243
1 INTRODUCTION
Throughout their operational lifespan, ships are
exposed to a wide range of environmental conditions
that significantly influence the degradation of ship
structures [1, 2]. These conditions primarily include
atmospheric exposure, external seawater, internal
ballast water, and operational factors such as loading
and unloading sequences [3, 4]. Consequently, ship
structures experience degradation due to corrosion,
most notably observed as thickness reduction in
structural elements [5, 6]. Hulls are particularly
susceptible to surface degradations that compromise
structural integrity and reduce service life of structural
elements. The type and severity of corrosion depend on
environmental conditions, operational duration,
maintenance practices, and navigation routes.
Corrosion mechanisms include general corrosion,
pitting, intergranular corrosion, galvanic corrosion,
stress corrosion, corrosion fatigue, fretting,
microbiologically influenced corrosion, crevice
corrosion, erosion, and cavitation [7].
Corrosion in ship structures has been extensively
investigated in the literature, mainly focusing on
protective coatings, identification of vulnerable hull
regions, effects on ship aging, and estimation of
corrosion rates [8]. Novel coatings that significantly
delay the onset of corrosion have been explored [9],
while the weight and effectiveness of corrosion
protectives during the design phase are highlighted by
[10]. Class NK’s investigation into corrosion-related
incidents emphasizes that ballast tanks and cargo holds
are particularly susceptible to corrosion damage [11].
Cargo holds, especially in single-skin bulk carriers, face
severe corrosion due to exposure to harsh external
environments, corrosive cargo and manipulative
equipment. Double-hulled ship designs, adopted in
recent decades, enhance structural integrity but also
present corrosion challenges, particularly in inner
bottom plating exposed to loading and unloading,
Lifetime Corrosion Loss of Bulk Carriers
N. Momčilović
1
, N. Kovač
2
& Š. Ivošević
3
1
University of Belgrade, Belgrade, Serbia
2
University of Donja Gorica, Podgorica, Montenegro
3
University of Montenegro, Kotor, Montenegro
ABSTRACT: This paper analyzes the total steel replacement due to corrosion degradation in four Handymax-
class bulk carriers, based on corrosion measurements recorded throughout their operational lifespan. Each ship
was divided into 11 lightship mass subgroups, enabling detailed examination of cumulative lifetime corrosion
losses for both entire ships and individual subgroups. Utilizing similar ship data obtained from the shipyard, the
study also provides estimations of the total steel weights of each of lightship subgroups. The findings offer
valuable insights into the overall aging effects on ship structures, crucial for maintenance planning, structural
integrity assessments, and recycling, especially from the perspective of sustainable shipping. Additionally, the
estimated weights of lightship subgroups can serve as reference data for preliminary ship design, aiding in the
estimation of lightship weights and potential steel loss due to corrosion.
http://www.transnav.eu
the International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 19
Number 1
March 2025
DOI: 10.12716/1001.19.01.28
244
ballast operations, and wet-dry cycles. Developing
accurate corrosion models necessitates extensive
datasets, including thickness measurements, to
estimate rates, predict degradation, and understand
corrosion evolution through initial protective phases to
active corrosion after coating failure.
Corrosion’s influence on structural degradation and
ship aging is well documented, though data on its
actual effects remain dispersed. The Committee
focusing on condition assessment of aging ships
reported extensively on this phenomenon [12], while
casualty reports highlight its impact [13, 14]. The
authors’ previous studies detail corrosion-induced
thickness diminution in inner bottom platings and
bottom longitudinal girders of bulk carriers [15, 16, 17].
Besides these studies, various corrosion models have
been developed, including non-linear rate models [18],
three-phase models [19], four-phase models [4, 20], and
five-phase models [21, 22], each offering methods for
estimating thickness diminution. On a larger scale, the
effect of corrosion on the hull girder ultimate strength
decay, considering both pitting and uniform corrosion,
is quantified in studies such as [23, 24].
Corrosion loss estimation is also important for ship
efficiency studies [25, 26, 27], with implications for
energy efficiency regulations [28]. Corrosion-induced
structural replacement is part of the issue regarding the
IMO’s recycling initiatives [29] and aligns with their
sustainable development goals [30].
Corrosion impacts the weight of structures,
especially the lightship mass. Estimation of lightship
mass has been explored using machine learning based
on main particulars [31], though primarily for tankers.
