Cruising World - November - December 2016

MONTHLY MAINTENANCE

WW

W

hen I recently asked a

boatbuilder what type

of portable fi re extinguisher

he installed aboard his boats,

the response took me aback.

“Does it really matter?” he

asked. “Aren’t they all pretty

much the same?” Given the

alphabet soup by which fi res

and extinguishers are defi ned

and designated (see “U.S. Fire

Classifi cations”), his answer

could be forgiven. However,

there are signifi cant dif erences

between such designations.

While fi re classifi cations

might be familiar to some, the

ratings of fi re extinguishers

— for instance, 1A and 10B:C

— are often enigmatic. For

Class A fi res, a 1 represents the

equivalent of 1.25 gallons of

water; 2 the equivalent of 2.5

gallons of water; 3 the equiv-

alent of 3.75 gallons of water;

and so on. For Class B and C

fi res, the number represents

the square footage of the area

the extinguisher would cover.

The sui x in Roman numerals

that is used with marine fi re

extinguishers, such as in B-I

and B-II, represents the rela-

tive extinguisher capacity (the

larger the number, the greater

the content). Sizes I and II

are the most common extin-

guishers for recreational craft,

while size III is found aboard

larger and commercial vessels.

The most common and

inexpensive portable fi re

extinguishers rely on dry

chemical agents, including

sodium or potassium bicar-

bonate. Ammonium

polyphosphate, the familiar

white powder used in Class

B:C extinguishers, can have a

detrimental ef ect on mechan-

ical and electrical equipment,

particularly if ingested by a

running engine or if used on

or near sensitive electronics.

Monoammonium phosphate,

often used in extinguishers

with an otherwise desirable

ABC rating, is a pale yellow

color and is quite corrosive,

particularly if exposed to

water or even high humidity.

Furthermore, the manner in

which this agent works (the

powdered agent melts to

smother the fl ames) makes

cleanup especially dii cult.

On the other hand, gaseous

fi re extinguishers — like the

permanent units installed in

some engine compartments

— rely on a clean agent, one

that leaves no residue and will

not harm engines, machinery,

or electrical and electronic

equipment when discharged

nearby or even directly onto

those components. For por-

table extinguishers, gaseous

units are especially ef ective

on small electrical fi res of the

type that might occur behind

consoles, or in electrical

panels and engine compart-

ments. They are an adjunct to,

rather than a substitute for, a

dry-chemical extinguisher, as

they are not ef ective on Class

A and B fi res unless fl ooding

an enclosed compartment.

Portable clean-agent extin-

guishers are available in a

variety of agents and sizes,

including FM-200, FE-36,

Halotron and CO2, in every-

thing from 1.5 pounds (this is

very small, designed for light

aircraft and automobiles) to

20 pounds. Ideally, at least

one clean-agent extinguisher

should be installed in a cen-

tral location. While these

extinguishers are more expen-

sive than their dry-chemical

counterparts, the damage

they can help prevent will

more than pay for the addi-

tional cost if discharged.

The U.S. Coast Guard

requirements for fi re extin-

guishers are, in my opinion,

woefully inadequate and should

be considered strictly an abso-

lute minimum. A 65-foot vessel

is compliant with just one por-

table B-II and one fi xed fi re

extinguisher (again, I don’t

recommend following this

guideline). My preference is

for a portable ABC unit to be

installed in every cabin, along

with one clean-agent extin-

guisher mounted amidships,

typically close to the engine

and electrical panel. And no

fi re extinguisher should be

more than three steps away.

Review your vessel’s fi re-

fi ghting capability. Augmenting

it is often relatively inexpensive

and is money well spent.

Steve D’Antonio o ers

services for boat owners

and buyers through Steve

D’Antonio Marine Consulting

(stevedmarineconsulting.com).

MONTHLY MAINTENANCE

W

hen I recently asked a

WWboatbuilder what type

of portable fi re extinguisher

he installed aboard his boats,

the response took me aback.

“Does it really matter?” he

asked. “Aren’t they all pretty

much the same?” Given the

alphabet soup by which fi res

and extinguishers are defi ned

and designated (see “U.S. Fire

Classifi cations”), his answer

could be forgiven. However,

there are signifi cant dif erences

between such designations.

