OTTO FUEL II

Otto Fuel II is the propellant for the propulsion system of the Mk 46 (all Mods) torpedo. Otto Fuel II is first sprayed under pressure into a combustion chamber where it is ignited. The exhaust gases from the burning fuel are used to drive the torpedo engine. The major advantage of this system is the short turnaround time required for exercise weapons.

Otto Fuel II is a stable, liquid monopropellant composed of a nitrate ester in solution with a desensitizing agent and a stabilizer. It is a bright red, free-flowing, oily liquid that is heavier than water. (NOTE: When in a thin layer, such as a spill, stain, or leak, Otto Fuel II is a yellow-orange color.) Otto Fuel _{II is noncorrosive.} It has an extremely low vapor pressure, minimizing explosive and toxic hazards. Otto Fuel II can detonate, but the conditions and stimulus required are so extreme that it is considered a nonexplosive. The propellant has a high flash point and other safety characteristics. It is classified as a low fire hazard material.

The ingredient of medical concern in Otto Fuel II is the nitrated ester. Nitrated esters are known for their acute effects on the human body. Symptoms of exposure to Otto Fuel II include the following:

Headache

Dizziness

Drop in blood pressure

Nasal congestion

NOTE: Depending upon the sensitivity of the individual, a temporary symptom-free tolerance may develop during the remainder of the working period. After exposure to a vapor-free environment, the first contact with Otto Fuel II vapor often causes these symptoms to recur.

A stowage space is specifically designated for each type of torpedo stowed aboard a combat ship. When handling Otto Fuel II, at least two crew members should handle the fuel. All personnel must know the general characteristics of Otto Fuel II, the safety precautions for

handling the fuel, and protective equipment required. To avoid hazardous situations when handling Otto Fuel II, personnel should be well trained and supervised. For further information concerning Otto Fuel II, you should refer to Otto Fuel II Safety, Storage, and Handling Instructions, NAVSEA S6340-AA-MMA010.

AIRCRAFT-LAID MINES

LEARNING OBJECTIVE: Identify aircraftlaid mines and recognize their classifications. Describe aircraft-laid mine components and identify operational aircraft mines.

Naval mines are used in offensive or defensive mining operations. The primary objective is to effectively defend or control vital straits, port approaches, convoy anchorages, and seaward coastal barriers.

Aircraft mine delivery is the principal method of making large scale mining attacks on enemy coastal and port areas. Aircraft-laid mines are usually carried and dropped in the same way as bombs, but they have different ballistic flight paths. Air-laid mines usually require parachutes that are released from the mine on water entry.

CLASSIFICATIONS

Mines are classified by intended use, method of delivery, position assumed when laid, method of actuation, or weight. Mines classified by their intended use are further classified as service, exercise (recoverable), and training mines. Service mines are fully explosive-loaded mines assembled with service components for use in wartime. Exercise (recoverable) and training mines are inert loaded to service weight. They have many uses, such as assembly and laying in fleet exercises. After exercise completion, they are recovered, analyzed, and overhauled for reuse. When assembled, exercise and/or training mines may contain minor explosive components.

Mines classified by method of delivery are submarine-laid, surface-laid, or air-laid. The classification depends on the laying vehicle.

Mines classified by the position they take in the water after being laid are moored or bottom mines. Bottom mines rest on the bottom of the sea. Their effective depth is controlled by the amount of charge they contain relative to the depth of the area in which ^{they are planted.} Their design includes sufficient negative buoyancy to provide good stability on the bottom of the sea.

Moored mines are buoyant mines. They are connected by cable to an anchor resting on the bottom (fig. 5-9). There are two important considerations in laying moored mines-stability and moored depth. Mine stability is achieved by an anchor with sufficient negative buoyancy to retain the mine in its position (without moving) on the bottom of the sea.

Mines are classified by the methods used to activate them. Methods of activation are contact and influence, or a combination of both methods. Influence-actuated mines are the only mines used tactically in an air-laid operation. Influence-actuated mines are further classified as magnetic, acoustic, or pressure mines.

Figure 5-9.-Aerial mine delivery sequence of moored mines.

These classifications are generally combined to describe a given mine; for example, an air-laid, pressure-fired, bottom mine or an air-laid, magnetic-fired, moored mine. Table 5-1 provides a list of the air-laid mines currently in use.

Table 5-1.-Air-laid Mines Currently in Use