General procedures for preliminary design weight
estimation are provided by [32], with methods for
early-stage design as revised by [33]. However,
fundamental formulations for lightship mass
calculation, essential for ship design, are provided in
[34] and [35], with novel approaches proposed by [36].
Lightship mass distribution is critical for longitudinal
strength calculations, ship stability, overall mass
estimation, and cost assessments, as it governs the
deadweight capacity of the ship.
To summarize, dry cargo ships such as bulk carriers
are prone to accidents [37, 38, 39], particularly those
partially induced by structural degradation. Although
corrosion has been widely studied, most research
focuses on coatings, strength impacts, and corrosion
rate estimations, while comprehensive assessments of
total and cumulative corrosion loss in specific ship
parts are lacking. Such data are essential not only for
structural optimization and recycling but also for
estimating total renewal plating weights and lightship
mass, which are important for preliminary design
purposes. Ship weight estimation methods often
provide a single hull steel weight value without
differentiating between structural subgroups. This
study addresses that gap by offering a detailed
assessment of corrosion-induced steel loss across
different structural components in bulk carriers.
Therefore, the contribution of this paper lies in
several key aspects. The research delivers the total
amount of steel that was replaced due to corrosion in
four Handymax bulk carriers and their lightship
subgroups during their exploitation period (25 years).
Based on these data, and using the available data on
similar ship recordings, we calculated the original
weights of lightweight mass subgroups and their total
corrosion wastage mass loss during exploitation
period, offering valuable weight estimations which can
be used for future preliminary design purposes.
2 DATA ON SHIPS
Four Handymax-class bulk carriers are monitored over
the span of 25 years, depending on the particular ship.
Their deadweights (DWT) span between 38110 t to
44504 t, and their lengths between 187 and 199 m, with
two of them being sisterships. Although built in 1982
and 1983, ships exhibit standard cross-sectional
features of today’s similar size bulk carriers, which
include double bottom with hopper tanks, single skin
side with transversal framing and wing tanks, see
Figure 1 and Figure 2. At the time, ships were classed
by the most prominent classification societies, namely:
Bureau Veritas (BV) and Lloyd’s Register (LR). Their
main data with respect to their length over all, breadth,
year of built, years being monitored and corrosion
measured, class, gross tonnage (GT), deadweight
(DWT) and type of cargo carried during their service,
is provided in Table 1.
Table 1. Data on ships.
Ship
S2
S3
S4
Length overall
199
197.6
187
Breadth
29
28.3
28.40
Year of built
1982
1983
1983
Years monitored
25
25
25
Class
BV
LR
LR
GT
25056
25742
22112
DWT
44504
41427
38110
Type of cargo
Iron
ore
coal
Iron
ore
coal
Iron
ore
coal
To obtain the data on corrosion-induced
degradation of structural elements in ships, ultrasonic
measurements have been used over the lifespan of 25
years, depending on the particular ship from the
database, see Table 1. Measurements have been
collected by approved thickness measurement
company (see Acknowledgement). The measurements
were performed for almost all hull structures of the
bulk carriers, according to the rules and regulation of
classification societies. It should be noted, available
criteria for steel replacement were considered under
the specific rules and regulations the particular
classification society (BV or LR in these cases) in the
moment of gauging. Based on this corrosion
measurements, the total amount of replaced steel
weight is derived, see Table 2. The total amount of steel
in tons replaced during the monitored period is given
in Table 2. In there, ship lightweight mass is divided
into 11 subgroups, also see Figure 1 and Figure 2,
namely:
1. UD (upper deck). It extends from stern to bow,
between the ship sides. UD area consists of flat
plates, without stiffeners. This area is exposed to the
influences of ballast tanks and cargo holds
conditions, and to the multiple influences of
atmospheric from the upper side of the deck.
2. DS (deck superstructure). DS is located in the aft
part of a ship and above the upper deck and consist
of flat plates, without internal structures. Upper DS
245
is exposed to specific conditions of outdoor
atmosphere, while the lower DS is generally
insulated and situated in closed atmospheric
conditions.
3. BSSP (bottom and side shell platings). BSSP consists
of flat and curved plates (without internal
structures), which extend from the ship stern to
bow. The influences of atmosphere and seawater
form outside as well as the influences of ballast,
cargo and dry or wet air from inside render this area
specific and complex.