While fi re classifi cations

might be familiar to some, the

ratings of fi re extinguishers

— for instance, 1A and 10B:C

— are often enigmatic. For

Class A fi res, a 1 represents the

equivalent of 1.25 gallons of

water; 2 the equivalent of 2.5

gallons of water; 3 the equiv-

alent of 3.75 gallons of water;

and so on. For Class B and C

fi res, the number represents

the square footage of the area

the extinguisher would cover.

The sui x in Roman numerals

that is used with marine fi re

extinguishers, such as in B-I

and B-II, represents the rela-

tive extinguisher capacity (the

larger the number, the greater

the content). Sizes I and II

are the most common extin-

guishers for recreational craft,

while size III is found aboard

larger and commercial vessels.

The most common and

inexpensive portable fi re

extinguishers rely on dry

chemical agents, including

sodium or potassium bicar-

bonate. Ammonium

polyphosphate, the familiar

white powder used in Class

B:C extinguishers, can have a

detrimental ef ect on mechan-

ical and electrical equipment,

particularly if ingested by a

running engine or if used on

or near sensitive electronics.

Monoammonium phosphate,

often used in extinguishers

with an otherwise desirable

ABC rating, is a pale yellow

color and is quite corrosive,

particularly if exposed to

water or even high humidity.

Furthermore, the manner in

which this agent works (the

powdered agent melts to

smother the fl ames) makes

cleanup especially dii cult.

On the other hand, gaseous

fi re extinguishers — like the

permanent units installed in

some engine compartments

— rely on a clean agent, one

that leaves no residue and will

not harm engines, machinery,

or electrical and electronic

equipment when discharged

nearby or even directly onto

those components. For por-

table extinguishers, gaseous

units are especially ef ective

on small electrical fi res of the

type that might occur behind

consoles, or in electrical

panels and engine compart-

ments. They are an adjunct to,

rather than a substitute for, a

dry-chemical extinguisher, as

they are not ef ective on Class

A and B fi res unless fl ooding

an enclosed compartment.

Portable clean-agent extin-

guishers are available in a

variety of agents and sizes,

including FM-200, FE-36,

Halotron and CO2, in every-

thing from 1.5 pounds (this is

very small, designed for light

aircraft and automobiles) to

20 pounds. Ideally, at least

one clean-agent extinguisher

should be installed in a cen-

tral location. While these

extinguishers are more expen-

sive than their dry-chemical

counterparts, the damage

they can help prevent will

more than pay for the addi-

tional cost if discharged.

The U.S. Coast Guard

requirements for fi re extin-

guishers are, in my opinion,

woefully inadequate and should

be considered strictly an abso-

lute minimum. A 65-foot vessel

is compliant with just one por-

table B-II and one fi xed fi re

extinguisher (again, I don’t

recommend following this

guideline). My preference is

for a portable ABC unit to be

installed in every cabin, along

with one clean-agent extin-

guisher mounted amidships,

typically close to the engine

and electrical panel. And no

fi re extinguisher should be

more than three steps away.

Review your vessel’s fi re-

fi ghting capability. Augmenting

it is often relatively inexpensive

and is money well spent.

Steve D’Antonio o ers

services for boat owners

and buyers through Steve

D’Antonio Marine Consulting

(stevedmarineconsulting.com).

Clockwise from top: Dry-chemical extinguishers are most common, but dif er in signifi -

cant ways. Having a fi re extinguisher in every cabin makes good sense. Because they leave

no harmful residue, clean-agent extinguishers are ideal for small electrical fi res.

HANDS-ON SAILOR

4 FLAME OUT

So what’s the di erence between one portable fi re extin-

guisher and another? The answer might surprise you.

BY STEVE D’ANTONIO

STEVE D’ANTONIO

The following list details

how fi res are classifi ed in

the United States. This list

dif ers slightly in Europe,

Australia and other locales.



Class A: Wood, paper,

cloth, trash and other

ordinary materials.



Class B: Gasoline, diesel

fuel, oil, paint and other

fl ammable liquids.



Class C: Live electrical

equipment. (Once the

electricity is removed,

these fi res typically

become Class A; ideally,

electricity should be shut

of before fi ghting the fi re.)



Class D: Combustible

metals (for example,

magnesium, titanium and

potassium).



Class K: Cooking fi res,

fats and oils.

U.S. FIRE

CLASSIFICATIONS

november/december 2016

cruisingworld.com

101