Lane Meters Correlation Analysis towards the Main Dimensions of

Ro-ro Ships under 2000 GT

Bagus Gelis Pratama Putra

1,a

, Wasis Dwi Aryawan and Aries Sulisetyono

Department of Naval Architecture, Institut Teknologi Sepuluh Nopember, Indonesia

Keywords: Ferry Ro-Ro, Gross Tonnage, Lane Meter, Pearson Correlation, Regression.

Abstract: The size of ro-ro ships in Indonesia was clustered based on Gross Tonnage (GT). Other units, Lane Meter

(LM) can better describe the possible condition of vehicle loads on ships. LM naturally represents the

combined length of the entire lane in meters that can be used to load vehicles. This study aims to discover the

correlation between the value of LM and GT on ro-ro ships' main dimensions. It proposes mathematical

models that can properly estimate the LOA, LPP, and B of the ro-ro ship using LM as an input value. To

measure the value of LM, this study used 94 ro-ro ships with sizes below 2000 GT and 90 m length.

Correlation test was done through Pearson correlation method by performing several linear regression and

ANOVA tests. LM provides a better correlation than GT on LOA, LPP, and B with a correlation value (r) ≥

0.75. Visible results of the linear regression of LM properly showed strong determinant value, with value of

R Square ≥ 0.75. Meanwhile standard ANOVA tests of LM performed on LOA, LPP, and B positively have

significance values (sig. ≤ 0.05).

1 INTRODUCTION

Size of Ro-ro ships in Indonesia was clustered with

Gross Tonnage or GT. Gross tonnage is the

calculation of the volume of all space located below

the deck of the ship. It includes the volume of the

enclosed space located above the deck with the

contents of the room along with all the enclosed

spaces located above the top deck (superstructure). In

fact, there is other unit better describe the condition

of vehicle loads on ro-ro vessels rarely used in

Indonesia, namely, Lane Meter. Lane Meter (LM) is

a unit deck area for ro-ro ships in which one lane is

represented by a width of 2 meters and a length of 1

meter (ibiblio, 2008). Moreover, lane meter describes

the deck areas on a particular ship used for vehicle

placement. Therefore, it is important to estimate the

loading capacity of the ship, particularly in initial

stage.

In ship design process, the initial stage is very

critical because the design of a particular ship has to

meet certain requirements. Ordinarily, the ship design

process is carried out to follow in a spiral design

process consisting of several stages, namely, Concept

Design, Preliminary Design, Contract Design, and

Detail Design (Watson, 1998). At Concept Design

stage, the main ship size components like length

between two perpendiculars (LPP), breadth (B),

draught (T), and height (H) are determined. In the

process of determining the ship particular, ship owner

requirements are used to identify load specifications.

Besides GT, a measurement in LM can be used to

start the design process. In this study, Lane Meter

measurements will be based on ships operating in

Indonesian waters and will be correlated with the

particular of the ship. This will shorten the spiral

design process.

2 RESEARCH DESCRIPTION

This study aims to determine the correlation between

the value of GT and LM on ro-ro ships to ship main

dimensions in order to obtain mathematical models

that correlates with the value of LM. The theoretical

benefit of this research is to give an alternative

mathematical model for determining the size of ro-ro

ships under 2000 GT and 90 m. The practical benefit

of this research for naval architects is to shorten the

design process in determining the main size the ships

under study.

Putra, B., Aryawan, W. and Sulisetyono, A.

Lane Meters Correlation Analysis towards the Main Dimensions of Ro-ro Ships under 2000 GT.

