Further observations on the durability of some common Indian timbers treated with creosote: fuel oil in Cochin harbour waters


Cheriyan, P.V.; Rao, M.V.; Cherian, C.J.

Journal of the Indian Academy of Wood Science 18(2): 69-77

1987


Seventeen-year data on resistance to marine borers are reported from tests with wood of 12 species (2 from various locations), untreated or treated with creosote/fuel oil (50:50) at 2 absorption levels (160 and 320 kg/msuperscript 3) [and suspended in iron frames below low tide]. The performance of the same species from different localities varied: samples of treated Shorea robusta from Uttar Pradesh were destroyed in 10-13 yr, while samples from West Bengal and Bihar (which absorbed more preservative) were still under exposure tests. Samples of Tectona grandis from Andhra Pradesh performed better than samples from Madras. Less than 60% destruction had occurred in samples of Terminalia paniculata, S. robusta (West Bengal), Pinus roxburghii, Tectona grandis (Andhra Pradesh), Dipterocarpus indicus and Xylia xylocarpa treated at the higher absorption level, while untreated controls of these species lasted only 2-8 yr. Non-durable timbers such as S. robusta (Bihar and West Bengal), P. roxburghii and Terminalia paniculata were as durable as relatively more durable species such as Tectona grandis (Andhra Pradesh), D. indicus and X. xylocarpa when treated. Differences in performance with original preservative loadings became more evident with time of exposure - generally a greater loading gave better durability. Other species for which data are reported are: Alstonia kurzi, Bombax insigne and Tetrameles nudiflora (all of poor durability, and rejected early in the trial), Albizzia [Albizia] sp., Polyalthia fragrans and Pterocarpus dalbergioides.

FURTHER
OBSERVATIONS
ON
THE
DURABILITY
OF
SOME
COMMON
INDIAN
TIMBERS
TREATED
WITH
CREOSOTE
:
FUEL
OIL
IN
COCHIN
HARBOUR
WATERS
By
P.V.
CHERIYAN*,
M.
V.
RAO*
and
C.
J.
CHERIAN**
Forest
Research
Laboratory,
Bangalore
Summary
Seventeen
year
data
collected
from
tests
conducted
in
Cochin
harbour
with
panels
selected
in
triplicate
from
fifteen
species
of
timbers
namely
Alstonia
kurzi,
Bombax
insigne,
Albizzia
sp.,
Tet-
rameles
nudiflora,
Pinus
roxburghii,
Polyalthia
fragrans,
Shorea
robusta
(Bihar,
U.P.
and
W.
Bengal),
Terininalia
peniculata,
Pterocarpus
dalbergioides,
Dipterocarpus
indicus,
Tectona
grandis
(Tamil
Nadu
&
Andhra)
and
Xylia
xylocarpa
and
treated
with
creosote:
fuel
oil
(50:50)
at
two
absorption
levels
of
160
kg/m3
(CI
series)
and
320
kg/m3
(C2
series)
along
with
untreated
controls,
are
presented.
The
data
are
analysed
to
assess
(a)
the
relative
performance
of
tl
e
timbers
tested
in
treated
and
untreated
conditions
and
(b)
the
relative
efficacy
of
the
two
absorption
levels.
It
is
found
that
the
performance
of
the
same
species
from
different
localities
varied.
While
treated
panels
of
S.
robusta
from
U.P.
were
destroyed
in
10
to
13
years,
those
from
W.
Bengal
and
Bihar
which
attained
higher
absorption
levels
are
still
under
exposure
tests.
Similarly,
treated
panels
of
T.
grandis
from
Andhra
showed
better
performance
over
the
species
from
Madras.
Treated
panels
of
T.
paniculata,
S.
robusta
(W.
Bengal),
P.
roxburghii,
T.
grandis
(Andhra),
D.
indicus
and
X.
xylocarpa
at
the
higher
absorption
level
(C2
series)
are
still
continuing
in
the
field
even
after
17
years
with
less
than
60%
destruction,
while
their
untreated
controls
lasted
only
for
2
to
8
years.
