The ALA pelagic doors are MAPSA's most recent commitment, aimed at reducing fuel consumption and emissions of pollutant gases from the engine in trawling, while favoring the treatment of the seabed as there is no physical contact between this and the doors, during towing.
This advantage, common to all pelagic doors, is clouded by the negative impact of the chains that, like mallets, rub against the bottom.
The main concept that was taken into account in the creation of these doors was a series of bet to improve energy efficiency, adopting an advanced hydrodynamic design, composed of an effective wing profile with a high aspect ratio, which incorporates the most recent discoveries in fluid dynamics, which gives it a great opening capacity with minimal hydrodynamic resistance, improved by the absence of friction on the bottom when working suspended on it.
The control of the height of the doors on the bed is achieved with the help of the corresponding sensors, which at all times transmit this information to the ship, together with the separation between them and their possible list.
The improvements provided at the energy level by the ALA SP, can be substantially increased, affecting the design of the art, in order to reduce its resistance to drag. We recall that in most cases said trailer brake represents an average of between 60 and 70% of the total resistance of the fishing gear. Accordingly, the changes to be introduced in the gear should be aimed at reducing the effort required for dragging them, so as to allow better drainage or filtering of the incoming flow through the gear mouth, by increasing the size of the gear. mesh, the reduction of the diameter of the wire of the same, and even, decreasing the angle of the cone that makes up the network.