for some large-diaphragm pumps, which we’ll
look at in a bit.) The open area of the grating
or mesh in the strum box should be at least
3 times the area of the suction pipe.
A manual bilge pump also can be portable
and stowed in a locker, but there needs to be
at least a couple of locations you can readily
set the pump for operation. Also, the hoses re-
quired to reach the sump and discharge over-
board must be permanently attached to the
pump and ready for immediate use. Again, a
hand bailer and a sponge should round out a
small-boat bilge system. There’s an old saying:
“There are few pumps more effective than a
frightened sailor with a bucket.”
If the boat has an electric system (virtu-
ally all modern powerboats and nearly all
sailboats large enough to have a cuddy
cabin), then it should be equipped with both
a manual pump and an electric bilge pump—
a true bilge system. On large vessels, the bilge
system is often referred to as being used for
dewatering, and bilge pumps may be referred
to as dewatering pumps.
Required Bilge-Pump
Capacity
There aren’t many regulations for pleasure-
craft pump capacity. We can refer to the CFR
for passenger vessels (CFR Commercial) and
to American Bureau of Shipping (ABS) Rules
for Motor Pleasure Yachts and for High-
Speed Craft for some guidance.
Table 18-1 is CFR 182. 520 ’s Table
182 .520(a), which gives the minimum required
pumping capacity for passenger vessels.
ADDITIONALREQUIREMENTS FORCFR
COMMERCIAL(CFR 182. 10 AND 182 .30)
- For vessels under 65 feet (19.8 m), min-
imum nominal pipe diameter is 1 inch
(DN 25 mm). - For vessels over 65 feet (19.8 m), mini-
mum nominal pipe diameter is 1^1 / 2 inches
(DN 38 mm). - The bilge suction must be fitted with a
suitable strainer with an area not less
than 3 times the pipe area. - If individual pumps are not provided for
separate spaces, then the bilge suction
lines should lead to a main control sta-
tion with an on/off valve to control oper-
ation and a check valve to prevent back
flow (or a combined stop-check valve). - The portable hand pump must be able
to pump water from each compartment
(but not necessarily at the same time or
from the same location). - Each bilge pump must be self-priming
and permanently connected to the
bilge-piping manifold and may also be
connected to the fire main. - Check valves must be installed at the
main piping manifold and where
needed to ensure that reverse flow can-
not take place. - If there are two power pumps, they
must each have a different power
source. One may be the main engine, or
on a twin-engine boat, each may be off
a separate main engine. - At the forward collision bulkhead, the
bilge suction pipe should have a valve
Chapter 18: Bilge Systems, Fire Mains, and Fire Extinguishers
TABLE 18-1. CFR 182.520(A) BILGE-PUMP TABLE
Minimum Capacity
Number of Passengers Length of Vessel Bilge Pumps Required Required per Pump
Any number More than 65 ft. (19.8 m) 2 fixed power pumps 50 gpm (190 lpm)
More than 49 Not more than 65 ft. 1 fixed power pump and 10 gpm (38 lpm)
passengers and all (19.8 m) 1 portable hand pump 10 gpm (38 lpm)
ferry vessels
Not more than 49 26 ft. (7.9 m) up to 65 ft. 1 fixed power pump and 10 gpm (38 lpm)
passengers (other (19.8 m) 1 portable hand pump or
than ferry vessels) 1 fixed hand pump and 10 gpm (38 lpm)
1 portable hand pump 5 gpm (19 lpm)
Less than 26 ft. (7.9 m) 1 portable hand pump 5 gpm (19 lpm)