The auxiliary propulsion system APS refers to a propulsion device of a vessel, formed by a hydraulic motor, whose axis directly drives a propeller propeller, provided with positioning means at different heights of draft in relation to the hull of the ship and provided of lateral orientation means.
This device has been designed for the purpose of propelling the ship, and it supplements the operation of the main engine in case of failure of the main propulsion system or during those maneuvers or moments in which the boat does not require a high speed.
In some fishing boats, during the working day and especially in the rest time, spaces of time are produced where the main engine is used at very low speeds, to move the vessel slowly, since speed is not necessary.
Through the use of the APS device we significantly improve the Energy Efficiency of our vessel (reducing energy use but with the same final result).
Working hours influence the expensive maintenance intervals (which can now be extended). For this reason, the quantity of oil, oil filters, gas-oil filters, air, etc. and, in short, spare parts that must be used for the mere fact of having hours of operation, are considerably reduced.
Environmental benefits
Speaking of axhaust emissions, we emphasize that an auxiliary engine works at a constant rate of speed (155/1800 rpm) so that their exhaust emissions are significantly lower than those of a variable rpm engine.
We must also comment that the waste generated by the aforementioned maintenance intervals, ie oils, filters, etc. They are much smaller.
The APS device can also be used in case of failure of the ship´s main propulsion system. What would allow not only to face the conditions of the state of the sea, or depart from possible threats such as stones, merchant ships with a fixed course, etc., but also allow the return to port.
Studying the devices present on board a ship we find that the source of energy that has more possibilities of redundancy is hydraulics.
This is why we have chosen hydraulic energy as the energy source of our device.