4. HCC (hatch cover and coaming). HCC consists of
both plates and internal structures of hatch covers
and hatch coaming structures. HCC ensures cargo
holds watertightness and is exposed to atmospheric
conditions.
5. ISTST (internal structure in top side tanks). ISTST
includes all internal transverse and longitudinal
structures, plates, brackets and stiffeners, as well as
all sloping plates. ISTST is exposed to the
changeable influences of ballast water or dry and
humid air inside the tank. The tanks are exposed to
atmospheric conditions from the outside (lateral
and upper side) and depending on the conditions
inside the holds, the tanks can be under the
influence of atmospheric conditions or the cargo
loaded.
6. CHTB (cargo holds transverse bulkheads). CHTB
gathers flat or corrugated plates including their
internal structures and stools, which are exposed to
the influences of the cargo transported and
atmospheric conditions inside the holds, when
there is no cargo in hold. As there are bulkheads
between adjacent holds, both sides of bulkheads are
exposed to the influences of these holds, which
significantly accelerates the decay of these
structural elements. In this structural area the
influence of manipulative operations is especially
notable.
7. CHMF (cargo holds main frames with brackets).
CHMF includes vertical stiffeners of shell plating
inside the holds. This structural area is under direct
influences of the medium, cargo and closed
atmospheric conditions inside the holds as well as
the skill at using the manipulative equipment.
8. IBHP (inner bottom and hopper platings). IBHP
represents the bottom of a cargo hold consisting of
steel plates which are under the direct influence of
cargo or atmospheric conditions inside the cargo
holds, and the influences of manipulative
equipment form the upper side. From the lower
side, the steel plates are exposed to the influences of
inner ballast tanks (i.e., ballast water and dry or
humid closed atmospheric conditions), fuel in the
fuel tanks and dry atmospheric conditions.
9. ISDBT (internal structure in double bottom tank).
ISDBT is a separate space at the bottom, wherein the
lower part verges on the external flat bottom, the
lateral parts on their sides rest on the vertical plates
and, on their lower end, against the internal bottom.
This area includes all internal structure area with
transversal and longitudinal plates, stiffeners and
brackets without surrounding platings.
Considering that the ship shell plating and the
cargo hold bottom are identified as separate areas,
the remaining structure of the tanks is seen as a
unique area, as well. Fuel, ballast, dry or humid air
could be found inside the tanks, while seawater,
cargo and atmosphere (within empty cargo holds)
affect from the outside.
10. APS (aft peak tank). APS is located in the stern part
of the ship. The inside of this area can be affected by
the medium inside the tank, e.g., technical or
drinking water, ballast water or dry and humid air
within the tank. This area includes all internal
structure area with transversal and longitudinal
plates, stiffeners and brackets without surrounding
areas, as well as tanks walls, except outer hull shell.
The outer side is framed by shell plating which is
affected by seawater, atmospheric conditions as
well as the influences of closed or semi-closed
atmospheric conditions.
11. FPS (fore peak tank). FPS is located in the front part
of a ship. Its outer side is covered with shell plating
and impermeable barrier separating it from the first
cargo hold and the cover which usually extents
toward the upper deck. This area includes all
internal structure area with transversal and
longitudinal plates, stiffeners and brackets without
surrounding areas, as well as tanks walls, except
outer hull shell. The inside of the tank is under the
influence of ballast water or dry and humid air,
while its outer side is framed by shell plating that is
affected by seawater, atmospheric conditions as
well as the influences of closed or semi-closed
atmospheric conditions.
Table 2. Data on the amount of steel replaced (∆mi) due to
corrosion in tons.
Ship/Lightship mass subgroup
-∆mi [t]
S1
S2
S3
S4
Average
1. UD
80
165
22
7
68.5
2. DS
5
22
6
6
9.75
3. BSSP
25
60
65
5
38.75
4. HCC
35
40
15
32
30.5
5. ISTST
120
160
9
75
91
6. CHTB
220
145
65
45
118.75
7. CHMF
110
85
45
32
68
8. IBHP
585
650
550
150
483.75
9. ISDBT
45
55
50
45
48.75
10. APS
12
30
40
14
24
11. FPS
55
60
6
32
38.25
Total (1-11)
1292
1472
873
443
1020
Figure 1. The lateral plan of a ship with subgroup
identification.
Figure 2. Cross section plan of a ship with subgroup
identification.