Non-durable
treated
timbers
such
as
S.
robusta
(Bihar
&
W.
Bengal),
P.
roxburghii
and
T.
paniculata
gave
a
duration
of
life
comparable
to
those
of
relatively
more
durable
species
like
T.
grandis
(Andhra),
D.
indicus
and
X.
xylocarpa
with
treatment.
Differences
in
the
performance
of
panels
due
to
differences
in
original
preservative
loadings
(C1
&
C2
series)
became
more
evident
with
longer
duration
of
exposure.
Introduction
Several
studies
on
the
durability
of
pre-
servative
treated
timber
against
the
attack
of
marine
wood-boring
organisms
in
Indian
waters
have
been
reported
by
various
authors
(Narayanamurti
&
Purushotham,
1956;
Anonymous,
1957;
Becker,
1958;
*
Wood
Preservation
Centre
(Marine),
Old
Railway
Station
Road,
Ernakulam,
Cochin-682
018.
**
College
of
Fisheries,
Panangad,
Cochin-682
506.
Nagabhushanam,
1961;
Ganapati
&
Naga-
bhushanam,
1964;
Jones,
1968;
Santhakuma-
ran,
1969;
Purushotham
&
Rao,
1971;
Cheriyan
&
Cherian,
1980
&
1983;
Krishnan,
Srinivasan
&
Jain,
1983).
Most
of
these
studies
excepting
two
are
based
on
data
col-
lected
for
a
maximum
period
of
three
years
only.
Performance
data
for
longer
periods
are
a
prerequisite
for
choosing
the
species
of
timbers
suitable
for
marine
constructions
and
determining
the
type
of
treatment
to
be
70
.1.
Ind.
Acad.
Wood
Sci.—Vol.
18,
No.
2,
1987
employed.
With
this
in
view
a
study
was
started
in
the
year
1967.
The
results
obtai-
ned
upto
1974
were
published
by
Cheriyan
&
Cherian
(1980).
The
present
paper
deals
with
data
for
seventeen
years
collected
upto
1983
on
the
performance
of
fifteen
species
of
common
Indian
timbers
treated
with
cre-
osote:
fuel
oil
against
the
attack
of
marine
wood-boring
organisms
in
the
Cochin
har-
bour
area.
Material
and
Methods
The
method
of
treatment
of
panels,
collection
of
data,
determination
of
destruc-
tion
of
the
panels
etc.
were
the
came
as
followed
by
Cheriyan
&
Cherian
(1978).
Three
test
panels
of
30
48
Y
3.81
x
1.81
cm
size
from
each
of
the
15
snecies
(Table
1)
of
timbers
were
pressure
treated
with
a
mix-
ture
of
creosote
and
fuel
oil
(50:50)
at
two
different
absorption
levels.
160
kg/m
3
(C1
series)
and
320
kg/m
3
(C2
series).
Of
the
15
species,
Xylia
xylocarpa,
Pterocarpus
dalbergioides,
Albizia
sp.,
Tectona
grandis
(Andhra
&
Tamil
Nadu)
and
Shorea
robusta
(U.P.,
Bihar
&
W.
Bengal)
did
not
take
the
required
absorption
levels
of
preservative
being
refractory
to
treatment.
The
absorp-
tion
level
in
X.
xylocarpa
varied
from
32
kg!
m
3
to
64
kg/m
3
,
in
S.
robusta
(U.P.)
from
64
kg/m
3
to
96
kg/ms,
and
in
the
rest
of
the
species
from
128
kg/ms
to
192
kg/m
3
.
The
panels
which
had
higher
levels
of
absorption
were
included
in
C2
series.
S.
robusta
was
selected
from
three
states,
Bihar,
U.P.
and
W.
