stability report “m.y. jetten 45’ beach” - boot.de · section 6.6: seaworthiness it is...
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15-226-312-011 - Stability ISO 12217 - Update Air Inlet Position Stability report “M.Y. Jetten 45’ Beach” Page | 2
15 December 2015
Ordered by:
Jetten Yachting b.v.
Hendrik Bulthuisweg 23
8606 KB Sneek
Author(s):
A. Andreoli
T. Maas Geesteranus, B. Eng.
Van Oossanen Naval Architects b.v.
Costerweg 1B
6702 AA, Wageningen
The Netherlands
www.oossanen.nl
Approved by:
Ir. Niels Moerke
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CONTENTS
INTRODUCTION ................................................................................................................................................ 7
1. GENERAL ARRANGEMENT ........................................................................................................................ 8
2. DESIGN FEATURES .................................................................................................................................... 9
2.1 MAIN PARTICULARS ..................................................................................................................................... 9 2.2 WEIGHTS AND LOAD CONDITIONS ................................................................................................................... 9 2.3 DOWNFLOODING POINTS ............................................................................................................................ 10
3. ISO 12217-1 REQUIREMENTS ................................................................................................................. 11
3.1 INTRODUCTION ......................................................................................................................................... 11 3.2 PARAGRAPH 6.2.1 DOWNFLOODING POINTS .................................................................................................. 11 3.3 PARAGRAPH 6.1.2 DOWNFLOODING POINTS HEIGHT TEST ................................................................................. 12 3.4 PARAGRAPH 6.2 OFFSET-LOAD TEST ............................................................................................................. 14 3.5 PARAGRAPH 6.3 RESISTANCE AGAINST WIND AND WAVES ................................................................................. 16 3.6 PARAGRAPH 6.6 SEAWORTHINESS ................................................................................................................ 24
4. CONCLUSION ......................................................................................................................................... 25
REFERENCES ................................................................................................................................................... 27
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LIST OF FIGURES
FIGURE 1.1 GENERAL ARRANGEMENT M.Y. JETTEN 45 BEACH ....................................................................................... 8 FIGURE 3.1 MINIMAL FREEBOARD HEIGHT FOR CATEGORY A AND CATEGORY B YACHTS ..................................................... 12 FIGURE 3.2 CURVE OF RIGHTING MOMENTS – LC1 ..................................................................................................... 15 FIGURE 3.3 CURVE OF RIGHTING MOMENTS – LC2 ..................................................................................................... 15 FIGURE 3.4 RIGHTING MOMENT AND WIND MOMENT CRITERIA. .................................................................................... 17
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LIST OF TABLES
TABLE 2.1 DATA ASSOCIATED WITH THE “LIGHTSHIP CONDITION” ................................................................................... 9 TABLE 2.2 DATA ASSOCIATED WITH THE “MAXIMUM LOAD” ......................................................................................... 9 TABLE 2.3 DATA ASSOCIATED WITH THE “MINIMUM OPERATING CONDITION” ................................................................ 10 TABLE 2.4 DATA ASSOCIATED WITH THE “LOADED ARRIVAL CONDITION” ........................................................................ 10 TABLE 2.5 COORDINATES OF THE INITIAL DOWNFLOODING POINTS OF THE YACHTS, RELATIVE TO THE ZEROPOINT. .................. 10 TABLE 3.1 HEIGHT OF THE DOWNFLOODING POINTS IN THE MML CONDITION. ................................................................. 12 TABLE 3.2 MINIMUM DOWNFLOODING ANGLES ........................................................................................................ 13 TABLE 3.3 DOWNFLOODING ANGLE CHECK ............................................................................................................... 13 TABLE 3.4 OFFSET LOAD RESULT OVERVIEW ............................................................................................................. 14 TABLE 3.5 DATA ASSOCIATED WITH THE “MINIMUM OPERATING CONDITION” ............................................................... 16 TABLE 3.6 DATA ASSOCIATED WITH THE ARRIVAL LOAD CONDITION .............................................................................. 16 TABLE 3.7 WIND HEELING ARM CALCULATION – MINIMAL OPERATING CONDITION ......................................................... 