246
Furthermore, a “similar” ship data is given in Table
3. In there, data were obtained from the shipyard on
total weights in tons of 11 lightship subgroups and
depending on ship deadweights. This table will
provide a link to determine actual weight of 11 ships
subgroups in relation to their dependance on
deadweight. The data on bulk carriers used as a
“similar” ship are the following: 29850 GT, 52000 t of
DWT, 189.90 m (length overall), 32.24 m (width), Total
weights of all of 11 lightship subgroups equals to
14.76% of ship’s DWT.
Table 3. The amount of steel in tons and in relation to
deadweight in each of 11 lightships subgroups -obtained for
a “similar” bulk carrier.
Lightship mass subgroup
Share of subgroup weight to
deadweight – bi [%[
1. UD
0.81
2. DS
0.88
3. BSSP
2.99
4. HCC
1.35
5. ISTST
1.57
6. CHTB
1.20
7. CHMF
0.55
8. IBHP
1.62
9. ISDBT
2.68
10. APS
0.42
11. FPS
0.69
Total
14.76
3 METHODOLOGY
3.1 Original steel weight of the monitored structural
subgroups
The original steel weight of the replaced structure for
bulk carriers and their lightship subgroups (mi) can be
estimated using the data from the similar ship (Table
3), where the ratio between the steel structure
subgroup weight and a deadweight is given for an
available ship. Given that deadweights for ships are
provided, we can estimate their subgroup mass using
the relation from Eq. (1), in which mi is the estimated
weight mass of subgroups for four bulk carriers, bi is
the share of subgroup weight to deadweight (used
from Table 3), and DWTi is deadweight of each bulk
carrier.
i i i
m b DWT=
(1)
3.2 Share of steel weights replaced
By dividing the actual corrosion-induced steel weight
replaced (from Table 2) and estimated original
structure subgroup weights from Eq. (1), we can derive
the share of replaced corrosion-induced steel weight
for each of subgroups with respect to original weight
of the structure, see Eq. (2).
i
i
i
m
c
m
=
(2)
3.3 Corrosion wastage mass loss
Corrosion wastage mass loss is estimated considering
total amount of weights replaced and two criteria
which are commonly used by classification societies for
the decision elements renewal. This is assumed due to
lack of data on actual on-site requirements for element
renewal for each structural member. Namely, criteria
for renewal state that structural element has to be
replaced if the thickness diminution exceeds 15%, 20%
or 25% of the original as-built thickness, for instance
see [40, 41]. Thus, in this analysis, we used the average
criteria: 20%, see Eq (3). This implies that the calculated
mass of corrosion wastage represents a minimum
value, as, in practice, the corrosion wastage of replaced
elements meets or exceeds the stated criteria.
,
0.20
corr i i
mm=
(3)
4 RESULTS & DISCUSSIONS
Based on methodology given in sect. 3, results include
the calculated and estimated data regarding all
selected ships and their lightweight subgroups. Thus,
results consist of:
1. The total weights of steel replaced in each of 11
lightships subgroups (Figure 3), from Table 2.
Fitting curves are not given due to large dispersion
of data.
2. Estimated original weights of lightship mass
subgroups, for which the elements were replaced,
are provided in Table 4, as calculated according to
Eq. (1). Diagrams and corresponding linear fitting
curves based on data from Table 4 are shown in
Figure 4 and Table 5.
3. Total estimated minimum weight loss due to
corrosion wastage, for a 20% corrosion wastage
criterion, is given in Table 6.
4. The share of the total estimated minimum weight
loss due to corrosion wastage to ship deadweight is
shown in Figure 5. Fitting curves are not given due
to large dispersion of data.
Figure 3. The amount of steel replaced according to 11
subgroups.
Table 4. Estimated original weights of subgroups.
Ship/Lightship mass
subgroup
S1
S2
S3
S4
Average
1. UD
360.48
360.48
335.56
308.69
341.3
2. DS
391.64
391.64
364.56
335.37
370.8
3. BSSP
1330.67
1330.67
1238.67
1139.49
1259.9
4. HCC
600.80
600.80
559.26
514.49
568.8
5. ISTST
698.71
698.71
650.40
598.33
661.5
6. CHTB
534.05
534.05
497.12
457.32
505.6
7. CHMF
244.77
244.77
227.85
209.61
231.7
8. IBHP
720.96
720.96
671.12
617.38
682.6
9. ISDBT
1192.71
1192.71
1110.24
1021.35
1129.3
10. APS
186.92
186.92
173.99
160.06
177.0
11. FPS
307.08
307.08
285.85
262.96
290.7
Total (1-11)
360.48
360.48
335.56
308.69
6219.3
247
Figure 4. Estimated original weight of subgroups.
