Floating breakwaters (FBWs) are widely used in moderate wave climatic conditions for coastal protection against erosion and for wave reduction around offshore loading terminals and open ocean construction sites. Literature shows that the width of a pontoon-type FBW is about 50% of the incident wavelength in order to achieve 50% wave height reduction at the lee side of the FBW. Hence, for a typical wavelength of 40 m, the width needed for pontoon FBW is about 20 m. Such an FBW may not be cost competitive. Is it possible to reduce the width of the pontoon FBW significantly by adding skirt walls (single, twin, triple, or five) at its keel. What will be the effect on mooring forces? In order to find solutions for these problems, experimental investigations were carried out on a typical pontoon-type FBW as well as pontoon with skirt walls. Both opaque and porous skirt walls were used. Wave transmission, reflection, and mooring forces, both on the sea side and lee side, were measured. It was found from this study that it is possible to reduce the width by 20 to 40% by introducing three or five skirt walls. However, introducing skirt walls increased the mooring forces by 10 to 30%. The results of this study are expected to be useful for cost-effective design of FBWs.

References

References
1.
Yamamoto
,
T.
,
Yoshida
,
A.
, and
Ijima
,
T.
,
1980
, “
Dynamics of Elastically Moored Floating Objects
,”
Appl. Ocean Res.
,
2
(
2
), pp.
85
92
.
2.
Stiassnie
,
M.
,
1980
, “
A Simple Mathematical Model of a Floating Breakwater
,”
Appl. Ocean Res.
,
2
(
3
), pp.
107
111
.
3.
Yamamoto
,
T.
,
1981
, “
Moored Floating Breakwater Response to Regular and Irregular Waves
,”
Appl. Ocean Res.
,
3
(
1
), pp.
27
36
.
4.
Hanif
,
M.
,
1983
, “
Analysis of Heaving and Swaying Motion of a Floating Breakwater by Finite Element Method
,”
Ocean Eng.
,
10
(
3
), pp.
181
190
.
5.
Georgiadis
,
C.
,
1983
, “
CGFLOAT (a Computer Program for the Dynamic Analysis of Floating Bridges and Breakwaters)
,”
Adv. Eng. Software
,
5
(
4
), pp.
215
220
.
6.
Leach
,
P. A.
,
McDougal
,
W. G.
, and
Sollitt
,
C. K.
,
1985
, “
Hinged Floating Breakwater
,”
J. Waterw., Port, Coastal, Ocean Eng.
,
111
(
5
), pp.
895
909
.
7.
Williams
,
A. N.
,
1985
, “
Wave Diffraction by Elliptical Breakwaters in Shallow Water
,”
Ocean Eng.
,
12
(
1
), pp.
25
43
.
8.
Drimer
,
N.
,
Agnon
,
Y.
, and
Stiassnie
,
M.
,
1992
, “
A Simplified Analytical Model for a Floating Breakwater in Water of Finite Depth
,”
Appl. Ocean Res.
,
14
(
1
), pp.
33
41
.
9.
Abul-Azm
,
A. G.
,
1994
, “
Wave Diffraction by Double Flexible Breakwaters
,”
Appl. Ocean Res.
,
16
(
2
), pp.
87
99
.
10.
Abul-Azm
,
A. G.
,
1996
, “
Wave Diffraction Through Submerged Flexible Breakwaters
,”
Ocean Eng.
,
23
(
5
), pp.
403
422
.
11.
Ren
,
X.
, and
Wang
,
K. H.
,
1994
, “
Mooring Lines Connected to Floating Porous Breakwaters
,”
Int. J. Eng. Sci.
,
32
(
10
), pp.
1511
1530
.
12.
Lee
,
C. P.
, and
Ker
,
W. K.
,
2002
, “
Coupling of Linear Waves and a Hybrid Porous TLP
,”
Ocean Eng.
,
29
(9), pp.
1049
1066
.
13.
Stiassnie
,
M.
, and
Drimer
,
N.
,
2003
, “
On a Freely Floating Porous Box in Shallow Water Waves
,”
Appl. Ocean Res.
,
25
(
5
), pp.
263
268
.
14.
Gesraha
,
M. R.
,
2006
, “
Analysis of Π Shaped Floating Breakwater in Oblique Waves—I: Impervious Rigid Wave Boards
,”
Appl. Ocean Res.
,
28
(5), pp.
327
338
.
15.
Rahman
,
M. A.
,
Mizutani
,
N.
, and
Kawasaki
,
K.
,
2006
, “
Numerical Modeling of Dynamic Responses and Mooring Forces of Submerged Floating Breakwater
,”
Coastal Eng.
,
53
(10), pp.
799
815
.
16.
Arunachalam
,
V. M.
, and
Raman
,
H.
,
1982
, “
Experimental Studies on a Perforated Horizontal Floating Plate Breakwater
,”
Ocean Eng.
,
9
(
1
), pp.
35
45
.
17.
McCartney
,
B. L.
,
1985
, “
Floating Breakwater Design
,”
J. Waterw., Port, Coastal, Ocean Eng.
,
111
(
2
), pp.
304
318
.
18.
Murali
,
K.
, and
Mani
,
J. S.
,
1997
, “
Performance of Cage Floating Breakwater
,”
J. Waterw., Port, Coastal, Ocean Eng.
,
123
(
4
), pp.
172
179
.
19.
Rapaka
,
E. V.
,
Natarajan
,
R.
, and
Neelamani
,
S.
,
2004
, “
Experimental Investigation on the Dynamic Response of a Moored Wave Energy Device Under Regular Sea Waves
,”
Ocean Eng.
,
31
(
5–6
), pp.
725
743
.
20.
Günaydin
,
K.
, and
Kabdaşli
,
M. S.
,
2007
, “
Investigation of Π-Type Breakwaters Performance Under Regular and Irregular Waves
,”
Ocean Eng.
,
34
(
7
), pp.
1028
1043
.
21.
Elchahal
,
G.
,
Younes
,
R.
, and
Lafon
,
P.
,
2008
, “
The Effects of Reflection Coefficient of the Harbor Sidewall on the Performance of Floating Breakwaters
,”
Ocean Eng.
,
35
(11–12), pp.
1102
1112
.
22.
Danish Hydraulic Institute,
2004
, “
Wave Synthesizer Software
,” Danish Hydraulic Institute, Hørsholm, Denmark.
23.
Neelamani
,
S.
,
Al-Banaa
,
K.
,
Al-Shatti
,
F.
,
Al-Khaldi
,
M.
, and
Ljubic
,
J.
,
2013
, “
Development of a Feasible Prototype Floating Breakwater for Kuwaiti Marine Conditions
,” Kuwait Institute for Scientific Research, Shuwaikh, Kuwait, Final Report No. KISR 11669.
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