TM 55-1930-209-14&P-1
Section III. Voids ventilation system
7-6 Description. The void areas are provided with forced fresh air ventilation by electrically driven fans. Two fans
mounted high on deckhouse port and starboard bulkheads (Figure 7-5) provide ventilation to eight void areas, void 1 In
bow, voids 2 port and starboard, voids 3 port and starboard, voids 4 port and starboard and void 5 in stern In addition, two
fans mounted In ducting at rear of ROWPU space (Figure 7-6) exhaust hot air from voids 4, which contain three diesel
generators. Two louvered hatches, with covers and ducting, provide fresh air Intake from the stern weatherdeck into
voids 4 -one in port and the other in starboard. The voids ventilation system also includes air ducts, electrical wiring,
controls, and both mechanical and electrical emergency shutoffs. Major components are listed in Table 7-2.
7-7 Capabilities. This system provides sufficient change of air In the voids to maintain safe working conditions under
normal operations.
7-8 Performance characteristics. Two fans mounted on port and starboard bulkheads each move air at the rate of
1887 cfm at 1/2 inch static pressure. Generator exhaust fans each move air from voids 4 at the rate of 8500 cfm at 1.06
inches static pressure
7-9 Operating instructions
7-9.1 Operating controls and indicators
a.
Circuit breakers 7P8 thru 10P8 controlling power to four voids ventilation fans are on power panel 2 on deckhouse
starboard bulkhead forward of sliding door. Figure 7-3 shows location of circuit breakers for specific fans.
b.
Voids ventilation fans 7, 9, and 10 are controlled by electric controllers with ON/OFF toggle switches. Raise
toggle switches to start fans. Lower toggle switches to stop fans. Starter/controller locations are shown In Figure
7-4.
c.
Voids ventilation fan 8 contains an electrical interlock for chlorination system and requires slightly different
procedures than for other voids ventilation fans. To start this fan, first move ON/OFF switch on top front of
controller to ON, then raise toggle switch to start fan. To stop this fan, lower toggle switch and then move
controller switch to OFF. This controller also contains a reset button that, when pushed, resets the Internal circuit
breakers for this fan and the electrical supply for the chlorination system.
7-9.2 Prestart procedures
a.
Open blower inlet covers high on exterior sides of ROWPU space and secure in open position with drop chains
(Figure 7-7).
b.
Remove two large, flat cover plates on louvered air Intake hatches on deckhouse stern bulkhead exterior (Figure
7-5). Secure with bolts to special storage mounting brackets on either-side of ventilator Intakes. These covers
must be removed before starting fan motors 9 and 10 and diesel generators in voids 4.
c.
Open all eight emergency ventilation shutoff valves (Figure 7-8). Six of these are on sides of ROWPU space, one
in dayroom, and one mounted overhead in void 4 port. Handles should be in vertical position in deckhouse and
parallel to air duct in void 4 port. Emergency ventilation shutdown valves are located In ventilation ductwork as
follows:
(1)
Void 1 - dayroom near starboard bulkhead
(2)
Void 2 starboard - ROWPU space near starboard bulkhead
(3)
Void 3 starboard - same as void 2 starboard farther aft
(4)
Void 4 starboard - same as void 3 starboard farther aft
7-8