Bengal
and
T.
grandis
from
two
states,
Tamil
Nadu
and
Andhra.
For
purposes
of
discussion
the
species
selected
from
each
state
is
considered
separately.
The
percent-
age
of
destruction
in
the
discarded
panels
was
taken
as
100.
The
average
percentage
of
destruction
in
the
test
panels
used
in
tri-
plicate
was
calculated
for
each
species
of
timber.
Results
and
Discussion
The
fouling
organisms
which
settled
on
the
panels
and
the
species
of
borers
which
destroyed
them
continued
to
be
the
same
as
reported
by
Cheriyan
&
Cherian
(1980).
As
years
passed,
irrespective
of
the
species
of
timber
and
the
kind
of
treatment
imparted,
destruction
of
panels
by
borers
continued
though
in
varying
degrees.
Cl
Series
Cheriyan
and
Cherian
(198n)
reported
that
within
a
period
of
eight
years
of
exno-
sure
to
sea
water
both
treated
and
untreated
panels
of
three
species
namely
A.
kurzi,
B.
insigne
and
T.
nudiflora
had
to
be
discarded.
The
best
resistance
in
this
series
was
shown
by
D.
indicus
and
X.
xylocarpa
with
an
ave-
rage
destruction
of
24%
and
27%,
respecti-
vely.
These
were
followed
by
T.
grandis
(Tamil
Nadu)
with
28%
and
T.
grandis
(Andhra)
with
30%
destruction
and
in
re-
maining
8
species
destruction
varied
from
32%
to
63%.
Table
1
shows
that
at
the
end
of
17
years,
D.
indicus
continued
to
be
the
best
borer
resistant
species
with
55%
destruction.
X.
xylocarpa
which
had
shown
resistance
al-
most
equal
to
that
of
D.
indicus
at
the
end
of
8
years
of
exposure
did
not
continue
to
show
the
same
level
of
performance
in
the
subsequent
years
and
sustained
71%
des-
truction.
T.
grandis
(Tamil
Nanu)
which
had
only
28%
destruction
at
the
end
of
8
years
also
failed
to
show
the
same
level
of
resistance
and
suffered
78%
destruction,
Durability
of
Some
Common
Indian
Timbers
71
whereas
the
same
species
from
Andhra
sus-
tained
comparatively
lesser
destruction
(58%).
Panels
of
S.
robusta
from
U.P.
were
all
discarded
in
the
1
1
th
year,
but
those
from
Bihar
and
W.
Bengal
continued
with
77%
and
57%
destruction,
respectively
at
the
end
of
the
17th
year.
T.
paniculata
and
P.
delbergioides
continued
with
almost
an
equal
level
of
resistance
at
the
end
of
17
year
of
exposure
with
86%
and
87%
destru-
ction,
respectively.
P.
roxburghii
continued
with
75%
damage,
whereas
P.
fragrans
was
rejected
in
the
15th
year
and
Albizia
sp.
in
the
17th
year.
C2
Series
At
the
end
of
eight
years
of
study,
Cheriyan
&
Charian
(1980)
reported
that
from
C2
series
treated
panels
of
only
one
species
of
timber
namely
B.
insigne
had
to
be
discarded.
The
most
resistant
species
in
this
treatment
series
was
D.
indicus
which
sustained
only
17%
destruction.
Next
to
it
came
P.
delbergioides
with
21%
destruction.
P.
fragrans,
T.
peniculata,
X.
xylocarpa,
T.
grandis
(Andhra)
and
T.
grandis
(Tamil
Nadu)
had
more
or
less
the
same
extent
of
destruction
varying
from
27%
to
31%.
S.
robusta
from
Bihar
and
W.
Bengal
behaved
almost
the
same
way
with
34%
and
36%
destruction,
respectively,
but
that
from
U.P.
had
suffered
78%
destruction.
The
perfor-
mance
of
P.
roxburghii
was
found
to
be
as
good
as
that
of
S.
robusta
from
Bihar
with
a
destruction
of
34%.