DOI: 10.5220/0010864100003261

In Proceedings of the 4th International Conference on Marine Technology (senta 2019) - Transforming Maritime Technology for Fair and Sustainable Development in the Era of Industrial

Revolution 4.0, pages 141-147

ISBN: 978-989-758-557-9; ISSN: 2795-4579

141

This research was carried out under the following

procedures:

2.1 Literature Review

2.1.1 Cargo Mass Unit

At the beginning of the design process, a ship is

always delivered about the original purpose of

shipbuilding. As a means of transportation, ships are

intended to transport several goods frequently

referred to as cargo. In most cases, cargo can be

defined as goods transported by a means of

transportation for commercial purposes. There are

many forms of cargo, ranging from bulk, dry bulk,

containers, or even something in units. In addition,

the cargo itself is divided into several units that have

been agreed globally. The cargo mass units

commonly used on ships can be stated as follows

(Marine Environment Protection Committee, 2009):

• For dry cargo carriers, liquid tankers, gas tankers,

ro-ro cargo ships and general cargo ships, the

units of cargo transported are using metric tons (t);

• For container ships that only handle containers,

they must use the number of containers (TEU) or

metric tons (t) of the combined mass of the cargo

and containers;

• For ships carrying a combination of containers

and other loads, a 10 t TEU mass can be used to

load TEUs with payloads and 2 t for TEUs with

empty loads; and

• For passenger ships, including ro-ro passenger

ships, must employ the number of passengers or

gross tonnage of the ship (GT);

In some cases, the mass unit of cargo used can be

stated as follows:

• For car ferries and car carriers, must employ the

number of car units or lane meters occupied;

• For containers, total TEU (empty or full.); and

• For railroad carriers and ro-ro vessels, the number

of carriages and vehicles carried, or lane meters

occupied.

2.1.2 Gross Tonnage

Gross tonnage is the calculation of the volume of all

space located below the deck of the ship plus the

volume of the enclosed space located above the deck

with the contents of the room along with all the

enclosed spaces located above the top deck

(superstructure). Gross tonnage is expressed in tons,

which represent a unit volume of 100 cubic feet,

which is equivalent to 2.83 cubic meters (IMO, 1969).

In its application to the Ro-Ro Ferry, the GT is

used to express the unit size of the Ro-Ro ship.

Following KM 53 of 2002 (Menteri Perhubungan

R.I., 2002), the Ferry port classification is divided

into 3 (three) classes based on the vessel GT capacity.

At Class-I Ferry Port, the dock used to accommodate

ships with a size above 1000 GT. Class-II Ferry Port,

the pier used to accommodate ships with capacities

ranging from 500 GT to 1000 GT. Whereas at Class-

III Ferry Port, the dock used to accommodate ships

with a capacity of under 500 GT.

As part of the size of the Ro-Ro ferry, the value of

the gross tonnage of the ship does not represent the

exact dimensions of the ship. Based on data obtained

in 2012 in previous studies (Asri, 2016), several ships

with larger main sizes have smaller gross tonnage

than other smaller vessels. And also explained that

there are some ships with the same main dimensions

but have different tonnage. It is because the value of

gross tonnage itself is a function of closed space.

Whereas every ship with the same main dimensions

could have various enclosed spaces so that might

produce different gross tonnage calculations. On the

other hand, gross tonnage more represents the

capacity of the loaded passenger space.

2.1.3 Lane Meter

In addition to using the gross tonnage units (GT) the

vehicle carrier equally has other capacity units. Ro-

Ro cargo ships are usually measured using lane

meters (Wathne, 2012). Lane meter represents a

method of measuring Ro-Ro ship space capacity

where each unit of space (linear meter) represented by

a deck area with a length of 1.0-meter and width of

2.0 meters (IFA, 2006).

Typically, ro-ro ships occupied a loading space to

transport vehicle which typically arranged lengthwise

on the deck. The placement of vehicles on this ship was

divided into several loading lanes. As explained

before, the Lane Meter (LM) unit is described as a deck

area of one lane with a width of two meters and one

meter long, or the equivalent of 2 square meters

(21,528 square feet). Practically, the LM unit

represents the combined length of the entire lane in

meters that can use to load vehicles on ro-ro ships. In

its application, the size of a conventional car in Europe

will require an area of six LM, and for European semi-

trailer trucks require an area of 18 LM.

