Abstract: A watercraft for reduces aquatic plant infestation by mulching or otherwise chopping plants growing on the surface of the water as the craft moves forward along a waterway. Specifically exemplified is an airboat having a hull with an intake port at the bow end of the craft whereby aquatic plant laden water enters the craft; an exhaust port whereby water and mulched aquatic plants are discharged; at least two vertically-oriented spindles having blades attached thereon, and at least one positionable and interchangeable blade assembly disposed in front of the intake port which may be raised, lowered and tilted as desired.

Abstract: The water craft of this invention is capable of efficiently reducing the level of aquatic plant infestation of waterways by mulching or otherwise finely chopping plants growing on the surface of the waterway as the water craft moves through the water. Preferably, the water craft is capable of rapidly moving through plant infested waters while rapidly mulching the infesting plants. In one embodiment, the water craft is a boat equipped with an intake port and an exhaust port, with at least one and preferably several arrays of cutting blades disposed between said intake and said exhaust ports such that any solid matter is mulched or cut into tiny pieces upon passage from said intake port on its way to said exhaust port, said intake port being disposed so as to allow plant infested water to enter the boat and come into contact with said array or arrays of cutting blades.

Abstract: A fire detection system discriminates between a HEAT round that does not initiate a secondary fire and a HEAT round which does initiate a secondary fire. The system of the invention measures the peck intensity of a penetrating HEAT round in order to determine a secondary threshold level which is subsequently utilized to detect a resulting hydrocarbon fire. Also, the system performs a statistical analysis of the slope of the round thermal signature to determine if a secondary fire may be occurring.

Abstract: A fire sensing system utilizing fiber optics to extend the physical range of radiation sensing elements into areas and environments which are physically inaccessible to, and/or destructive of, such sensors and their associated electronic circuitry. The fiber optics are combined with signal processing circuitry to achieve reliable fire sensing systems which present particular advantages in special applications.