Saran Rolling Motion of a Round Bottom Ship (Scale Model) in Different Free Surfaces of a Liquid Cargo
DAFTAR PUSTAKA
Bhattacharyya R. 1978. Dynamics of Marine Vehicles. John Wiley Sons, Inc. New York.
Fyson J. 1985. Design of Small Fishing Vessel. England: Fishing News Book Ltd. Hind J A. 1982. Stability and Trim of Fishing Vessels. Second edition. Fishing
News Books Ltd. Farnham, England. Lee S K, Surenndran S and Lee G. 2005. Roll Performance of Small Fishing
Vessel with Live Fish Tank. Ocean Engineering 32 2005: 1873-1885. Lewis E V. 1988. Principles of Naval Architecture. Second Revision, Volume I
Stability and Strength. Jersey City, New York: The Society of Naval Architects and Marine Engineers.
Liliana N, Novita Y dan Purwangka F. 2012. Jenis Muatan dan Pengaruhnya terhadap Rolling Period Model Kapal. Buletin Pemanfaatan Sumberdaya
Perikanan Vol. XX No. 3 hal. 249-260. Marjoni. 2009. Stabilitas Statis dan Dinamis Kapal Purse Seine di Pelabuhan
Perikanan Pantai Lampulo Kota Banda Aceh Naggroe Aceh Darussalam [Tesis]. Bogor: Fakultas Perikanan dan Ilmu Kelautan, Institut Pertanian
Bogor.
Nomura M. and Yamazaki T. 1977. Fishing Techniques I. Tokyo: Japan International Cooperation Agency.
Novita Y, Iskandar BH, Murdiyanto B, Wiryawan B dan Hariyanto. 2010. Keragaan Free Surface pada Model Palka Berbentuk Kotak dan Silinder.
Jurnal Marine Fisheries: Jurnal Teknologi dan Manajemen Perikanan Laut. Vol. I No. 2 Edisi November 2010.
Novita Y. 2011. Desain Palka Kapal Pegangkut Ikan Ditinjau dari Aspek Ketahanan Hidup dan Mitigasi Risiko [Disertasi]. Bogor: Fakultas
Perikanan dan Ilmu Kelautan, Instutut Pertanian Bogor. Novita Y. 2011. Pengaruh Free Surface terhadap Stabilitas Statis Kapal
Pengangkut Ikan Hidup. Buletin Departemen Pemanfaatan Sumberdaya Perikanan. Vol. XIX No. 2 Edisi Juli 2011.
Saputra D. 2007. Kajian Ukuran dan Posisi Pemasangan Bilge Keel Pada Kasko Model Kapal Bentuk Round Bottom Terhadap Tahanan Gerak [Skripsi].
Bogor: Program Studi Pemanfaatan Sumberdaya Perikanan, Fakultas Perikanan dan Ilmu Kelautan, Institut Pertanian Bogor.
Taylor LG. 1977. The Principels and Practices of Stability. Glasgow: Brow Son Publisher Ltd., Nautical Publisher.
LAMPIRAN
Lampiran 1 Dokumentasi penelitian
Kolam percobaan Pemasangan whiteboard di kolam
Penempatan muatan ke dalam model Penempatan model kapal
Menggerakkan model kapal Pergerakan muatan cair
Lampiran 2 Uji statistik sudut kemiringan free surface A
1
vs A
2 SUMMARY OUTPUT
Regression Statistics
Multiple R 0.9714668
R Square 0.9437478
Adjusted R Square
0.9390601 Standard
Error 1.8114582
Observations 14
ANOVA
df SS
MS F
Significance F
Regression 1
660.62343 660.62343
201.32482 7.326E-09
Residual 12
39.376571 3.2813809
Total 13
700
Coefficients Standard
Error t Stat
P-value Lower 95
Upper 95
Lower 95.0
Upper 95.0
Intercept 3.5363254
0.8241621 4.2908127
0.0010488 1.7406304
5.3320205 1.7406304
5.3320205
X Variable 1 0.9168958
0.0646207 14.188898
7.326E-09 0.7760995
1.0576921 0.7760995
1.0576921
Lampiran 3 Uji statistik sudut kemiringan free surface A
1
vs A
3 SUMMARY OUTPUT
Regression Statistics
Multiple R 0.9651264
R Square 0.9314689
Adjusted R Square
0.925758 Standard
Error 1.9994115
Observations 14
ANOVA
df SS
MS F
Significance F
Regression 1
652.02824 652.02824
163.10303 2.409E-08
Residual 12