Table 5. Estimated original weights of subgroups: fitting
curve linear equations (R2 =1 for all curves).
Ship/Lightship mass subgroup
Equations
1. UD
m1=0.0081DWT+2E-11
2. DS
m2=0.0088DWT-2E-11
3. BSSP
m3=0.0299DWT+7E-11
4. HCC
m4=0.0135DWT
5. ISTST
m5=0.0157DWT
6. CHTB
m6=0.012DWT-2E-11
7. CHMF
m7=0.0055DWT-9E-12
8. IBHP
m8=0.0162x
9. ISDBT
m9=0.0268DWT
10. APS
m10=0.042DWT
11. FPS
m11=0.0069DWT+9E-12
Table 6. Corrosion wastage mass loss for 20% thickness
diminution criterion.
Ship/Lightship mass subgroup [t]
S1
S2
S3
S4
1. UD
16.0
33.0
4.4
1.4
2. DS
1.0
4.4
1.2
1.2
3. BSSP
5.0
12.0
13.0
1.0
4. HCC
7.0
8.0
3.0
6.4
5. ISTST
24.0
32.0
1.8
15.0
6. CHTB
44.0
29.0
13.0
9.0
7. CHMF
22.0
17.0
9.0
6.4
8. IBHP
117.0
130.0
110.0
30.0
9. ISDBT
9.0
11.0
10.0
9.0
10. APS
2.4
6.0
8.0
2.8
11. FPS
11.0
12.0
1.2
6.4
Total
240.8
265.4
163.3
77.9
Figure 5. Share of the total mass loss to deadweight for four
ships.
Figure 3 provides insights into the distribution of
steel replacement across 11 structural subgroups due to
corrosion, a dataset rarely found in existing literature.
This diagram serves as a valuable tool for early
estimation of the bandwidth range of corrosion-
induced losses. However, its application as a reliable
predictor is limited due to the significant data
dispersion observed, which suggests variability in
corrosion impacts across similar structural types and
operational conditions. Nonetheless, it is evident that
the inner bottom and hopper platings require the
highest amount of steel replacement due to corrosion,
which is understandable given their position and
exposure during loading and unloading operations. In
general, this is followed by the transverse bulkheads,
the internal structures of the top side tanks, and the
main frames of the cargo holds.
On the other, the estimated original weights of the
subgroups are derived from analogous data on similar
ships, as a function of deadweight (Tables 4 and 5,
Figure 4). This methodology supports the reliability of
the fitting curves used for interpolation of results,
which can be applied to other similar-sized bulk
carriers. The linear and simplistic nature of these
equations makes them useful for preliminary estimates
but not as definitive predictors of structural weight,
marking this as a limitation of the study. The original
weights of the structural subgroups increase with ship
size. As shown in the diagram, the bottom and side
shell plating constitute the largest subgroup (among
the 11 considered) by mass, followed by the inner
bottom and hopper plating subgroup.
Corrosion wastage weight loss for each of
subgroups and ships is given in Table 6. Data shows
large dispersion so authors could not provide reliable
fitting curves. The quantified ship mass loss due to
corrosion, ranging from 0.22% to 0.66% as shown in
Figure 5, spans a wide range but offers a preliminary
sense of the magnitude of corrosion impacts. This
range provides a foundational estimate that can be
used to gauge similar phenomena in comparable ships.
A closer examination of the data reveals that among
all 11 subgroups, across all ships considered, the inner
bottom and hopper platings (8. IBHP) experience the
most significant corrosion wastage over the lifetime of
these four Handymax bulk carriers. The corrosion
wastage in this structural component is several times
greater than that observed in the next most affected
subgroups within the same range (Figure 3), namely:
cargo hold transverse bulkheads (6. CHTB), cargo hold
frames with brackets (5. ISTST), and internal structures
in top-side tanks (7. CHMF). This is expected, as these
ship sections are part of the cargo holds, which
experience significant operational and environmental
variations, including exposure to heavy handling
equipment and high-density cargo, both of which
contribute to accelerated corrosion compared to certain
other bulk cargoes (see Table 1).
