Miscelleneous

C L DUBEY – EXERCISE – 11 (Grain Stability)

Hence, vessel satisfy intact stability requirement for grain cargo or grain loading criteria.
Q3. The values of GZ vessel for various angles of heel are as follows:
Heel (0)
00
05
12
20
30
40
60
75
GZ (m)
0.000
0.136
0.315
0.472
0.604
0.631
0.562
0.248
The heeling arm at 00 = 0.18m. The angle of flooding is 400 and maximum difference between the righting arm and heeling arm occurs at 430. Verify whether the vessel satisfied the criteria of stability for a cargo ship carrying grain in bulk (Assume the deck edge immerses at 100  heel).
Solution –

Given, λ0 = 0.18m, λ40 = 0.14m

GS03

List OrdinateSMProduct
00.010
100.26341.052
200.47220.944
300.60442.416
400.63110.631
   SOP = 5.043

Area = 10/3 ⨯ 5.043/57.3
= 0.293 m radian

Area of triangle = 0.5 ⨯ 6.5 ⨯ 0.1735/57.3
= 0.010m radian

Area of trapezium = 0.5 ⨯ (0.1735 + 0.14) ⨯ (4.0 – 6.5)/57.3
= 0.191m radian

Residual area = 0.192m > 0.075m radian
Therefore, All condition satisfied.

Hence, vessel satisfy intact stability requirement for grain cargo or grain loading criteria.
 
Q4. A vessel loaded with grain in bulk is at a displacement of 35186t, KG 7.809m, KM 11.30m. The stowage factor of the grain is 1.3m3/t and the total volumetric heeling Moments are 21321 m4. AT the displacement her KN values are as follows:
Heel (0)
5
12
15
30
45
60
GZ (m)
1.00
2.42
2.90
5.60
7.30
8.05
If her angle of flooding exceeds 400, ascertain whether the vessel complies with the intact stability requirements for such vessels.
Solution –

Given, KM = 11.30
KG = 7.809m

GM = (KM – KG)
        = 3.491m > 0.3m

Therefore, Condition 1 satisfied

Now total volumetric heeling moment = 21321
Weight heeling moment = VHM/SF
= 16400.7692

Heeling arm = λ0 = 16400.76923/35186
= 0.466m
λ40 = 0.373m

About the author

Manish Mayank

Graduated from M.E.R.I. (Mumbai). A cool, calm, composed and the brain behind the development of the database. The strong will to contribute in maritime education and to present it in completely different and innovative way is his source of inspiration.

Leave a Comment

error: Content is protected !!