1 INTRODUCTION

Each shipping operator will always strive for the ship

to operate optimally and efficiently in the hope that

there will be a better profit margin so that it can

support the continuity of the company to be more

developed [18, 19]. In this paper the author will

present the optimization of space under the main deck

for Landing Craft Utility (LCU) ships. With this

optimization, the cargo will increase and the ship's

revenue will also be more [15, 17]. The LCU ship that

we know so far is a ship whose cargo is always above

the main and the space under the main is unused

Void Space. LCU ships are usually used for crossings

between islands with a crossing that is not too far

away and contains vehicles or heavy equipment. From

the phenomena that exist on passenger ships are

usually made to have a high enough loading capacity,

see figure 1. This makes passenger ships with

optimization of cargo space quite interesting to

discuss [1, 21]. Basically, the tank on the ship can be

used to take advantage of the empty space for the

placement of vehicles as long as a double bottom

construction is made as a replacement [7, 16]. This

double bottom construction serves as a buoyancy

reserve to provide buoyancy when the ship is

operating [5, 11].

Previous research the history of ship design

optimization shows that there are several

contemporary holistic approaches related to the

previous method. The main advantage is that a multi-

objective optimization method of ship design

problems is solved by considering simultaneously

(holistically) all aspects of the ship system design and

not as a collection of parts [3, 8]. Based on previous

studies, the methodology that is often used begins

with the creation of a parametric model that captures

the main details and internal compartments of the

ship, then with the integration of a numerical tool is

developed to determine the performance of each

variant of the ship type [13, 20]. This allows an

Optimization of Space Under Main Deck on Landing

Craft Utility (LCU) Ships to Increase Loading Capacity

S. Sugeng, M. Ridwan, S. Sulaiman & S.F. Khristyson

Diponegoro University, Semarang, Indonesia

ABSTRACT: With this optimization, the cargo will increase and the ship's revenue will also be more. The LCU

ship that we know so far is a ship whose cargo is always above the main and the space under the main is

unused Void Space. The purpose of this study is to determine the optimization value of the use of space under

the main deck of the Landing Craft Utility (LCU) ships. method used in this study is a comparison with several

previous ship approaches to produce evaluation results from the addition of loading space under the main deck

and calculation of stability using computational software approximation. LCU design of under main deck space

with a maximum vehicle value can accept a vertical moment of 2750 mm. With a structural strength of 13150

tons. A series of numerical experiments show that the proposed method can effectively produce a satisfactory

LCU ship design optimization plan for ship owners.

http://www.transnav.eu

the International Journal

on Marine Navigation

and Safety of Sea Transportation

Volume 16

Number 1

March 2022

DOI: 10.12716/1001.16.01.10

100

analysis that can evaluate many functions and design

constraints, as well as part of the optimization

problem [2, 10]. The differences that have been

identified by the previous authors are the lack of a

way to capture the uncertainty inherent in the

physical environment and a suitable numerical model,

an emerging design opportunity that is expected to

provide a more pragmatic representation of the

solution space to decision makers [4, 8]. Meanwhile

several studies show that there is a modern approach

to ship design, which is implemented in practice

using appropriate software platforms and tools,

introducing parametric design into the ship design

process, allowing exploration of considerable design

space before a decision is made [12, 14]. This approach

is often used in the modular ship design process,

where the major parts of the ship (hull, engines,

fixtures, navigation bridges, etc.) are considered as

modules with specific functionality, connectivity, and

associated space and weight requirements [6, 9].

The limitation of this research is that the shape

used is the development of the LCU ship, and the size

of the vehicle used is 16 Light Truck 2.5 Tons on the

cargo section of the ship, the calculation includes the

stability of the ship with the ability to carry load

capacity. The purpose of this study is to determine the

optimization value of the use of space under the main

deck of the Landing Craft Utility (LCU) ships.

Figure 1. LCU ship after space optimization

Then after calculating the value of the stability of

the ship, the data obtained, see table 1.

2 DESCRIPTION

The method used in this study is a comparison with

several previous ship approaches to produce

evaluation results from the addition of loading space

under the main deck. So it is hoped that these

additions can provide the best optimization value

from this design process, see figure 2.