In
the
remaining
three
species
i.e.
Albizia
sp.,
A.
kurzi
and
T.
nudiflora
the
destruction
was
52%,
57%
and
82%,
respectively.
A
scrutiny
of
Table
1
will
show
that
at
the
end
of
17
years
also,
the
best
perform-
ance
was
shown
by
D.
indicus
with
27%
destruction.
The
next
best
species
in
the
previous
report
was
P.
dalbergioides,
but,
it
became
more
susceptible
to
destruction
by
borers
during
the
subsequent
years
and
had
to
be
discarded
in
the
16th
year.
P.
fragrans
whose
performance
was
equal
to
those
of
T.
paniculata,
T.
grandis
(Tamil
Nadu
&
Andhra)
and
X.
xylocarpa,
succumbed
to
borer
attack
in
the
12th
year.
T.
grandis
(Andhra)
and
T.
grandis
(Tamil
Nadu)
showed
wide
difference
in
their
perform-
ance,
the
latter
sustaining
75%
destruction
against
57%
in
the
former.
T.
paniculata
showed
53%
and
X.
xylocarpa
51%
destruc-
tion.
S.
robusta
from
U.P.
continued
to
be
a
less
resistant
species
and
was
discarded
in
the
14th
year
and
S.
robusta
from
W.
Bengal
with
56%
destruction
retained
its
better
per-
formance
over
the
same
species
from
Bihar
with
64%
destruction.
P.
roxburghii
sustai-
ned
only
56%
destruction,
and
this
is
com-
parable
to
those
of
S.
rabusta
(W.
Bengal)
and
even
T.
grandis
(Andhra).
Of
the
re-
maining
species,
T.
nudiflora
was
discarded
in
the
9th
year
and
both
A.
kurzi
and
Albizia
sp.
in
the
13th
year.
A
comparative
study
on
the
duration
of
life
of
each
species
of
timber
tested
in
un-
treated
and
treated
conditions
based
on
data
provided
in
Fig.
1
will
show
that
A.
kurzi
and
B.
insigne
hardly
lasted
for
one
year
in
untreated
condition,
but
their
panels
in
Cl
series
lasted
for
7
and
6
years
and
in
C2
series
for
12
and
7
years,
respectively.
In
untreated
condition
Albizia
sp.,
T.
nudiflora,
P.
fragrans
and
S.
rabusta
(U.P.)
panels
had
a
life
of
2
years
only
but
their
panels
in
Cl
series
lasted
for
16,
5,
14
and
10
years
and
in
C2
series
for
12,
8,
11
and
13
years,
res-
pectively.
Again,
while
untreated
panels
of
72
.1.
Ind.
Acad.
Wood
Sci.—Vol.
18,
No.
2
P.
roxburghii,
S.
robusta
(Bihar),
S.
robusta
(W.
Bengal)
and
T.
paniculata
had
only
life
of
2
years,
their
panels
in
Cl
series
are
con-
tinuing
even
after
17
years
with
75%,
77%,
57%
and
86%
destruction
and
in
C2
series
with
56%,
64%,
56%
and
53%
damage,
res-
pectively.
While
untreated
panels
of
P.
dalbergioides
gave
a
life
of
5
years,
those
under
Cl
series
are
continuing
with
87%
destruction,
but,
all
panels
under
C2
series
were
destroyed
by
borers
by
the
end
of
the
16th
year.
The
possible
reasons
for
the
same
are
explained
later.
The
remaining
species
D.
indicus,
T.
grandis
(Tamil
Nadu),
T.
grandis
(Andhra)
and
X.
xylocarpa
in
un-
treated
condition
showed
a
life
of
7,
6,
7
and
8
years,
respectively,
but
in
Cl
series
the
panels
are
still
continuing
with
55%,
78%,
58%
and
71%
destruction
and
in
C2
series
with
27%,
75%,
57%
and
51%
destru-
ction,
respectively.