47.971757 3.9976464
Total 13
700
Coefficients Standard
Error t Stat
P-value Lower 95
Upper 95
Lower 95.0
Upper 95.0
Intercept 2.8020213
0.9608186 2.9162854
0.0129292 0.7085774
4.8954652 0.7085774
4.8954652
X Variable 1 1.1241866
0.0880253 12.77118
2.409E-08 0.932396
1.3159772 0.932396
1.3159772
Lampiran 4 Uji statistik sudut kemiringan free surface A
1
vs A
4
SUMMARY OUTPUT
Regression Statistics
Multiple R 0.9820855
R Square 0.9644918
Adjusted R Square
0.9615328 Standard
Error 1.4392045
Observations 14
ANOVA
df SS
MS F
Significance F
Regression 1
675.14429 675.14429
325.95045 4.592E-10
Residual 12
24.855715 2.0713096
Total 13
700
Coefficients Standard
Error t Stat
P-value Lower 95
Upper 95
Lower 95.0
Upper 95.0
Intercept 3.1399533
0.6679959 4.7005581
0.0005138 1.6845154
4.5953913 1.6845154
4.5953913
X Variable 1 1.254915
0.0695086 18.054098
4.592E-10 1.1034688
1.4063613 1.1034688
1.4063613
Lampiran 5 Uji statistik sudut kemiringan free surface A
2
vs A
3
SUMMARY OUTPUT
Regression Statistics
Multiple R 0.9693687
R Square 0.9396756
Adjusted R Square
0.9346486 Standard
Error 2.1948622
Observations 14
ANOVA
df SS
MS F
Significance F
Regression 1
900.49453 900.49453
186.92464 1.116E-08
Residual 12
57.809042 4.8174201
Total 13
958.30357
Coefficients Standard
Error t Stat
P-value Lower 95
Upper 95
Lower 95.0
Upper 95.0
Intercept -3.0335968
1.1082222 -
2.7373543 0.0180194
-5.4482057 -
0.618988 -
5.4482057 -
0.618988
X Variable 1 1.3843874
0.1012568 13.672039
1.116E-08 1.1637677
1.605007 1.1637677
1.605007
Lampiran 6 Uji statistik sudut kemiringan free surface A
2
vs A
4
SUMMARY OUTPUT
Regression Statistics
Multiple R 0.9387639
R Square 0.8812777
Adjusted R Square
0.8713841 Standard
Error 3.3623878
Observations 14
ANOVA
df SS
MS F
Significance F
Regression 1
1007.0643 1007.0643
89.076186 6.666E-07
Residual 12
135.66782 11.305652
Total 13
1142.7321
Coefficients Standard
Error t Stat
P-value Lower 95
Upper 95
Lower 95.0
Upper 95.0
Intercept -3.5065811
1.5606268 -
2.2469056 0.0442432
-6.9068949 -
0.1062674 -
6.9068949 -
0.1062674
X Variable 1 1.5326558
0.1623917 9.4380181
6.666E-07 1.1788347
1.8864769 1.1788347
1.8864769
Lampiran 7 Uji statistik sudut kemiringan free surface A
3
vs A
4 SUMMARY OUTPUT
Regression Statistics
Multiple R 0.9719465
R Square 0.94468
Adjusted R Square
0.94007 Standard
Error 1.7877716
Observations 14
ANOVA
df SS
MS F
Significance F
Regression 1
654.95004 654.95004
204.91988 6.625E-09
Residual 12
38.353528 3.1961273
Total 13
693.30357
Coefficients Standard
Error t Stat
P-value Lower 95
Upper 95
Lower 95.0
Upper 95.0
Intercept -1.8900367
0.8297807 -
2.2777546 0.0418477
-3.6979734 -
0.0820999 -
3.6979734 -
0.0820999
X Variable 1 1.2360047
0.0863432 14.315023
6.625E-09 1.047879
1.4241303 1.047879
1.4241303
Lampiran 8 Uji statistik rolling period A
1
vs A
2 SUMMARY
OUTPUT
Regression Statistics
Multiple R 0.9904776
R Square 0.9810459
Adjusted R Square
0.9783382 Standard
Error 0.0310252
Observations 9
ANOVA
df SS
MS F
Significance F
Regression 1
0.3487509 0.348751
362.314 2.749E-07
Residual 7
0.006738 0.000963
Total 8
0.3554889
Coefficients Standard
Error t Stat
P-value Lower 95
Upper 95 Lower
95.0 Upper
95.0
Intercept 0.1374271
0.0203536 6.751992
0.00026 0.0892986
0.18555568 0.08929859
0.18555568
X Variable 1 0.9212134
0.0483969 19.03455