The strength of the lane meter is it typically

reflects the number of vehicles that can be properly

loaded on the car deck. By using a lane meter,

whatever the length of the vehicle can be equalized

by managing this unit. Which represents the overall

length of the lane on the ship that can accommodate

vehicles on the deck. When synchronized, it can

properly explains that by using functional capacity of

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100 LM, the ship can transport a possible total of 20

operational units of Gol IV vehicles with a length of

5 meters . It can transport 10 Gol V Trucks with a

length of 7 meters and 6 privates Gol IV vehicles.

Compared to the Gross Tonnage unit with a value of

300 GT, the number of vehicles that can be loaded by

the ship could not be precisely ascertained. So far, the

practitioners only have predicted based on their

intuition by comparing with the size of the ship they

knew.

Disadvantages of lane meter unit is that the

remaining unit of weight is unable to represent the

payload directly. The definition of this unit,

nevertheless, followed by some debates in practice.

Although by definition it is known that the width of

the lane referred to in the lane meter is two meters,

but in practice, some vehicle types occupy a width of

more than two meters.

In terms of loading on ships in Indonesia, the

loading of vehicles on ships has been regulated in the

Technical Guidelines for Minimum Service

Requirements for River, Lake, and Crossing Vessels

(Direktorat Jenderal Perhubungan Darat, 1994). The

regulation stipulates that the distance between

vehicles when loading on board is 0.6 m (600 mm).

While the distance of the vehicle to the ship's wall is

0.6 m (600 mm). Concerning the description of the

LM unit, which occupies a width of two meters and

the ministerial regulation. It can be equalized that one

lane of vehicles on a ship provides a width of 2.6 m

with an additional 0.3 m per side. So that the

arrangement of vehicle lanes by implementing these

requirements represents the preparation of LM values

on the deck of the vehicle and accommodate

variations in the width of the vehicle that is on the

ship.

2.1.4 Present Ship Sizing by Lane Meter

Determination of the main dimensions of a ro-ro ferry

boat using input lane meter values has been done

before (Kristensen, 2006). This study utilized data

from ro-ro vessels of 500 to 3500 LM. Using

statistical analysis, a mathematical model was

obtained. It shows the correlation between LPP and

LM that is defined by the equation:

Lpp = 110 + (LM −1000) / 25

(1)

Where:

Lpp : Length between perpendicular

LM : Lane meter

The subsequent research was conducted again

(Kristensen, Analysis of technical data of Ro-Ro

ships, 2016), with discussions focused on Ro-Ro

ships. The data in the study were widely analysed

based on various parameters that have been collected

and examined to develop a formula for the systematic

calculation of technical data on Ro-Ro cargo ships.

So we obtain 2 (two) conditions stated in the

following equation:

𝐿𝑝𝑝  20.4𝐿𝑀

.

for LM < 1.402

(2)

and

𝐿𝑝𝑝  11.18𝐿𝑀

.

, LM ≥ 1.402

(3)

The other variables can be obtained using the

followings:

𝐵  5.49𝐿𝑀

.

(4)

𝑇  1.9𝐿𝑀

.

, LM < 2.000

(5)

𝑇  5.81  0.0003𝐿𝑀, LM ≥ 2.000

(6)

𝐷  0.00172𝐿𝑀  11.42 (7)

Based on data displayed by (Kristensen, 2016),

the length of the ship shown has an average LPP size

above 100 m. The determination of the equation for

ships with LPP size below 100 m needs to be

reviewed mathematically.

Based on data showed in Table 1, the

mathematical model presented, has a relatively

significant deviation compared to the initial value.

With an average difference of 97% and 68% of the

genuine value. Typically, there is an improvement

that occurs between the equations defined by

Kristensen from equation (1) to equation (2), where

the difference gets closer. For this reason, it is

necessary to make adjustments to ships in Indonesian

waters.