Advantage
of
preservative
treatment
is
clearly
seen
when
data
of
non-durable
tim-
bers
like
S.
robusta
(W.
Bengal),
S.
robusta
(Bihar),
P.
roxburghii
are
compared
with
those
of
durable
timbers
like
T.
grandis
(Tamil
Nadu),
T.
grandis
(Andhra),
X.
xylocarpa
and
D.
indicus.
While
P.
roxbur-
ghii,
S.
robusta
(W.
Bengal)
and
S.
robusta
(Bihar)
gave
only
2
years
of
life
in
untreated
condition,
the
remaining
species
mentioned
above
gave
a
life
of
6
to
8
years.
But,
in
treated
condition
under
Cl
series
P.
roxbur-
ghii,
S.
robusta
(Bihar),
T.
grandis
(Tamil
Nadu)
and
X.
xylocarpa
showed
more
or
less
the
same
extent
of
borer
resistance
as
the
destruction
in
them
varied
only
from
71%
to
78%.
Similarly,
in
the
same
series
S.
robusta
(W.
Bengal),
D.
indicus
and
T.
grandis
(Andhra)
also
exhibited
almost
the
same
degree
of
resistance
to
borers
as
the
destruction
in
them
varied
from
55%
to
58%
only.
In
C2
series
P.
roxburghii,
S.
robusta
(Bihar),
S.
robusta
(W.
Beagal),
T.
grandis
(Andhra)
and
X.
xylocarpa
gave
more
or
less
comparable
results
as
percent
destruc-
tion
in
them
varied
from
51
to
64
only.
In
the
earlier
study
based
on
data
colle-
cted
during
the
first
eight
years
of
the
expe—
riment
Cheriyan
and
Cherian
(1980)
have
reported
that
even
though
the
absorption
level
of
the
preservative
in
C2
series
was
double
that
in
Cl
series,
the
difference
in
the
durability
of
panels
in
the
two
series
was
not
conspicuous.
But
a
comparison
of
the
present
data
which
covered
17
years
(Table
1)
of
the
performance
of
the
panels
in
Cl
and
C2
series
of
each
species
clearly
shows
that
in
a
majority
of
cases
the
panels
in
C2
series
exhibited
a
superior
perform-
ance
over
those
in
Cl
series.
This
is
clear-
ly
seen
in
the
case
of
D.
indicus,
X.
xylocar-
pa,
S.
robusta
(Bihar
&
U.P.),
T.
paniculata,
P.
roxburghii,
A.
kurzi
and
T.
nudiflora.
In
the
remaining
species
a
few
did
not
show
any
glaring
difference
between
the
two
series
and
in
three
species
namely
P.
dalber-
gioides,
P.
fragrans
and
Albizia
sp.
the
panels
in
Cl
series
showed
slightly
better
performance.
The
reasons
for
the
same
are
also
discussed
later.
The
apparent
equality
in
the
efficacy
between
Cl
and
C2
series
during
the
early
part
of
the
experi-
ment
(upto
8
years)
and
the
conspicuous
superiority
of
C2
series
during
the
later
period
is
very
likely
due
to
the
continuous
leaching
of
preservative
from
the
panels
and
the
consequent
fall
in
the
retention
level
of
preservative
in
them.
The
panels
of
Albizia
sp.,
T.
nudiflora,
P.
roxburghii,
P.
fragrans,
S.
robusta
(Bihar,
Durability
of
Some
Common
Indian
Timbers
73
U.P.
&
W.
Bengal)
and
T.
paniculata
showed
identical
natural
durability
of
2
years
(Table
1).
A
scrutiny
of
Table
2
shows
that
T.
nudiflora,
P.
roxburghii,
P.
fragrans
and
T.
paniculata
had
more
or
less
the
same
preser-
vative
absorption
levels
in
Cl
and
C2
series.