18 TABLE 3.8 ROLLING IN BEAM WAVES AND WIND – MINIMAL OPERATING CONDITION ....................................................... 19 TABLE 3.9 RESISTANCE TO WAVES – GZ VALUE – MINIMAL OPERATING CONDITION ........................................................ 20 TABLE 3.10 RESISTANCE TO WAVES – RM VALUE – MINIMAL OPERATING CONDITION ....................................................... 20 TABLE 3.11 WIND HEELING ARM CALCULATION – ARRIVAL LOAD CONDITION ................................................................... 21 TABLE 3.12 ROLLING IN BEAM WAVES AND WIND – ARRIVAL LOAD CONDITION ................................................................ 22 TABLE 3.13 RESISTANCE TO WAVES – GZ VALUE - ARRIVAL LOAD CONDITION .................................................................. 23 TABLE 3.14 RESISTANCE TO WAVES – RM VALUE - ARRIVAL LOAD CONDITION ................................................................. 23
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INTRODUCTION
Part of the design of the MY Jetten 45 Beach is to validate the stability in accordance with the requirements of ISO 12217-1. This report presents the results of the stability calculations. The MY Jetten 45 Beach will be assessed to the requirements for category A (ocean) as defined in the ISO standard, where possible. If it does not make the requirements that are set for category A, an assessment of category B will be executed The weight and the location of the centre of gravity are calculated based on a detailed weight calculation. The hull and appendages are modelled in 3D with the program MAXSURF. This 3D model will be used in the program HYDROMAX for the assessment of the hydrostatics and stability characteristics of the vessel. In accordance with Appendix C of the ISO standard, the location of the centre of gravity is increased by 5% of (IM + TC), when a calculation method is used for the determination of the vertical centre of gravity (VCG) instead of an experimental determination by means of an inclining test, were FM is the freeboard amidships, and TC is the canoe body draft. The MY Jetten 45 Beach has been assessed with respect to the following requirements: ISO 12217-1, option 1, Table 2, Design Category A and B : Section 6.1.1: Downflooding points Section 6.1.2: Downflooding points height test Section 6.2: Offset-load test Section 6.3: Resistance to wind and waves Section 6.5: Reses size Section 6.6: Seaworthiness It is assumed that the hatches and doors on the deck are all closed, watertight and all comply with ISO 12216. Besides that, the requirements of section 6.5 are taken into account during the design process.
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1. GENERAL ARRANGEMENT
The general arrangement of the M.Y. Jetten 45’ Beach is shown in Figure 1.1.
Figure 1.1 General arrangement M.Y. Jetten 45 Beach
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2. DESIGN FEATURES
2.1 MAIN PARTICULARS
This section states the hull’s main particulars and its dimensions, in design condition. These properties are required for the further stability calculations. ISO 8666:
Length of hull, LH = 13.50 m
Waterline Length, LWL = 13.20 m
Width of the hull, BH = 4.50 m
Waterline Width, BWL = 4.00 m
Max. depth, TMAX = 0.925 m
Draft of hull, TC = 0.919 m
Freeboard amidships, FM = 1.478 m
2.2 WEIGHTS AND LOAD CONDITIONS
From the weight calculation follows: For the "Light craft condition" (MLCC); which is comparable with the “Light Ship Weight” according to ISO 8666, paragraph 6.3:
Table 2.1 Data associated with the “Lightship condition”
Displacement, kg LCG, m VCG, m TCG, m
16036.0 5.830 1.875 0.000
For the “Maximum Load condition” (MML) according to ISO 8666, paragraph 3.5.1:
Table 2.2 Data associated with the “Maximum load”
Displacement, kg LCG, m VCG, m TCG, m
18355.0 5.780 1.753 0.000
The zero point is located vertically at the design waterline, longitudinally at the intersection of the aft ship with this waterline and transversally at the centreline of the yacht. All stability calculations are based on a previously assessed centre of gravity. Although the VCG calculation is based on a long iteration of all various masses in the vessel some assumptions may remain, hence an extra “safety margin” is added to the total VCG equivalent to 5% of (FM+TC).This is in accordance to Appendix C of ISO 12217-1. This margin is calculated: 0.05 x (1.478 + 0.919) = 0.120 m. However, in common practise, we add an additional safety margin on the Light Ship Weight’s VCG, which in this case is 0.250 m. This margin is added to the calculated VCG in the Light Ship Weight and then used in the various loading conditions. During this calculation two other load conditions are taken into consideration:
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A “Minimum operating condition” (MMOC);
Table 2.3 Data associated with the “Minimum operating condition”
Displacement, kg LCG, m VCG, m TCG, m
16322.4 5.829 1.884 0.000
A “Loaded arrival condition” (MLAC);
Table 2.4 Data associated with the “Loaded arrival condition”
Displacement, kg LCG, m VCG, m TCG, m
16797.9 5.879 1.861 0.000
Furthermore, in paragraph 3.4 of this report, the Maximum load condition is used; with an alteration to the LCG and TCG positions.