2.7E-07 0.8067729
1.03565393 0.80677293
1.03565393
Lampiran 9 Uji statistik rolling period A
1
vs A
3 SUMMARY OUTPUT
Regression Statistics
Multiple R 0.9700402
R Square 0.940978
Adjusted R Square
0.9325463 Standard
Error 0.0547484
Observations 9
ANOVA
df SS
MS F
Significance F
Regression 1
0.3345072 0.334507
111.6 1.488E-05
Residual 7
0.0209817 0.002997
Total 8
0.3554889
Coefficients Standard
Error t Stat
P-value Lower 95
Upper 95 Lower
95.0 Upper
95.0
Intercept 0.2066072
0.030983 6.668408
0.00029 0.1333441
0.27987039 0.13334411
0.27987039
X Variable 1 0.9017177
0.085357 10.56408
1.5E-05 0.6998806
1.10355484 0.69988059
1.10355484
Lampiran 10 Uji statistik rolling period A
1
vs A
4 SUMMARY OUTPUT
Regression Statistics Multiple R
0.938595 R Square
0.8809606 Adjusted R
Square 0.863955
Standard Error
0.0777516 Observations
9 ANOVA
df SS
MS F
Significance F
Regression 1
0.3131717 0.313172
51.8041 0.0001778
Residual 7
0.0423172 0.006045
Total 8
0.3554889 Coefficients
Standard Error
t Stat P-value
Lower 95 Upper
95 Lower
95.0 Upper
95.0
Intercept 0.2644681
0.038678 6.83769
0.00024 0.1730092
0.355927 0.17300918
0.355927 X Variable 1
0.8415327 0.1169201
7.197504 0.00018
0.5650606 1.1180047
0.56506062 1.1180047
Lampiran 11 Uji statistik rolling period A
2
vs A
3
SUMMARY OUTPUT
Regression Statistics
Multiple R 0.9872455
R Square 0.9746536
Adjusted R Square
0.9710327 Standard
Error 0.0385751
Observations 9
ANOVA
df SS
MS F
Significance F
Regression 1
0.4005393 0.4005393
269.17323 7.62E-07
Residual 7
0.0104162 0.001488
Total 8
0.4109556
Coefficients Standard
Error t Stat
P-value Lower 95
Upper 95
Lower 95.0
Upper 95.0
Intercept 0.0727867
0.0218303 3.3342105
0.0125186 0.0211663
0.1244071 0.0211663
0.1244071
X Variable 1 0.986712
0.0601415 16.4065
7.62E-07 0.8444999
1.1289242 0.8444999
1.1289242
Lampiran 12 Uji statistik rolling period A
2
vs A
4
SUMMARY OUTPUT
Regression Statistics
Multiple R 0.9485965
R Square 0.8998353
Adjusted R Square
0.885526 Standard
Error 0.0766842
Observations 9
ANOVA
df SS
MS F
Significance F
Regression 1
0.3697923 0.3697923
62.884876 9.641E-05
Residual 7
0.0411633 0.0058805
Total 8
0.4109556
Coefficients Standard
Error t Stat
P-value Lower 95
Upper 95
Lower 95.0
Upper 95.0
Intercept 0.1376746
0.038147 3.6090553
0.008635 0.0474713
0.2278779 0.0474713
0.2278779
X Variable 1 0.9144472
0.1153149 7.9299985
9.641E-05 0.6417708
1.1871237 0.6417708
1.1871237
Lampiran 13 Uji statistik rolling period A
3
vs A
4 SUMMARY OUTPUT
Regression Statistics
Multiple R 0.9791353
R Square 0.958706
Adjusted R Square
0.9528069 Standard
Error 0.0492636
Observations 9
ANOVA
df SS
MS F
Significance F
Regression 1
0.3944117 0.3944117
162.51628 4.233E-06
Residual 7
0.0169883 0.0024269
Total 8
0.4114
Coefficients Standard
Error t Stat
P-value Lower 95
Upper 95
Lower 95.0
Upper 95.0
Intercept 0.0614314
0.0245065 2.5067411
0.0405899 0.0034828
0.11938 0.0034828
0.11938
X Variable 1 0.944397
0.0740809 12.748187
4.233E-06 0.7692235
1.1195704 0.7692235
1.1195704
Lampiran 14 Uji statistik frekuensi rolling model kapal A
1
vs A
2 SUMMARY OUTPUT
Regression Statistics
Multiple R 0.440407
R Square 0.193959
Adjusted R Square
0.093203
Standard Error 0.223425
Observations 10
ANOVA
df SS
MS F
Significance F
Regression 1
0.096096 0.0961
1.925 0.2027
Residual 8
0.39935 0.0499