Although these components are part of the heavier
structural groups, as shown in Table 4, they do not
represent the heaviest structural elements. The
minimum estimated original weights of subgroups
indicate that the largest components are the bottom
and side shell platings (3. BSSP) and the internal
structures in the double bottom tank (9. ISDBT), which
belong to the lower category of subgroups affected by
corrosion. A direct correlation between the minimum
estimated weight loss due to corrosion and the actual
weight of steel structure replaced is not clearly
established. Nevertheless, Table 6 shows that the
maximum estimated corrosion wastage loss is most
248
pronounced for the inner bottom and hopper platings
(8. IBHP), leading to the conclusion that this structural
component is the most affected by corrosion across all
four ships. This can be attributed to the frequent
loading and unloading cycles and the application of
heavy manipulative equipment, to which this section is
exposed, making it particularly susceptible to
corrosion.
Nevertheless, the study faces inherent limitations
due to the small sample size of just four bulk carriers,
which restricts the generalizability of the predictions
and the reliability of the ship weight estimations. The
scarcity and inaccessibility of weight data, which
shipyards, ship operators, classification societies, and
surveyors typically do not disclose publicly,
compound these limitations. Despite these constraints,
the data presented can significantly contribute to
preliminary designs or early assessments of corrosion-
induced structural loss in bulk carriers of this class.
Moreover, the similarity in structural and
dimensional features of the single-skin bulk carriers
studied here lends credibility to the findings,
suggesting that they may be representative of similar
vessels.
An additional limitation is the lack of specific on-
site criteria for the renewal of structural members,
leading to reliance on assumptions in the analysis.
Given that renewal decisions often depend on
corrosion exceeding 20% or 30% of original thickness,
the estimated corrosion-induced weight loss presented
might be underrepresented, as our analysis assumes a
minimum of 20% degradation without precise
knowledge of the actual conditions.
In summary, while the study's limitations restrict its
ability to provide definitive predictions, the findings
offer valuable insights into corrosion patterns and their
implications for ship maintenance and design
strategies. This underscores the need for more
extensive data collection and sharing within the
maritime industry to enhance the accuracy and
applicability of future research.
5 CONCLUSIONS
This research has analyzed corrosion-induced steel
replacement in four Handymax-class bulk carriers,
providing a detailed assessment of corrosion impacts
across various structural subgroups. The assessment is
based on an actual from shipyards data presented here,
for ships monitored during their lifespan of 25 years.
This makes one of the main contributions of the paper.
The study documents substantial variability in steel
replacement across the structural subgroups. This can
be understandable given the complex nature of
corrosion occurrence, such as environmental exposure,
operational factors, and maintenance practices. In that
context, inner bottom and hopper platings shows the
most dominant corrosion loss of all subgroups. This
can be attributed to the frequent loading and
unloading cycles to which this section is exposed, as
well as the use of heavy manipulative equipment for
such particular type of bulk cargo.
Although the data provided useful insights for
estimating the extent of corrosion-related losses, the
significant variability noted limits the applicability of
these findings as universal predictors. The linear
regression models derived from the data of similar
ships serve as preliminary tools for estimating
potential steel loss but should be applied cautiously,
considering their limitations in prediction accuracy.
The limited sample size and the unavailability of
comprehensive weight and corrosion data restrict the
generalizability of the findings. Future research should
aim to include a larger dataset and collaborate closely
with shipyards, classification societies, and operators
to obtain more detailed operational and maintenance
data. This would enhance the robustness of predictive
models and the reliability of corrosion impact
assessments.
The insights provided represent a significant
advancement in understanding corrosion processes
within ship structures. These results pave the way for
more informed decisions in ship design, maintenance,
and operational strategies, which are crucial for
enhancing the safety and longevity of maritime assets.
The findings underscore the necessity for ship
designers and operators to consider enhanced
corrosion protection strategies, and monitoring [42],
particularly in highly susceptible areas. Adoption of
improved design features and materials could mitigate
corrosion risks and extend the service life of ship
structures.
ACKNOWLEDGEMENT
This research is supported by the approved thickness
measurement company - INVAR-Ivošević Company. More
information about the company can be found at URL:
http://www.invar.me/index.html. The data are collected and
systematized during the lifetime of ships by the company
operators and experts, and thus, used here for the analysis.
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