But
panels
of
T.
nudiflora
gave
life
of
5
and
8
years
and
those
of
P.
fragrans
14
and
11
years
only,
in
Cl
and
C2
series,
respecti-
vely,
whereas
those
of
P.
roxburghii
and
T.
paniculata
are
still
continuing
in
the
field
even
after
17
years
with
75%
&
56%
and
86%
&
53%
destruction
in
Cl
and
C2
series,
respectively.
This
difference
of
be-
haviour
amongst
species,
inspite
of
almost
identical
original
preservative
absorption
level
in
panels,
suggests
that
the
difference
in
degree
of
destruction
of
panels
in
the
above
cases
in
due
course
of
time
must
be
due
to
the
leaching
out
of
preservative
from
them
to
such
low
levels
as
they
could
be
attacked
by
borers.
As
the
panels
of
T.
nudiflora
were
the
first
to
be
destroyed,
pre-
sumably
leaching
was
at
the
fastest
rate
in
that
species
followed
by
P.
fragrans
which
gave
comparatively
longer
life.
Since
pa-
nels
of
P.
roxburghii
and
T.
paniculata
are
still
continuing
in
the
field,
though
with
cer-
tain
percentage
of
destruction,
leaching
of
the
preservative
from
them
is
presumably
at
a
lower
rate
than
in
other
species.
The
variations
in
leaching
rate
from
different
species
of
timber
under
the
same
environ-
mental
conditions
may
be
due
to
the
differe-
nces
in
permeability.
The
weight
of
the
timber
does
not
appear
to
have
a
direct
bea-
ring
on
the
resistance
of
the
species.
Variations
in
the
data
of
Table
2
for
a
given
species
selected
from
different
locali-
ties
indicate
that
higher
absorption
levels
of
preservative
in
general
impart
higher
resis-
tance
to
attack.
Thus
panels
of
S.
robusta
from
U.P.
had
average
absorption
levels
of
64
kg/m
3
and
80
kg/m
3
in
Cl
and
C2
series,
respectively
and
were
destroyed
in
10
and
13
years,
while
panels
of
the
same
species
from
Bihar
and
W.
Bengal
having
higher
preservative
absorption
levels
are
still
con-
tinuing
in
the
field.
Upto
nine
years,
T.
grandis
from
Tamil
Nadu
and
Andhra
show-
ed
more
or
less
the
same
level
of
resistance
both
in
Cl
and
C2
series.
But,
as
the
time
passed,
specimens
from
Andhra
showed
better
performance
due
to
the
comparatively
high
level
of
preservative
absorption.
Certain
results
of
Table
I
are
not
quite
expected.
For
example,
in
C2
series
all
the
three
panels
of
P.
dalbergioides
had
to
be
rejected
during
the
16th
year
of
experiment,
but
the
panels
of
the
same
species
in
Cl
series
are
still
continuing
in
the
field
even
after
17
years
of
exposure,
though
with
87%
destruction.
Similarly,
in
case
of
Albizia
sp.
Cl
series
panels
were
rejected
only
in
17th
year,
whereas
C2
series
panels
had
to
be
dis-
carded
during
the
13th
year.
In
P.
fragrans
the
Cl
series
panels
were
discarded
only
during
the
15th
year,
whereas
C2
series
pa-
nels
were
rejected
in
the
12th
year.
The
reasons
for
the
failure
of
C2
series
panels
earlier
than
those
in
Cl
series
in
the
above
instances
are
not
quite
clear.
However,
in
the
early
part
of
the
experiment
some
of
these
panels
were
found
intensely
attacked
by
Martesia
sp.
and
Sphaeroma
spp.
exposing
the
interior
untreated
or
inadequately
treat-
ed
part.
In
such
cases
Martesia
sp.,
Sphae-
roma
spp.
and
teredinids
would
have
attack-
ed
the
panels
simultaneously
and
destroyed
them
much
earlier
than
the
expected
period.
74
J.