Total 9
0.495446
Coefficients Standard
Error t Stat
P- value
Lower 95 Upper
95 Lower
95.0 Upper
95.0
Intercept 3.644997
1.113935 3.2722
0.0113 1.0763
6.21374 1.07626
6.2137
X Variable 1 -0.63431
0.457174 -
1.3875 0.2027
-1.6886 0.41993
-1.6886 0.4199
Lampiran 15 Uji statistik frekuensi rolling model kapal A
1
vs A
3 SUMMARY OUTPUT
Regression Statistics
Multiple R 0.127719
R Square 0.016312
Adjusted R Square
-0.10665
Standard Error 0.246821
Observations 10
ANOVA
df SS
MS F
Significance F
Regression 1
0.008082 0.0081
0.1327 0.7251
Residual 8
0.487364 0.0609
Total 9
0.495446
Coefficients Standard
Error t Stat
P- value
Lower 95 Upper
95 Lower
95.0 Upper
95.0
Intercept 1.999801
0.292746 6.8312
0.0001 1.3247
2.67487 1.32473
2.6749
X Variable 1 0.053055
0.145663 0.3642
0.7251 -0.2828
0.38895 -0.2828
0.389
Lampiran 16 Uji statistik frekuensi rolling model kapal A
1
vs A
4 SUMMARY OUTPUT
Regression Statistics
Multiple R 0.213725
R Square 0.045678
Adjusted R Square
-0.07361 Standard Error
0.243109
Observations 10
ANOVA
df SS
MS F
Significance F
Regression 1
0.022631 0.0226
0.3829 0.5533
Residual 8
0.472815 0.0591
Total 9
0.495446
Coefficients Standard
Error t Stat
P- value
Lower 95 Upper
95 Lower
95.0 Upper
95.0
Intercept 2.815757
1.15509 2.4377
0.0407 0.1521
5.4794 0.15211
5.4794
X Variable 1 -0.2483
0.401261 -
0.6188 0.5533
-1.1736 0.67701
-1.1736 0.677
Lampiran 17 Uji statistik frekuensi rolling model kapal A
2
vs A
3
SUMMARY OUTPUT
Regression Statistics
Multiple R 0.3997391
R Square 0.1597913
Adjusted R Square
0.0547652 Standard
Error 0.1583794
Observations 10
ANOVA
df SS
MS F
Significance F
Regression 1
0.0381639 0.0381639
1.5214442 0.2524104
Residual 8
0.2006722 0.025084
Total 9
0.2388361
Coefficients Standard
Error t Stat
P-value Lower 95
Upper 95
Lower 95.0
Upper 95.0
Intercept 1.718202
0.5805791 2.9594622
0.0181611 0.3793841
3.0570198 0.3793841
3.0570198
X Variable 1 0.2918582
0.2366159 1.2334684
0.2524104 -0.253779
0.8374954 -0.253779
0.8374954
Lampiran 18 Uji statistik frekuensi rolling model kapal A
2
vs A
4 SUMMARY OUTPUT
Regression Statistics Multiple R
0.0462543 R Square
0.0021395 Adjusted R
Square -0.1225931
Standard Error
0.1725997 Observations
10
ANOVA df
SS MS
F Significance
F Regression
1 0.000511
0.000511 0.0171524
0.8990349 Residual
8 0.2383251
0.0297906 Total
9 0.2388361
Coefficients Standard
Error t Stat
P-value Lower 95
Upper 95
Lower 95.0
Upper 95.0
Intercept 2.5388235
0.8200782 3.095831
0.0147586 0.6477198
4.4299272 0.6477198
4.4299272 X Variable 1
-0.0373102 0.2848825
- 0.1309671
0.8990349 -0.6942506
0.6196301 -
0.6942506 0.6196301
Lampiran 19 Uji statistik frekuensi rolling model kapal A
3
vs A
4 SUMMARY OUTPUT
Regression Statistics
Multiple R 0.1384466
R Square 0.0191675
Adjusted R Square
-0.1034366 Standard
Error 0.1314534
Observations 10
ANOVA
df SS
MS F
Significance F
Regression 1
0.0027015 0.0027015
0.1563363 0.7028865
Residual 8
0.13824 0.01728
Total 9
0.1409415
Coefficients Standard
Error t Stat
P-value Lower 95
Upper 95
Lower 95.0
Upper 95.0
Intercept 2.915071
0.6245789 4.6672584
0.0016082 1.4747895
4.3553524 1.4747895
4.3553524
X Variable 1 -0.0857882
0.2169691 -
0.3953938 0.7028865
-0.5861198 0.4145434
- 0.5861198
0.4145434
Lampiran 20 Uji statistik waktu redam model kapal A
1
vs A
2 SUMMARY OUTPUT
Regression Statistics