Table 1.Calculation Stability Criteria LCU ship after space optimization

__________________________________________________________________________________________________

Item Name Quant. Weight Long. Vert. Trans. FSM FSM

tonne Arm m Arm m Arm m tonne.m Type

__________________________________________________________________________________________________

Lightship 1 625.3 19.848 4.417 0.000 0.000

Crews & Effect 1 2.200 7.570 9.710 0.500 0.000

Provision Store 1 0.500 2.000 9.000 2.500 0.000

Cargo Hold 1 40.00 28.380 2.200 0.000 0.000

Cargo on Deck 1 188.7 25.310 5.300 0.000 0.000

Cargo on M-Deck (under SS) 1 7.500 7.000 4.850 0.000 0.000

Ballast (aft)p s(fr. 1 s/d 3) 0% 0.0000 2.044 2.730 -2.754 0.000 Maximum

Ballast(aft)sb (fr. 1s/d 3) 50% 11.36 2.088 2.091 2.709 14.538 Maximum

FW. Sanitary (fr.1 s/d 3) 97.9% 6.298 2.077 2.913 -5.711 0.806 Maximum

Sludge (fr. 1 s/d 3) 97.9% 6.298 2.077 2.913 5.711 0.806 Maximum

FO. Settling(ps)(fr.13 s/d 14) 0% 0.000 14.250 2.085 -3.468 0.000 Maximum

FO. Settling(sb)(fr. 13 s/d 14 20% 5.870 14.250 0.551 2.876 28.750 Maximum

FWT (ps2) (fr.15 s/d 19) 97.9% 17.01 19.508 0.628 -4.261 34.324 Maximum

FWT (sb1) (fr.15 s/d 19) 97.9% 13.15 19.503 0.523 1.168 6.912 Maximum

Ballast (ps) (fr.19 s/d 24) 100% 39.69 26.250 0.588 -2.916 0.000 Maximum

Ballast(sb) (fr.19 s/d 24) 100% 39.69 26.250 0.588 2.916 0.000 Maximum

FOT (ps1) (fr.24 s/d 29) 0% 0.000 33.732 0.535 -1.164 0.000 Maximum

FOT (sb1) (fr.24 s/d 29) 0% 0.000 33.732 0.535 1.164 0.000 Maximum

Ballast (ps)(fr.29 s/d 32) 100% 12.24 39.450 0.640 -1.729 0.000 Maximum

Ballast (sb)(fr.29 s/d 32) 100% 12.24 39.450 0.640 1.729 0.000 Maximum

FPT (fr. 33 s/d .... ) 0% 0.000 45.167 3.097 0.000 0.000 Maximum

FO. Service day Tank (Ps) 97.9% 3.020 4.600 2.932 -1.500 0.490 Maximum

FO. Service day Tank (Sb) 97.9% 3.335 11.350 2.736 3.000 1.258 Maximum

FWT (ps1) (fr.15 s/d 19) 0% 0.000 19.503 0.533 -1.169 0.000 Maximum

FWT (sb2) (fr.15 s/d 19) 0% 0.000 19.507 0.636 4.265 0.000 Maximum

FOT (ps2) (fr.24 s/d 29) 0% 0.000 33.421 0.662 -4.143 0.000 Maximum

FOT (sb2) (fr.24 s/d 29) 0% 0.000 33.421 0.662 4.143 0.000 Maximum

Fixed Ballast 1 38.40 24.650 1.500 -0.047 0.000 UserSpec

Total = LCG = VCG = TCG = FSM = FS corr.= VCG fluid=

1073 21.590 3.851 -0.003 87.885 0.082 3.933

__________________________________________________________________________________________________

101

Figure 2. Research Methodology

Calculation of stability using computational

software, where the value obtained from the

calculated data will later be poured in the form of a

graph to make it easier to analyze the results of the

study. Results of the evaluation of the addition of

space under the main deck become a separate

consideration for ship designers to provide a good

loading and unloading system as well. system in

question is an elevator, see Figure 3.

Figure 3. Elevator Cassis

The elevation system mounted on the ship is a lift

system design that makes it easy for vehicles to access

up and down. This system does not require a lot of

space for operational processes, however it requires

hydraulic power and limits on the weight of trucks

that can be accessed for the up and down process. The

standard used in this stability calculation is in

accordance with the IMO standard, see figure 4.

Figure 4. Load Case Criteria

3 RESULTS OF THE MEASUREMENTS

From the design attributes, the design of this

additional loading space is categorized into several

models which are illustrated by Figure 5.

Figure 5. Design by Importance

Some of these aspects indicate the need to review

several considerations in determining the design.

Figure 6. Importance by Design

From this comparison, it can be seen that designs 1

and 2 have the closest parameters, where in terms of

the comfort level, the value is very high, while the cost

of each has a value that is relatively almost the same.

From designs 1 and 2, stability analysis was then

carried out and then obtained the results of the

stability criteria as set out in Figure 7.

