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8. LWT
Dimana :
LWT = Wstr + WstAD + Wo + Wm + Wr
Wstr = Weight of steel hull
Menurut Watson and Gilfillan ( 1977 ):
Wst = Cb2/3 . 1/6 L . B . D0.72 . (0.002(L/D)2 + 1)
= 0,7242/3 . 1/6. 9,22 . 70.72 (0,002 (90,22/7)2 + 1)
= 1134.2 ton
WstAD = Weight of steel superstructure and deckhouses
Forecastle
Volume Forcastle dengan luasan forcastle dianggap sebagai luasan segitiga
V = 1/3 . B . L . T . Cforecastle
Dimana = B : Lebar max forecastle
= L : Panjang forecastle
= T : Tinggi forecastle
= Cforecastle : 0,13 ton/m3
V = 1/3 . B . L . T . Cforecastle
= 1/3 . 7,34. 7,54 . 2,4 . 0,13
= 5,75 ton
Poopdeck
Volume Poopdeck dihitung dengan luasan Poopdeck dianggap sebagai luasan jajar genjang
V = ½ . (B1 + B2) . L . T . Cpoopdeck
Dimana = B1 : Lebar bagian belakang poopdeck
= B2 : Lebar bagian depan poopdeck
= L : Panjang poopdeck
= T : Tinggi poopdeck
= Cpoopdeck : 0,075 ton/m3
V = ½ . ( 14,68 + 17,3 ) . 24,09 . 2,4 . 0,075
= 71,66 ton
Deckhouses
Penentuan nilai F0/Fu
F0 = Area real deckhouses ditambah dengan area jalan orang di kiri dan kanan
Deckhouses (294,1m2)
Fu = Area real deckhouses diaasumsikan luas area maksimal (260,1 m2)
F0/Fu = 1,13 dibulatkan 1,0
- Boat deck
Gdh = Cdh . Fu .h . K1 . K2 . K3
Dimana = Cdh : 0,057 ton/m3
= Fu : 260,1
= h : 2,4
= K1 : 1 + 0,02(h – 2,6) = 0,996
= K2 : 1 + 0,05(4,5 – f1) dimna f1 = panjang deck (17)
: 0,375
= K3 : hanya untuk 100 m ≤ Lpp ≤ 230 m
Jadi Gdh = 13,29 ton
- Lower Bridge deck
Gdh = Cdh . Fu .h . K1 . K2 . K3
Dimana = Cdh : 0,063 ton/m3
= Fu : 198,9
= h : 2,4
= K1 : 1 + 0,02(h – 2,6) = 0,996
= K2 : 1 + 0,05(4,5 – f1) dimna f1 = panjang deck (13)
: 0,575
= K3 : hanya untuk 100 m ≤ Lpp ≤ 230 m
Jadi Gdh = 17,2 ton
- Upper Bridge deck
Gdh = Cdh . Fu .h . K1 . K2 . K3
Dimana = Cdh : 0,059 ton/m3
= Fu : 168,3
= h : 2,4
= K1 : 1 + 0,02(h – 2,6) = 0,996
= K2 : 1 + 0,05(4,5 – f1) dimna f1 = panjang deck (11)
: 0,675
= K3 : hanya untuk 100 m ≤ Lpp ≤ 230 m
Jadi Gdh = 16 ton
- Navigation deck
Gdh = Cdh . Fu .h . K1 . K2 . K3
Dimana = Cdh : 0,060 ton/m3
= Fu : 137,7
= h : 2,4
= K1 : 1 + 0,02(h – 2,6) = 0,996
= K2 : 1 + 0,05(4,5 – f1) dimna f1 = panjang deck (9)
: 0,775
= K3 : hanya untuk 100 m ≤ Lpp ≤ 230 m
Jadi Gdh = 15,3 ton
Berat Konstruksi deckhouses = Boat + low bridge + up bridge + navigation
= 65,37 ton
Jadi berat WstAd = berat ( forecastle + poopdeck + deckhouses )
= 142,78 ton
Wo = Weight of equipment and outfit
Wo = 0,40 . 90,22 . 17,3
= 624,32 ton
Wm = Weight of engine
Rpm = 161 KW = 2205
Wm = 0,012t/KW . 2205
= 26,5 ton
Jadi LWT =berat(WsTr + WstAd + Wo + Wm)
= 1927,8 ton
Lwt total = Lwt + berat cadangan ( 3% lwt )
= 1927,8 + ( 1927,8 . 3% )
= 1985,63 ton
Dwt = ∆ - Lwt
= 6961,22 - 1985,63
= 4975,59 ton
