firerescue.hotims.com FIREFIGH TERNATION. COM
You want to be able to flow a big water line
for the areas that the deck gun can’t reach. A
flow of 265 gpm is suggested and possible.
To make this operation as simple as possible
one size handline is used to obtain all flows;
it is two-inch hose with 2½-inch couplings.
This hose is just a couple of pounds heavier
than 1¾ inch and the maneuverability of it
is not much of an issue because the lines will
more than likely not go interior. These lines
are connected to any of the manifolds in the
evolution or to the attack pumper if used.
Dialing in the correct discharge pressure is
done at the manifold or the pumper if used.
A simple reference chart should be designed
to show the friction loss for each flow based
on a 50-foot section of hose and based on the
type of nozzle being used; the nozzle pressure
should also be added.
Since it will not be possible to set the
discharge pressure for the handline from the
manifold by the pumper, it has to be done at
the manifold itself. An inline gauge should
be placed between the discharge port of the
manifold and the handle and the pressure
should be set while the line is flowing.
FIXED MASTER STREAM
The main purpose of the master stream
is to knock the fire out of the burning
structure quickly. Water priority should be
given to the master stream. When effective,
the master stream can achieve a knockdown
in a minute or less. High-pressure smooth
bore tip operations are encouraged for deep
penetration and battling wind conditions.
Effective flow range should be between 500
and 1,000 gpm. If the master stream appli-
ance being used is a 2,000 gpm or higher
and the water is available, a 1,456-gpm flow
at 150 nozzle pressure can be produced safely.
It’s important to make sure all units are on the same
page as far as what evolution is to be used. A water
management officer should be used. The person
filling this position should be familiar with the
evolutions discussed, available water supply, units
involved, and available staffing.
Paul Shapiro is a 36-year veteran of the fire service and a retired
engineer from the Las Vegas (NV) Fire Department. He is director of
Fire Flow Technology and a national instructor on large-flow water
delivery. Shapiro has authored numerous articles for fire trade
magazines and a video on large-flow water delivery.
A 2½-inch × 2½-inch gated wye with gauge mounted on
the jumbo wye itself as well as connected to the outlet
before the hose. (Photo by author.)