2.3 DOWNFLOODING POINTS
The following downflooding points are defined:
Table 2.5 Coordinates of the initial downflooding points of the yachts, relative to the zeropoint.
Name Length with respect to
the zero point Breadth with respect to
the zero point Height with respect to
the zero point
ER ventilation PS 1.800 -2.170 2.300
ER ventilation SB 1.800 2.170 2.300
Salon entry 3.870 0.000 1.750
The zero point is located vertically at the design waterline, longitudinally at the intersection of the aft ship with this waterline and transversally at the centreline of the yacht.
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3. ISO 12217-1 REQUIREMENTS
3.1 INTRODUCTION
In order to validate whether the MY Jetten 45 Beach will comply with the requirements set by:
ISO 12217-1 - Stability and buoyancy assessment and categorization Part-1 non-sailing boats of hull length greater than or equal to 6m.
The relevant standards are to be used; those requirements are define as per the following paragraph.
3.2 PARAGRAPH 6.2.1 DOWNFLOODING POINTS
It is assumed here that the builder will comply with the requirements for the downflooding points, as described in this section, namely:
6.1.1.1
All closing appliances fitted to windows, port lights, hatches, deadlights and doors shall comply with ISO 12216, according to design category and appliance location area.
6.1.1.2
No hatches or opening type windows shall be fitted in the hull with the lowest part of the opening less than 0,2 m above the loaded waterline.
6.1.1.3
Seacocks complying with ISO 9093 together with means of preventing flow into the boat shall be fitted to through-hull fittings located with any part of the opening below the loaded waterline when the boat is upright, or through-hull openings that are below the heeled waterline when fully loaded
when the boat is heeled 7, apart from:
a) Drains forming an integral part of the hull or of equal strength and tightness extending from the outlet to at least the heeled waterline defined above, or
b) Cockpit drains complying with ISO 11812.
Means of preventing flow into the boat may comprise:
a pipe or hose extending above the heeled waterline, or
a pipe or hose leading to a down-flooding point above the heeled waterline
a non-return valve, or
a pipe or hose connected to a system that cannot flood the interior of the boat, or
for seacocks not connected internally, a permanent cap or means of securing the seacock in the closed position
Instructions for the correct and safe operation of seacocks shall be included in the owner’s manual.
6.1.1.4
Openings within the boat, such as outboard engine trunks or free-flooding fish bait tanks, shall be considered as possible down-flooding openings.
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6.1.1.5
For boats to be given design category A or B, down-flooding openings not fitted with any form of closing appliance shall only be permitted if they are not in area 1 (refer to ISO 12216) and are essential for cabin or engine ventilation requirements, but these shall at least comply with tightness degree 3.
3.3 PARAGRAPH 6.1.2 DOWNFLOODING POINTS HEIGHT TEST
This test is to demonstrate that a sufficient margin in the freeboard is available with the given hull. The vessel should be treated in the maximum load condition. Figure 3.1 which correspond to Figure 2 of ISO 12217-1, shows that the minimal freeboard height for Category A or B yachts with a LH of 13.33 m can be calculated and is 0.782 m
Figure 3.1 Minimal Freeboard height for category A and category B Yachts
The Hydromax analysis presents the following freeboard heights for the yacht in MML condition:
Table 3.1 Height of the downflooding points in the MML condition.
Downflooding point Freeboard height
Engine Room Ventilation Portside 1.386
Engine Room Ventilation Starboardside 1.386
Salon Entry 0.812
At the most critical points the freeboard is higher than the minimum required height of 0.782 m, with a margin of 3.8 %.
Besides the freeboard height, a downflooding angle requirement is stated in paragraph 6.1.3.
In Table 3.2 the requirement for design Category A can be observed, which corresponds to Table 3 in ISO 12217-1
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Table 3.2 Minimum downflooding angles
Design category
Minimum downflooding angle in degrees
Options 1 and 3, use whichever is the greater
A θ0 +25 30
θ0 can be calculated using the following formulae:
𝜃𝑂 = 11.5 +(24 − 𝐿𝐻)3
520
𝜃𝑂 = 11.5 +(24 − 13.3)3
520= 13.855∘
Now it is possible to calculate the minimum required Downflooding angle per design category A:
θ0min will be 13.855 + 25 = 38.8550
Table 3.3 Downflooding angle check
Downflooding point Cat. A
requirement
Acutal Downflooding
angle
Cat. A pass ratio
Engine Room Ventilation PS
38.850
164 332.2%
Engine Room Ventilation SB 39.5 1.58%
Salon Entry Not immersed -
As such, this meets the requirements as stated in paragraph 6.1.2 of ISO 12217-1 for category B.
