OTTO FUEL II FACILITIES
FUNCTION. MK-46 and MK-48 torpedo facilities maintain, prepare, and
test torpedoes. MK-46 and MK-48 torpedoes use Otto Fuel II, a toxic monopropellant.
Toxins for additional design considerations.
OPERATIONAL CONSIDERATIONS. Operations in a torpedo facilities
create a potential for personnel exposure to one or more of the following: (1) Otto Fuel II,
(2) Agitene - parts cleaning solvent used in MK-46 shops, (3) hydrogen cyanide - a
product of combustion in torpedoes, and (4) mineral spirits - parts cleaning agent used in
DESIGN CRITERIA. Design the facilities using general technical
requirements in Chapter 2 of this handbook and the specific requirements in this Chapter.
Torpedo size differences and maintenance procedures dictate the use of different floor
plans and exhaust hood designs for the two types of facilities. Refer to NAVSEA OP5,
Production, Renovation and Shipping for the specific order of operations. In all cases, the
industrial ventilation systems must remove hazardous vapor (from Otto Fuel II, and part
Exhaust Air for MK-46 Ventilated Spaces
. The MK-46 floor plan
Figure 4-1 optimizes the workflow while allowing the ventilation system to control
airborne contaminants. Figure 4-2 shows an elevation view of this floor plan.
MK-46 Standup Backdraft Hood. Workers uncouple the fuel section and
the engine section of the torpedo in teardown operations. During these operations, Otto
Fuel II remains in the lines, in the components of the engine section, and in the fuel
tank. The residual fuel releases vapor into the air. The defueling and refueling
processes also release Otto Fuel II vapor. Use the standup backdraft hood as shown
on Figure 4-3 to capture Otto Fuel II vapor in afterbody teardown, fueling, and defueling
operations. Design criteria includes:
Capture velocity of 0.762 m/s (150 fpm) at the contaminant source.
b. Slots sized for 10.2 m/s (2,000 fpm) covered with wire mesh. The
wire mesh will prevent debris being drawn into the ventilation system.
Plenum velocity less than or equal to one half of the slot velocity.