Multiple R 0.4309049
R Square 0.1856791
Adjusted R Square
0.083889 Standard
Error 0.3547997
Observations 10
ANOVA
df SS
MS F
Significance F
Regression 1
0.2296274 0.2296274
1.8241365 0.2137807
Residual 8
1.0070626 0.1258828
Total 9
1.23669
Coefficients Standard
Error t Stat
P-value Lower 95
Upper 95
Lower 95.0
Upper 95.0
Intercept 5.4657134
1.0166552 5.376172
0.0006647 3.1213022
7.8101246 3.1213022
7.8101246
X Variable 1 -0.4766725
0.3529323 -1.350606
0.2137807 -1.2905359
0.3371909 -
1.2905359 0.3371909
Lampiran 21 Uji statistik waktu redam model kapal A
1
vs A
3 SUMMARY OUTPUT
Regression Statistics Multiple R
0.3709388
R Square 0.1375956
Adjusted R Square
0.029795 Standard
Error 0.3651245
Observations 10
ANOVA
df SS
MS F
Significance F
Regression 1
0.1701631 0.1701631
1.2763904 0.2913049
Residual 8
1.0665269 0.1333159
Total 9
1.23669
Coefficients Standard
Error t Stat
P-value Lower 95
Upper 95
Lower 95.0
Upper 95.0
Intercept 5.4173711
1.1708697 4.6267926
0.0016951 2.7173408
8.1174014 2.7173408
8.1174014
X Variable 1 -0.5362001
0.474608 -
1.1297745 0.2913049
-1.6306482 0.558248
- 1.6306482
0.558248
Lampiran 22 Uji statistik waktu redam model kapal A
1
vs A
4
SUMMARY OUTPUT
Regression Statistics
Multiple R 0.3937676
R Square 0.1550529
Adjusted R Square
0.0494345 Standard
Error 0.36141
Observations 10
ANOVA
df SS
MS F
Significance F
Regression 1
0.1917524 0.1917524
1.4680484 0.2602244
Residual 8
1.0449376 0.1306172
Total 9
1.23669
Coefficients Standard
Error t Stat
P-value Lower 95
Upper 95
Lower 95.0
Upper 95.0
Intercept 5.108586
0.8394118 6.0859117
0.000294 3.1728989
7.044273 3.1728989
7.044273
X Variable 1 -0.471275
0.3889594 -
1.2116305 0.2602244
-1.3682169 0.4256669
- 1.3682169
0.4256669
Lampiran 23 Uji statistik waktu redam model kapal A
2
vs A
3 SUMMARY OUTPUT
Regression Statistics
Multiple R 0.0144171
R Square 0.0002079
Adjusted R Square
-0.1247662 Standard
Error 0.3553871
Observations 10
ANOVA
df SS
MS F
Significance F
Regression 1
0.0002101 0.0002101
0.0016632 0.9684692
Residual 8
1.0103999 0.1263
Total 9
1.01061
Coefficients Standard
Error t Stat
P-value Lower 95
Upper 95
Lower 95.0
Upper 95.0
Intercept 2.8167497
1.1396442 2.4716043
0.0386137 0.1887253
5.444774 0.1887253
5.444774
X Variable 1 0.0188392
0.4619509 0.0407819
0.9684692 -1.0464215
1.0841 -
1.0464215 1.0841
Lampiran 24 Uji statistik waktu redam model kapal A
2
vs A
4
SUMMARY OUTPUT
Regression Statistics
Multiple R 0.6598226
R Square 0.4353658
Adjusted R Square
0.3647866 Standard
Error 0.2670732
Observations 10
ANOVA
df SS
MS F
Significance F
Regression 1
0.4399851 0.4399851
6.1684662 0.037896
Residual 8
0.5706249 0.0713281
Total 9
1.01061
Coefficients Standard
Error t Stat
P-value Lower 95
Upper 95
Lower 95.0
Upper 95.0
Intercept 1.3822476
0.6021547 2.2955023
0.0508264 -0.0063237
2.7708189 -
0.0063237 2.7708189
X Variable 1 0.6951889
0.2799073 2.4836397
0.037896 0.0497215
1.3406564 0.0497215
1.3406564
Lampiran 25 Uji statistik waktu redam model kapal A
3
vs A
4 SUMMARY OUTPUT
Regression Statistics
Multiple R 0.3561694
R Square 0.1268566
Adjusted R Square
0.0177137 Standard
Error 0.2541579
Observations 10
ANOVA
df SS
MS F
Significance F
Regression 1
0.0750801 0.0750801
1.1622984 0.3124204
Residual 8
0.5167699 0.0645962
Total 9
0.59185
Coefficients Standard
Error t Stat