Ind.
Acad.
Wood
Sci.-Vol.
18,
No.
2,
1987
The
foregoing
discussion
clearly
shows
that
creosote:
fuel
oil
treated
panels
of
both
non-durable
species
like
T.
paniculata,
S.
robusta
(W.
Bengal)
and
P,
roxburghii
and
of
relatively
more
durable
species
like
T.
grandis
(Andhra),
D.
indicus
and
X.
xylo-
carpa
suffered
only
less
than
60%
destruc-
tion
in
17
years
of
exposure
in
sea
water.
It
has
been
demonstrated
that
certain
chea-
per
non-durable
timbers
after
proper
treat-
ment
and
screening
can
be
used
for
under-
water
marine
structures
in
place
of
costly
and
scarce
species
of
timbers.
Since
treated
thin
panels
of
the
above
timbers
suffered
only
less
than
60%
destruction
in
17
years,
much
more
duration
of
life
can
reasonably
he
expected
for
actual
treated
structures.
The
above
six
species
of
timbers
can
profit-
ably
be
used
after
treatment
in
the
construc-
tion
of
boats,
ships,
fender
piles,
jetty
piles,
stake
poles
etc.
Acknowledgements
Authors
are
grateful
to
Dr.
M.C.
Tewari,
Director
of
Forest
Products
Research,
F.R.I.
&
Colleges,
Dehradun,
Sri
S.N.
Sharma,
Head,
Forest
Research
Laboratory,
Banga-
lore,
Dr.
V.
Srinivasan,
Officer-in-Charge,
W.P.
Branch,
F.R.L.,
Bangalore
for
their
encouragement.
to
Dr.
C.V.
Kurian,
retired
Professor
&
Head
of
the
Department
of
Marine
Sciences,
University
of
Cochin
for
his
valuable
suggestions
and
to
Cochin
Port
Trust
authorities
for
having
provided
neces-
sary
facilities
to
conduct
the
test
at
one
of
their
jetties
in
the
Willingdon
Island.
References
1.
Anonymous
1957.
Protection
of
timber
again-
st
marine
organisms
attack.
Research
and
Indu-
stry,
2
(8):208-210.
2.
Becker,
G.
1958.
Report
to
the
Govt.
of
India
on
the
protection
of
wood
against
marine
bo-
rers.
F.A.O.
Report,
795:122.
3.
('herian
P.V.
&
C.J.
Cherian
1978.
Observa-
tions
on
the
natural
durability
of
fifteen
species
of
Indian
timbers
in
Cochin
harbour
waters.
J.
Timb.
Dev.
Assoc.
(India),
24
(1):25-29.
4.
Ibid
1980.
A
report
on
the
durability
of
some
common
Indian
timbers
treated
with
creosote:
fuel
oil
in
Cochin
harbour
waters.
Indian
For-
ester
106
(6):413-417.
5.
Ibid
1983.
Observations
on
the
durability
of
fifteen
species
of
CCA
treated
timber
in
Cochin
harbour.
Fish.
Tech.,
20
(2):123-125.
6.
Ganapati
P.N.
&
R.
Nagabhushanam,
1964.
A
preliminary
note
on
the
resistance
of
marine
borers
to
chemically
treated
timbers
in
Visakha-
patnam
harbour.
J.
Timh.
Dryers
&
Preservers
Assoc.
India,
10
(1)
:
13-16.
7.
Jones,
E.P.G.,
1968.
Preservation
of
wood
in
the
marine
environment.
International
Bio-
deteriorat
ion
Bulletin,
4:105-106.
8.
Krishnan,
R.V.;
V.V.
Srinivasan
&
J.C.
Jain,
1983.
Observations
on
the
biodeterioration
of
timber
in
and
around
Madras
harbcur
waters.
J.
Ind.
Acad.
Wood
Sci
,
14
(2):74-82.
9.
Narayanamurthi,
D.
&
A.