To be able to meet the requirement for category A, the Engine Room ventilation inlets need to be moved.
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3.4 PARAGRAPH 6.2 OFFSET-LOAD TEST
The vessel should not flood at various angles of heel. The maximum angle of heel is to occur when all on-board passengers are to stand on the foremost offsets possible from the centreline of the vessel. This check should be performed with the yacht in the MML condition in order to demonstrate that the boat cannot be flooded within those heeled states. For the determination of this angle an experimental determination or a calculation will be sufficient. This last option, the calculation, will be used here. For this test, two conditions are assumed to exist: LC1; All persons on board, on the roof of the salon at 0.75 Loa LC2; All persons on board, on the roof of the wheelhouse at 0.25 Loa The maximal allowable angle of heel the yacht may endure during this offset –load test can be calculated using the following formulae, which is given in ISO 12217-1 paragraph 6.2.3. under a.
𝜃𝑂(𝑅) = 11.5 +(24 − 𝐿𝐻)3
520
𝜃𝑂(𝑅) = 11.5 +(24 − 13.3)3
520= 13.855∘
With all persons is meant; 4 persons with a weight of 85 kg each.
The test is conducted by checking the righting moment of the vessel with the heeling moment induced by the crew. This provides 2 curves, which can be compared in a graph. The intersection of these graphs should comply with the following requirements:
- At point of the intersection of these curves, the heel angle in degrees, θo does not exceed
𝜃𝑂(𝑅) = 11.5 +(24 − 𝐿𝐻)3
520
For this case:
𝜃𝑂(𝑅) = 11.5 +(24 − 13.3)3
520= 13.855∘
- The maximum righting moment occurring up to the downflooding angle is greater than the heeling moment at the offset load test heel angle, θo.
The curve of righting moments for offset load case 1 can be observed in Figure 3.2 and the curve of righting moments corresponding to offset load case 2 can be observed in Figure 3.3.
The results of the test are checked with the here above set requirements, an overview can be observed in Table 3.4
Table 3.4 Offset load result overview
LC1 LC2
Requirement Minimum Actual Value Pass Ratio Actual Value Pass Ratio
At intersection, θo < 13.850 1.7
0 87.63% 1.7
0 87.63%
Rm at downfl. > Hm
LC1 at 38.90 =
6299.8 kg.m 579.6 kg.m 1086.9%
LC2 at 39.80 =
6336.6 kg.m 572.2 kg.m 1107.4%
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Figure 3.2 Curve of righting moments – LC1
Figure 3.3 Curve of righting moments – LC2
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3.5 PARAGRAPH 6.3 RESISTANCE AGAINST WIND AND WAVES
This test will demonstrate if the yacht is able to sufficiently withstand the effects of wind and waves. This test should be performed with the yacht both in the minimum and in the arrival-load condition. The corresponding data are as follows: For the Minimum Operating Condition or MMOC:
Table 3.5 Data associated with the “Minimum Operating Condition”
Displacement, kg LCG, m VCG, m TCG, m
16322.4 5.829 1.884 0.000
For the Arrival Load Condition (MLAC):
Table 3.6 Data associated with the Arrival Load condition
Displacement, kg LCG, m VCG, m TCG, m
16799.1 5.876 1.864 0.003
The zero point is located vertically at the design waterline, longitudinally at the intersection of the aft ship with this waterline and transversally at the centreline of the yacht. During this test the following criteria will be tested:
Calculation of a wind heeling arm, based on windage area and wind velocity, by the use of paragraph 6.3.2
Calculation of the effect of the wind heeling arm on the GZ curve, by comparing 2 area’s underneath the curve; by the use of paragraph 6.3.2. This curve can be observed in Figure 3.4
Calculation of the resistance to wave impact with a required GZ arm and righting moment, by the use of paragraph 6.3.3.
These criteria can be tested by using the stability software HYDROMAX.
Results per tested loadcase can be observed in Table 3.8 to Table 3.14
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Figure 3.4 Righting moment and wind moment criteria.
