Q5. A vessel of L = 140m, CF = 2m FWd of midship, KM = 6.1m, KG = 5.5m, MCTC = 130 mt, w = 5700t at a draft of F = 4.15m, grounds on a rpck 10 mts for’d of her stern. The tide then falls 80cm. Calculate her virtual GM then and her draft f & A, TPC = 16.
Solution –
We can calculate fall in tide –
Fall in tide = P/ TPC + ( P x AL / MCTC) + AL/ LBP
80 =P/15 + P ⨯ 58/130 ⨯ 58/140
P = 323.44 tonnes
GG1 = 0.346m
GM = 0.254m
Rise = P/ TPC ⨯ 100
= 0.202m
Trim caused = 323.44 ⨯ 58/130 ⨯ 100
= 144m
Ta = 0.701m,
Tf = ( Tc – Ta)
= 0.739m
| Fwd | Aft | |
| Draft | 4.15m | 4.851m |
| Rise | -0.202m | -0.202m |
| +0.739m | -0.701m | |
| 4.687m | 3.948m |
Q6. Vessel of length 120m, LCF = 2m, Aft of midship, Draft = 4.70m. For’d = 5.20 m, Aft TPC = 15 t, MCTC = 110 tm, KM = 5.9, KG = 5.1 m. Grounds on a rock 10 meters abaft her stern. The tide then falls 80cm. Calculate the drafts F & A then and state whether she would remain upright.
Solution –
Not possible to calculate displacement not given.
