This motor/generator is installed in the drive after the hydraulic pump with suitable clutches. In its basic form the motor/generator is driven by the diesel engine to supply electric power for the vessel but to give more flexibility it is also coupled to its own small hydraulic pump so that the vessel can operate auxiliaries using electric power alone. This hydraulic power from the electrical system can also be used to power the propulsion motor for low speed operations.
One of the attributes of the Hydropack system is that the main diesel engine operates at a constant speed and the engine is tuned to operate at its most fuel efficient level at this speed. By using the latest engine technology, Hydropack claims that their installations can offer not only reduced fuel consumption but also reduced sound and vibration plus low maintenance and longer engine life. There is also the flexibility of allowing the engine to be installed anywhere in the boat. Hydropack engines come in three sizes, from 125 to 680 hp.
The electric motor/generator is a 20 hp unit which would be adequate for the propulsion of many small workboats at low speed but the ability of this unit to operate under battery power alone offers a back up propulsion system. To a certain extent this electric motor can take the place of the Hydropack father and son installation where a boat is fitted with a large and small diesel engine to get better fuel economy when operating at low speeds. With the electric system the low speed operation comes from electric motor instead of a second diesel but as with all the Hydropack systems the emphasis is on flexibility of operation.
By Dag Pike