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For the Minimal Operating Condition:
Table 3.7 Wind heeling arm calculation – Minimal Operating Condition
Code Criteria Value Units Actual Status Pass Ratio
ISO
12
21
7-1
:2013
6.3.2 Wind heeling arm
Wind arm: 𝑎∗ 𝑣2∗𝐴∗(ℎ − 𝐻)
(𝑔∗𝑑𝑖𝑠𝑝.)∗𝑐𝑜𝑠𝑛∗(𝜑) =
constant: 𝑎 ∗ (1
2∗ 𝜌𝑎𝑖𝑟 𝐶𝑑) = 0.3 kg/m
3
wind velocity: v = 28.0 m/s
area centroid height: ℎ =
𝐴
𝐿𝑤𝑙
+ 𝑇𝑚𝑖𝑑𝑊𝐿 2.990 m
Additional area: Aadd = m2
total area: Atot = 7.5 m2
height of lateral resistance:
H = 0
cosine power: n = 0
gust ratio 1
Intermediate values
Model windage area: AMW = 20.946 m2
Area centroid height: AC = 1.850 m
Total windage area: Atot = 28.446 m2
Total area centroid height:
ACtot = 2.151 m
Heel arm amplitude = 0.090 m
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Table 3.8 Rolling in beam waves and wind – Minimal Operating Condition IS
O 1
22
17-1
:2013
Criteria Value Units Actual Status Pass Ratio
6.3.2 Rolling in beam waves and wind
6.3.2 Wind heeling arm
Area1 integrated from the greater of
Angle of equilibrium (with heel arm) =
4.3 deg
to the lesser of
spec. heel angle = 50.0 deg
first downflooding angle= 42.6 deg
angle of vanishing stability (with heel arm)= 65.2 deg
Area2 integrated to the lesser of
roll back angle from equilibrium (with heel arm)=
25.4 deg -21.1
Intermediate values
Equilibrium angle (with heel arm) = 4.3 deg
Area1 (under GZ) = 0.168 m.rad
from 4.30 to 42.6
Area1 (under HA) = 0.0602 m.rad
from 4.30 to 42.6
0
Area1 = 0.1077 m.rad
from 4.30 to 46.2
0
roll back angle from equilibrium (with heel arm)= -21.1
Area2 (under GZ) = -0.0604
from -21.10 to 4.3
0
Area2 (under HA) = 0.0399
from -21.10 to 4.3
0
Area2 = 0.1003
from -21.10 to 4.3
0
Area1 = 0.1077 m.rad
Area2 = 0.1003 m.rad
Area1 / Area2 shall be greater than (>) 100 % 107.42 Pass +7.42
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Table 3.9 Resistance to waves – GZ value – Minimal Operating Condition
ISO
12
21
7-1
:2013
Criteria Value Units Actual Status Pass Ratio
6.3.3 Resistance to waves
Value of GZ
Heel angle at which required GZ constant = 30.0 deg
Required value of GZ at this angle = 0.200 m
Limited by first downflooding angle = 42.6 deg
Intermediate values
Angle at which max. GZ occurs = deg 27.5
GZ at max GZ shall be greater than (>) 0.218 m 0.292 Pass +33.83
Table 3.10 Resistance to waves – RM value – Minimal Operating Condition
ISO
12
21
7-1
:2013
Criteria Value Units Actual Status Pass Ratio
6.3.3 Resistance to waves
Value of RM
Heel angle at which required RM constant = 30 deg
Required value of RM at this angle = 25000 N.m
Limited by first downflooding angle = 42.6 deg
Intermediate values
Angle at which max GZ occurs = deg 27.5
RM at max GZ shall be greater than (>) 27273 N.m 46674.6 Pass +71.14
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For the Arrival Load Condition (MLAC):
Table 3.11 Wind heeling arm calculation – Arrival Load Condition
Code Criteria Value Units Actual Status Pass Ratio
ISO
12
21
7-1
:2013
6.3.2 Wind heeling arm
Wind arm: 𝑎∗ 𝑣2∗𝐴∗(ℎ − 𝐻)
(𝑔∗𝑑𝑖𝑠𝑝.)∗𝑐𝑜𝑠𝑛∗(𝜑) =
constant: 𝑎 ∗ (1
2∗ 𝜌𝑎𝑖𝑟 𝐶𝑑) = 0.3 kg/m
3
wind velocity: v = 28.0 m/s
area centroid height: ℎ =
𝐴
𝐿𝑤𝑙
+ 𝑇𝑚𝑖𝑑𝑊𝐿 2.971 m
Additional area: Aadd = m2
total area: Atot = 7.5 m2
height of lateral resistance:
H = 0
cosine power: n = 0
gust ratio 1
Intermediate values
Model windage area: AMW = 20.759 m2
Area centroid height: AC = 1.859 m
Total windage area: Atot = 28.259 m2
Total area centroid height:
ACtot = 2.154 m
Heel arm amplitude = 0.087 m