Figure 7. Stability Criteria

Results show the value of GZ at an angle of 70

degrees in design 2 is better than the previous

researchers and design 1. From a fairly critical angle,

the length of the moment arm returns to its original

position up to 7.6 m. In balance with the distance from

Keel to Metacenter and Keel to Buoyancy which

shows a good trend as well. Results of the comparison

of VCG with IMO show conditions that meet the

standard requirements, see table 2. So that this second

design can be used as a reference in optimizing the

space under the main deck to increase the capacity of

the ship's truck loading space.

102

Table 2. Result VCG comparison with IMO standard

__________________________________________________________________________________________________

Code Criteria Value Units Actual Remark

__________________________________________________________________________________________________

A.749(18) Ch3 – 3.1.2.1: Area 0 to 30 0.055 m.rad 0.165 Pass

Design criteria 3.1.2.1: Area 0 to 40 0.090 m.rad 0.899 Pass

applicable to all 3.1.2.1: Area 30 to 40 0.030 m.rad 0.287 Pass

ships 3.1.2.2: Max GZ at 30 or greater 0.200 m 1.757 Pass

3.1.2.3: Angle of maximum GZ 25.0 deg 25.0 Pass

3.1.2.4: Initial GMt 0.150 m 5.185 Pass

A.749(18) Ch3 – 3.2.2: Severe wind and rolling Pass

Design criteria Wind arm: a P A (h - H) / (g disp.) cos^n(phi)

applicable to all constant: a = 0.99

ships wind pressure: P = 504.00 Pa

area centroid height (from zero point): h = 6.344 m

total area: A = 278.640 m^2

H = mean draught / 2 1.133 m

cosine power: n = 0

gust ratio 1.5

Area2 integrated to the lesser of

roll back angle from equilibrium (with steady heel arm) 1.0 (-0.3) deg -0.3

Area 1 upper integration range, to the lesser of:

angle of max. GZ 25.0 deg 25.0

angle of max. GZ above gust heel arm 25.0 deg

Angle for GZ(max) in GZ ratio, the lesser of:

spec. heel angle 45.0 deg 45.0

Select required angle for angle of steady heel ratio:

Deck Edge Immersion Angle Pass

Angle of steady heel shall not be greater than (<=) 16.0 deg 0.7 Pass

Area1 / Area2 shall not be less than (>=) 100.000 % 27427.2 Pass

Area 1 shall not be less than (>=) 0.000 m.rad 0.414 Pass

Intermediate values

Heel arm amplitude m 0.069

Equilibrium angle with steady heel arm deg 0.7

Equilibrium angle with gust heel arm deg 1.1

Area1 (under GZ), from 1.1 to 25.0 deg. m.rad 0.457

Area1 (under HA), from 1.1 to 25.0 deg. m.rad 0.043

Area1, from 1.1 to 25.0 deg. m.rad 0.414

Area2 (under GZ), from -0.3 to 1.1 deg. m.rad 0.001

Area2 (under HA), from -0.3 to 1.1 deg. m.rad 0.002

Area2, from -0.3 to 1.1 deg. m.rad 0.002

Area B / Area A = 1.055/0.669 1.000 1.580 Pass

__________________________________________________________________________________________________

4 DISCUSSION OF RESULTS

From the comparison results of several models and

previous studies, it is known that the LCU design

value still enters the IMO criteria. This can be seen

from the VCG value and the mass structure which is

quite ideal for the number of vehicles accommodated,

see figure 8

Figure 8. VCG Comparison and Structure mass

LCU design of under main deck space with a

maximum vehicle value can accept a vertical moment

of 2750 mm. With a structural strength of 13150 tons,

it still shows a fairly good capacity from the design

attribute, which has a significant value. This is in line

with previous research which showed the influence of

the increasing number of vehicle capacities that can be

loaded, the more vertical gravity is formed.

5 FINAL CONCLUSIONS

The second design is designed to get a car layout with

the maximum level of comfort and total convenience.

In order to reduce the problems related to the carrying

capacity of the vehicle, a ship rolling-stability

heuristic approach based on VCG feedback (positive

and negative) was taken into account. Based on the

guidance mechanism, the results of the structure mass

calculation describe the guidance provided by the

existing vehicle layout to the room below the main

deck, while based on the elevator system mechanism,

it is a solution to access vehicle arrivals to the vehicle

layout. A series of numerical experiments show that

the proposed method can effectively produce a

satisfactory LCU ship design optimization plan for

ship owners.

REFERENCES

1. Andersson, J. et al.: Review and comparison of methods

to model ship hull roughness. Applied Ocean Research.

103

99, 102119 (2020).

https://doi.org/10.1016/j.apor.2020.102119.

