ENGINE ROOM WATER WASHDOWN SYSTEM (ERWWS)

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TM 55-1925-292-14&P

ENGINE ROOM WATER WASHDOWN SYSTEM (ERWWS)

The purpose of the ERWWS is to quickly reduce the temperature in the protected space to minimize the produc-

tion of Hydrogen Fluoride (HF) gas generated as a result of FM-200 agent contact with hot surfaces and flame

above 1,300 F (704.4 C). The sprinkler water also acts to keep smoke particulate down and expedites venti-

lation of the compartment when the fire is extinguished. The ERWWS is not designed or intended to be a stand-

alone fire extinguishing system. It is designed to be used in conjunction with the installed FM-200 fire suppres-

sion system. Use of the ERWWS reduces the risk of HF exposure by reducing temperatures within the pro-

tected space.

The ERWWS is constructed of all stainless steel components. In order to operate the ERWWS, the fire main

must be charged and, at a minimum, fire and general service pump 1 must be online at maximum operating

pressure. To provide an adequate volume of raw water for the ERWWS, valves FM-17 and FM-15 must be

closed prior to activation of the ERWWS. The ERWWS requires a minimum of 145 gal/min (548.9 L/min) at 104

PSI (7.17 bar) to operate as intended.

Activation of the ERWWS is accomplished by opening WWS-1 (figure 11, item 1). WWS-1 is located in the

engine room vestibule on the main deck at Frame 25. The ERWWS shall be activated prior to actuation of the

FM-200 fire suppression system. The ERWWS is a Hydrogen Fluoride (HF) gas mitigating water washdown

system that provides general overhead coverage to the protected spaces. The ERWWS consists of simple

overhead sprinkler heads (figure 12) piped directly to the fire main. The ERWWS receives raw water directly

from fire and general service pump 1. Fire and general service pump 1 is powered by the Emergency Diesel

Generator (EDG) switchboard and will have to be restarted remotely from the pilothouse once the EDG comes

online.

OFF

JCV-PRO-3

Figure 11. Engine Room Water Washdown Station

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