Purushotham,
1956.
Ascu
Wood
Preservative.
Indian
Forest
Records
(New
Series)
Wood
Preservation,
I
(1):1-92.
10.
Nagabhushanam,
R,
1961.
Response
of
marine
borers
to
chemically
treated
timbers.
American
Zoologist,
1
(3):242.
11.
Purushotham,
A.
&
K.S.
Ran,
1971.
The
First
Progress
Report
of
the
Committee
for
the
Pro-
tection
of
Timber
against
Marine
Organisms
Attack
in
the
Indian
Coastal
Waters
for
the
Period
1953-70,
J.
Timb.
Dev.
Assoc.
(India),
17
(3):1-74.
12.
Santhakumaran,
L.N.,
1969.
Preliminary
ob-
servations
on
the
relative
resistance
of
selected
species
of
Indian
timber
to
gribble
(Limnoria)
attack.
J.
Bombay
Nat.
Hist.
Soc.,
66
(1):203-
210.
76
J.
Ind.
Acad.
Wood
Sci.--Vol.
18,
No.
2,
1987
TABLE
2
Average
preserservative
intake,
duration
of
life/percent
destruction
in
test
panels
and
unit
weight
of
the
species
SI.
No.
Species
Average
preservative
intake
(kg/m3
)
Duration
of
life/percent
des-
truction
at
the
end
of
17
years
Weight*
(kg/m3
)
Cl
series
C2
series
Cl
series
C2
series
1.
Albizia
sp.
171
176
16
years
12
years
2.
T.
nudiflora
(maina)
149
341
5
years
8
years
320
3.
P.
roxburghii
(chir)
181
320
75%
56%
575
4.
P.
fragrans
(debdaru)
176
320
14
years
11
years
640
5.
S.
robusta
(Bihar)
(sal)
155
171
77%
64%
865
6.
S.
robusta
(U.P.)
(sal)
64
80
10
years
13
years
865
7.
S.
robusta
(W.
Bengal)
(sal)
139
149
57%
56%
865
8.
T.
paniculata
(kindal)
161
309
86%
53
%
770
*IS
:
399-1963
Indian
Standard
Classification
of
Commercial
Timbers
and
their
Zonal
Distribution
(Revised).
U
UNTREATED
CONTROL
CI
SERIES.
0
C2
SERIES
El
%
DESTRUCTION
100
90
80
70
DES
T
RUC
TION
60
50
_40
—30
ui
cr
Lai
20
a_
10
D
ur
ab
il
i
t
y
of
S
o
m
e
C
o
mmon
I
nd
i
a
n
Ti
mb
ers
I
7
1
6
1
4
1
2
6
4
2
A.
/
/
/.
/
/
/
4
ALK—
Alstonia
kurzi
BI—
Bombax
insigne
ALE—
Albizia
sp.
TN—
Termeles
nudiflora
PR—
Pima
roxburghli
PF—
Polyalthia
fragrans
SR—
(B)
Shorea
robusta
(Bihar)
SR—
(W.B.)
Shorea
robusta
(West
Bengal)
SR—
(U.P.)
Shorea
robusta
(U.P.)
TP—
Terminalia
paniculata
PID—
Pterocarus
dalbergioides
DI—
Dipterocarpus
indicus
TG
(M)—
Tectona
grandis
(Tamil
Nadu)
TG
(A)
Tectona
grandis
(Andhra)
XX—
Xylia
xylocarpa
ALK
B1
ALB
TN
PR
PF
SR
(B)
SR(UP)
SR(W.B)
T
P
PTD
DI
TG(M)
TG(A)
X X
FIG
1
HISTOGRAM
SHOWING
DURABILITY
AND
PERCENT
DEcTRUCTION
OF
15
SPECIES
OF
TIMBER
IN
UNTREATED
AND
TREATED
(C1
AND
C2
SERIES)
CONDITIONS
IN
MARLNE
ENVIRONMENT