P-value Lower 95
Upper 95
Lower 95.0
Upper 95.0
Intercept 3.0854842
0.5903077 5.2269078
0.0007959 1.724232
4.4467363 1.724232
4.4467363
X Variable 1 -0.2948944
0.2735317 -
1.0780995 0.3124204
-0.9256596 0.3358708
- 0.9256596
0.3358708
ABSTRAK
ARIESTIO DWI RAMADHAN, C44080066. Keragaan Oleng Kapal Round
Bottom Skala Model dengan Luas Free Surface Muatan Cair yang Berbeda. Dibimbing oleh YOPI NOVITA dan MOHAMMAD IMRON.
Kapal pengangkut ikan hidup adalah kapal yang khusus digunakan untuk mengangkut ikan dalam kondisi hidup dengan muatan utamanya adalah air dan
ikan. Jenis muatan kapal ini dikategorikan sebagai jenis muatan cair. Sifat muatan cair berubah bentuk sesuai wadahnya, sehingga titik beratnya selalu
bergeser. Kondisi ini dikarenakan muatan cair memiliki free surface. Free surface berdampak terhadap kestabilan kapal. Pergeseran titik berat muatan
menyebabkan kapal bermuatan cair menjadi berkurang kestabilannya dibandingkan kapal bermuatan padat. Tujuan penelitian ini adalah : 1
menentukan parameter keragaan oleng model kapal yang dipengaruhi luasan free surface, dan 2 menentukan pengaruh luas free surface terhadap keragaan oleng
model kapal. Metode penelitian dilakukan dengan mengamati gerakan rolling model kapal sebagai efek dari keberadaan palka dengan beberapa perlakuan
berbeda dan pergerakan free surface-nya. Berdasarkan hasil penelitian dapat disimpulkan bahwa luas free surface memberikan pengaruh terhadap keragaan
oleng kapal, dimana semakin luas free surface maka nilai sudut kemiringan, nilai rolling period, dan nilai waktu redam semakin besar, sedangkan untuk nilai
frekuensinya semakin mengecil. Kata kunci : free surface, rolling period, stabilitas
ABSTRACT
ARIESTIO DWI RAMADHAN, C44080066. Rolling Motion of a Round Bottom Ship Scale Model in Different Free Surfaces of a Liquid Cargo.
Supervised by YOPI NOVITA and MOHAMMAD IMRON.
L ive fish carrier is a common termininology in a carrier or ship which is used to
transport live fish from one place to another. The cargoes which mostly consists of water is classified as a liquid cargo. Based on its characteristic, a liquid cargo
will always follow the shape of its containers and maintain its flat surface. As a result, position of the centre of gravity in the containers will change easily
depending on their movements. Furthermore, it is known that a liquid cargo has free surface which may influences ship stability. Therefore, comparing to solid
cargo, a liquid cargo has more negative effects on ship stability. The objectives of this research were, 1 to determine rolling performance parameter influenced by
free surface, and 2 to determine the influence of free surface on rolling performance of a ship model. Experimental method was applied in this research
by using a ship model. Observation was carried out in order to record the rolling performance of the model as an effect of some variations of fish hold condition
and free surface. Based on the result, it can be concluded that the wide of free surface gives impact on ship motions, where the extending of free surface will be
followed by the increasing of inclination angle, rolling period, and attenuation time. However, at the same time the frequency of rolling is getting smaller.
Keywords: free surface, rolling period, stability
1 PENDAHULUAN