furnace. If the crew could have got into the
engine compartment to reach the shutoff
valves first, they might well have stopped or
at least slowed the fire. In reality, it was too
hot to even think of getting close to the hatch.
Entering the engine compartment would have
been certain death. For this reason, I specify
remote fuel shutoffs on all my boats. These
are simple linkages (like throttle controls or
push-pull cables) that allow you to turn off
the fuel right at the tank without going near
the engine compartment—cheap insurance.
Flex Connectors
Vibration causes the hull, piping, and machin-
ery to work constantly. For this reason, con-
nections to the firmly mounted tanks and all
other components of the fuel system are best
made with flexible hose. You can get away with
rigid pipe connections to the tanks, if that’s
necessary, but you absolutely mustuse a flexi-
ble tubing or hose between the piping and the
engine or gen set. Fail to do this, and you’re
certain to get cracks—major trouble! Good
fuel-line hose isn’t all that expensive; it doesn’t
make sense to scrimp. In some instances, other
grades—like A2 or B1 hose—are permissible,
but ideally you should use all Coast Guard A1-
grade fuel-line hose. This hose meets SAE
J1527 (ISO 7840) specifications for hose con-
tinuously filled with fuel and withstands a 2^1 / 2 -
minute burn test. I would replace anything
else. Such hose is clearly labeled “A1” on the
outside—there’s no mistaking it.
SAE J1527 (ISO 7840)
Marine Fuel Hose Types
A1 FUELFEEDHOSE Designed for having
fuel in the hose all the time and with a fire-
resistant cover.
A2 FUELVENTHOSE Designed for applica-
tions with fuel not normally in the line and
with a fire-resistant cover.
B1 FUELFEEDHOSE Designed for having
fuel in the hose all the time but without a fire-
resistant cover. Intended for nonenclosed en-
gine spaces.
B2 FUELVENTHOSE Designed for applica-
tions with fuel not normally in the line and
without a fire-resistant cover. Intended for
nonenclosed engine spaces.
A2 FUELFILLHOSE Designed for applica-
tions with fuel not normally in the line and
with a fire-resistant cover.
B2 FUELFILLHOSE Designed for applica-
tions with fuel not normally in the line and
without a fire-resistant cover.
Unfortunately, A1 hose is not generally
available in sizes large enough for fuel fills. In
such a case, use A2 fuel fill hose.Holding Hose
Since you don’t want these hoses coming
loose, make sure there are marine-grade stain-
less steel hose clamps at each connection.
Naturally, the hoses have to be supported with
corrosion-resistant, chafe-free clips or hang-
ers. Pay special attention wherever hoses pass
through a bulkhead or panel. A rough edge
here is certain to wear through the toughest
material sooner or later. Protect the hose with
soft ring grommets installed in the hole.
ABYC-recommended fuel-hose clamp
widths are as follows:HoseOutsideDiameter Clamp Width(^7) / 16 in.and under (^1) / 4 in.
(^7) / 16 in.to (^13) / 16 in. (^5) / 16 in.
(^13) /
16 in.and over
(^3) /
8 in.
HoseOutsideDiameter Clamp Width
11 mm and under 6 .3 mm
11 mm to 20.5 mm 8 mm
20 .5 mm and over 9 .5 mm
CFR Yacht and ABYC require double^1 / 2 - inch-
wide (12.7 mm) clamps on all large-diameter
Chapter 4: Fuel Piping and Fuel System Bonding
Figure 4-13. A1
fuel hose