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Table 3.12 Rolling in beam waves and wind – Arrival Load Condition IS
O 1
22
17-1
:2013
Criteria Value Units Actual Status Pass Ratio
6.3.2 Rolling in beam waves and wind
6.3.2 Wind heeling arm
Area1 integrated from the greater of
spec. heel angle = 4.1 deg 4.1
to the lesser of
spec. heel angle = 50.0 deg
first downflooding angle= 42.4 deg
angle of vanishing stability (with heel arm)= 67.1 deg
Area2 integrated to the lesser of
roll back angle from equilibrium (with heel arm)=
25..4 deg -21.3
Intermediate values
Equilibrium angle (with heel arm) = 4.1 deg
Area1 (under GZ) = 0.1711 m.rad
from 4.10 to 42.4
0
Area1 (under HA) = 0.0582 m.rad
from 4.10 to 42.4
0
Area1 = 0.1129 m.rad
from 4.10 to 42.4
0
roll back angle from equilibrium (with heel arm)= -21.3
Area2 (under GZ) = -0.0624
from -21.30 to 4.1
0
Area2 (under HA) = 0.0386
from -21.30 to 4.1
0
Area2 = 0.1009
from -21.30 to 4.1
0
Area1 = 0.1129 m.rad
Area2 = 0.1009 m.rad
Area1 / Area2 shall be greater than (>) 100 % 11.82 Pass +11.82
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Table 3.13 Resistance to waves – GZ value - Arrival Load Condition IS
O 1
22
17-1
:2013
Criteria Value Units Actual Status Pass Ratio
6.3.3 Resistance to waves
Value of GZ
Heel angle at which required GZ constant = 30.0 deg
Required value of GZ at this angle = 0.200 m
Limited by first downflooding angle = 42.4 deg
Intermediate values
Angle at which max. GZ occurs = deg 40.5
GZ at max GZ shall be greater than (>) 0.211 m 0.298 Pass +41.1
Table 3.14 Resistance to waves – RM value - Arrival Load Condition
ISO
12
21
7-1
:2013
Criteria Value Units Actual Status Pass Ratio
6.3.3 Resistance to waves
Value of RM
Heel angle at which required RM constant = 30 deg
Required value of RM at this angle = 25000 N.m
Limited by first downflooding angle = 42.45 deg
Intermediate values
Angle at which max GZ occurs = deg 40.5
RM at max GZ shall be greater than (>) 26400 N.m 49159 Pass +86.2
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3.6 PARAGRAPH 6.6 SEAWORTHINESS
In this paragraph the so called Seaworthiness Index (SWIX) is determined Calculate SWIX as follows:
𝑆𝑊𝐼𝑋 = (1.3 ∗ 𝐿𝐻0.5 + 0.7 ∗
13 ) ∗ ( 0.3 ∗
𝑃
+ 90
ℎ𝐵
𝐿𝐻
+ 1.2 ∗ 𝐵𝑊𝐿𝑋 )
Where: LH = Length hull
= MLDC / 1000 P = total propulsion engine power at drive shaft (kW) hB = height of bow structure above static loaded waterline at most forward point on
centreline (m) BWLX = waterline beam, across all hulls in the case of multihulls
P/ = shall not be taken as greater than 42 In which: LH = 13.330 m
= 17.389 ton P = 884 kW [2x Volvo Penta D4-300] hB = 1.666 m BWLX = 3.978 m Using these parameters, the SWIX value calculated for the M.Y. Jetten 45’ Beach is 205. The minimal requirement for Category A yachts is 160.
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4. CONCLUSION
The design of the M.Y. Jetten 45’ Beach meets all the requirements of the ISO 12217-1 for design category A. There is a small margin in the freeboard requirement of 3.8%, this could be overcome by increasing the sill on the salon entry door. It is, however, advisable to keep a close eye on the loading of the vessel during the use of the vessel, since this could have an effect on the stability and freeboard of the yacht.
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15-226-312-011 - Stability ISO 12217 - Update Air Inlet Position Stability report “M.Y. Jetten 45’ Beach” Page | 27
15 December 2015
REFERENCES
ISO 12217-1:2013 (E)
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