NFPA Journal - November/December 2017 - 75

and pump system and asked vendors
to design and build something scalable that could work. Three vendors
came back with viable options; all are
designed uniquely for the project and
in use at sprinklered FEMA homes
today. While all slightly different, each
has the same basic design. The external tank and pump are housed in a
heated and insulated box to ensure
that the water and components will be
functional in case of a fire, whether on
the coldest winter night or warmest
summer day. A high-strength insulated
industrial rubber hose, housed in hard
plastic pipe to prevent rodents from
gnawing on it, connects the tank and
pump to the home via quick-connect
couplings. Flow alarms trigger a horn
and strobe assembly if the sprinkler
system is activated. The tank and pump
system also has a maintenance alarm
that will go off when the temperature
inside the box or hose drops below 40
degrees F.
"The entire tank and pump assembly
is designed to be plug and play, because
these need to be made operable in the
field by plumbers, electricians, and
carpenters," McKenna told a room full
of engineers during a presentation
on the sprinkler system at the NFPA
Conference & Expo in June 2016. "We
can't send a sprinkler fitter into the
field for every one of these. The water
tank is filled with a water hose during
the install and testing, then the system
hose is connected and you walk away
from it-simple."

'Make this thing happen'

Other issues required less dramatic,
but equally crucial, solutions. To deal
with the pounding the units can be
subjected to during transport over
thousands of miles of highway, the
engineers chose more rugged components than those used in a typical
installation. For instance, pipe hangers
were ruggedized by requiring anti-chafing features for the CPVC pipe, and
they were also spaced much closer
together than in traditional installations. In addition, the sprinkler riser,
which extends below the floor of the
unit, is made of schedule 40 galvanized
steel, and is protected against damage

from roadway hazards, insects, and
other vermin. To address the stresses
of sitting in the heat and cold for years
before deployment, the team carefully
chose specific kinds of sprinkler parts,
such as glass bulb sprinklers instead of
eutectic metal elements. Research has
shown that repeated exposure to high
heat can cause chemical changes in
eutectic metal alloy that can decrease
its melting temperature, McKenna
said. "We didn't want our inspectors
to go into the storage lot one day for
the monthly inspection and find all the
sprinklers popped," he said. Other parts
that could be affected by exposure to
heat or cold over time, such as the soldered sprinkler cover plates, are stored
in the manufactured home's refrigerator, where temperatures are more
stable, and installed just before the unit
is shipped to the deployment site.
While the design was being finalized, FEMA team members in charge
of acquisition contacted suppliers to
ensure that required parts would be
available on a large scale when the next
Katrina hit. "We had to get into every
single component on these systems to
figure out things like how many screws
we needed, how many feet of pipe,
how many elbows," McKenna said. "If
we have a scenario where we need 50
homes built per day, can the various
industries supply that? Can we get
5,000 feet of pipe every week? Turns
out we can."
Another logistical hurdle was squaring the FEMA sprinkler design with
the various unique home sprinkler
ordinances adopted across the country.
While most jurisdictions use NFPA
13D as the basis, many communities
amend the code before adoption. As a
result, neighboring communities can
have slightly different rules. Knowing
it would be impossible to comply with
every jurisdiction, FEMA staff made a
spreadsheet of requirements for every
sprinkler ordinance in the nation, and
called authorities having jurisdiction
(AHJs) to run certain requirements and
exceptions past them. Every AHJ that
FEMA contacted eventually signed off
on the sprinkler design. (None of the
sprinklered FEMA units in Louisiana or
elsewhere have yet experienced a fire

that has triggered a sprinkler, according to McKenna.)
Simultaneously, an opposite but
equally pressing practicality was
addressed. In jurisdictions without
sprinkler ordinances-which are the
majority-FEMA knew its units could
be the first home fire sprinklers that
many building officials, firefighters,
and residents had seen. So FEMA
crafted educational materials on home
sprinklers for local fire departments
and municipal officials. The agency
also collaborated with the Home Fire
Sprinkler Coalition to produce a document for occupants called "Living
With Sprinklers" that includes information on sprinkler myths, dos and
don'ts, and the unit's special water
tank and pump.
Members of FEMA's sprinkler team
worked nights and weekends to get it
done on time, and in September 2015,
just nine months after the team had
been assigned the task, FEMA took
delivery of the first sprinklered unit.
"We wanted to make this thing happen
while the iron was hot," McKenna said.

Meeting the
emergency need

Almost exactly two years later, Harvey
descended on greater Houston, resulting in what is likely the costliest
natural disaster in the United States
since Hurricane Katrina struck in 2005.
In no time, McKenna said, FEMA had
"a gazillion gears all turning at once."
FEMA ordered its manufacturers to
build 4,500 more sprinklered housing
units in addition to the 1,000 or so it
already had in inventory. Days later,
FEMA teams headed to the Houston
area to look for large empty parking
lots or open fields that could serve as
adequate staging yards for the units
when they arrived. All the while, devastated Texan families began applying for
FEMA aid en masse.
As of mid-October, the agency had
approved about $1 billion in individual
and household assistance for Harvey
victims. So far, more than 740,000
households have registered for FEMA
aid in nearly 40 Texas counties. Much
of the money will go toward housing
repairs, and providing temporary
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Table of Contents for the Digital Edition of NFPA Journal - November/December 2017