2. Andric, J. et al.: Influence of different topological

variants on optimized structural scantlings of passenger

ship. Marine Structures. 78, 102981 (2021).

https://doi.org/10.1016/j.marstruc.2021.102981.

3. Andric, J. et al.: Multi-level Pareto supported design

methodology- application to RO-PAX structural design.

Marine Structures. 67, 102638 (2019).

https://doi.org/10.1016/j.marstruc.2019.102638.

4. Bulian, G. et al.: Complementing SOLAS damage ship

stability framework with a probabilistic description for

the extent of collision damage below the waterline.

Ocean Engineering. 186, 106073 (2019).

https://doi.org/10.1016/j.oceaneng.2019.05.055.

5. Cepowski, T.: The prediction of ship added resistance at

the preliminary design stage by the use of an artificial

neural network. Ocean Engineering. 195, 106657 (2020).

https://doi.org/10.1016/j.oceaneng.2019.106657.

6. Dogrul, A. et al.: Scale effect on ship resistance

components and form factor. Ocean Engineering. 209,

107428 (2020).

https://doi.org/10.1016/j.oceaneng.2020.107428.

7. Francescutto, A.: Intact stability criteria of ships – Past,

present and future. Ocean Engineering. 120, 312–317

(2016). https://doi.org/10.1016/j.oceaneng.2016.02.030.

8. Fu, T. et al.: Simulating the dynamic behavior and

energy consumption characteristics of frozen sandy soil

under impact loading. Cold Regions Science and

Technology. 166, 102821 (2019).

https://doi.org/10.1016/j.coldregions.2019.102821.

9. Jafaryeganeh, H. et al.: Application of multi-criteria

decision making methods for selection of ship internal

layout design from a Pareto optimal set. Ocean

Engineering. 202, 107151 (2020).

https://doi.org/10.1016/j.oceaneng.2020.107151.

10. Kaidi, S. et al.: Numerical modelling of the muddy layer

effect on Ship’s resistance and squat. Ocean Engineering.

199, 106939 (2020).

https://doi.org/10.1016/j.oceaneng.2020.106939.

11. Peng, H. et al.: Wave pattern and resistance prediction

for ships of full form. Ocean Engineering. 87, 162–173

(2014). https://doi.org/10.1016/j.oceaneng.2014.06.004.

12. Priftis, A. et al.: Multi-objective robust early stage ship

design optimisation under uncertainty utilising

surrogate models. Ocean Engineering. 197, 106850

(2020). https://doi.org/10.1016/j.oceaneng.2019.106850.

13. Skoupas, S. et al.: Parametric design and optimisation of

high-speed Ro-Ro Passenger ships. Ocean Engineering.

189, 106346 (2019).

https://doi.org/10.1016/j.oceaneng.2019.106346.

14. Song, S. et al.: Validation of the CFD approach for

modelling roughness effect on ship resistance. Ocean

Engineering. 200, 107029 (2020).

https://doi.org/10.1016/j.oceaneng.2020.107029.

15. Tan, X. et al.: Preliminary design of a tanker ship in the

context of collision-induced environmental-risk-based

ship design. Ocean Engineering. 181, 185–197 (2019).

https://doi.org/10.1016/j.oceaneng.2019.04.003.

16. Terziev, M. et al.: A posteriori error and uncertainty

estimation in computational ship hydrodynamics. Ocean

Engineering. 208, 107434 (2020).

https://doi.org/10.1016/j.oceaneng.2020.107434.

17. Tillig, F., Ringsberg, J.W.: Design, operation and

analysis of wind-assisted cargo ships. Ocean

Engineering. 211, 107603 (2020).

https://doi.org/10.1016/j.oceaneng.2020.107603.

18. Weintrit, A., Neumann, T.: Advances in marine

navigation and safety of sea transportation.

Introduction. Advances in Marine Navigation and

Safety of Sea Transportation - 13th International

Conference on Marine Navigation and Safety of Sea

Transportation, TransNav 2019. 1 (2019).

19. Weintrit, A., Neumann, T.: Safety of marine transport

introduction. In: Safety of Marine Transport: Marine

Navigation and Safety of Sea Transportation. pp. 1–4

(2015).

20. Yuan, Y. et al.: A design and experimental investigation

of a large-scale solar energy/diesel generator powered

hybrid ship. Energy. 165, 965–978 (2018).

https://doi.org/10.1016/j.energy.2018.09.085.

21. Zhang, W. et al.: An integrated ship segmentation

method based on discriminator and extractor. Image and

Vision Computing. 93, 103824 (2020).

https://doi.org/10.1016/j.imavis.2019.11.002.