Table 1: Comparison of Krinstensen's LPP calculations with the reality.

Ro-Ro GT LM LPP (Real) LPP (2-1) Dev (2-1) LPP (2-2) Dev (2-2)

288 50 33,50 72,00 215% 56,19 168%

560 90 40,15 73,60 183% 65,43 163%

634 126 41,35 75,04 181% 71,39 173%

1120 137 50,50 75,48 149% 72,95 144%

284 44 28,32 71,76 253% 54,36 192%

197% 168%

Lane Meters Correlation Analysis towards the Main Dimensions of Ro-ro Ships under 2000 GT

143

2.2 Lane Meter Variable Measurement

At the beginning of this study, the value of LM was

unknown. Therefore, it is necessary to measure it

first. To measure the value of LM, this study used 94

ro- ro ships with sizes below 2000 GT and 90 m

length. Lane Meter (LM) measurements are obtained

by re- sketching the car deck arrangement based on

the general arrangement drawings or similar that have

been collected previously. LM measurements are

adjusted according to the description in 2.1.3. In the

shown one of the LM measurement values that will

be used as variables in this study.

Figure 1: KMP Kormomolin 884 GT 77 LM.

2.3 Correlation Test

Correlation coefficient is a statistical measurement of

covariance or association between two variables. The

value of the correlation coefficient has a range

between +1 and -1. The correlation coefficient shows

the strength of the linear relationship and the direction

of the relationship of two random variables. If the

correlation coefficient is positive, then the two

variables has a direct relationship.

2.4 Linear Regression Analysis

Regression analysis explores the relationship

between one or more variables/independent variables

(X) with one dependent variable (Y). A form of

relationship related to response (Y) and regressor (X)

represents a linear relationship, which can be written

as follows (Walpole, 2012):

𝑌ab𝑥

(8)

Here, (a) is called intercept and (b) is the direction

coefficient or beta coefficient.

3 DATA ANALYSIS

3.1 LM and GT Correlation Test

In this study, the correlation value (r) was obtained

using Pearson's Correlation theory. Correlation

calculations performed on LM as an independent

variable on many dependent variables included in the

main dimensions of the ship. The dependent variable

considered to be determined in this study. The value

is GT, LOA, LPP, B, T, H, L/B, L/T, B/T, and

Payload. Several correlation tests were also carried

out on the dependent variables. There are LM, LOA,

LPP, B, T, H, L/B, L/T, B/T, and Payload, using GT

as an independent variable. From this process, we will

determine which variables are correlated with LM

values. Correlation value has a range starting from the

value of "zero" which means there is no correlation at

all. The correlation value of "one" means it has a

perfect correlation value. Performed by statistical

correlation calculations, the correlation results

obtained were shown in Table 2.

Table 2 explains that the Lane Meter variable

provides a direct correlation to the variables GT,

LOA, LPP and B on ro-ro ships, compared between

the dependent variables between LM and GT. It could

be concluded that LM provides a more exact

correlation than GT on LOA, LPP, B, L/B and

Payload values. The T and H values better correlated

to the GT variable than LM.

3.3 Regression Modeling

3.3.1 Regression Model of GT

Linear regression analysis is used to find out how

much effect the gross tonnage value (GT) has on Lane

Mater (LM) and obtain its mathematical model.

Based on the model, it is recognized that the value of

the coefficient of determination R square = 0.825. It

shows that the effect of the Lane Meter (LM) on gross

tonnage (GT) is 82.5%. Based on the ANOVA test,

results obtained showed significance value of 0.000

(< 0.05), thus resulting regression model can be used

to predict the variable GT. The coefficient calculation

Table 2: Correlation Test Results.

Correlation LM GT

0,884

GT 0,884

LOA 0,912 0,845

LPP 0,914 0,847

B 0,874 0,817

T 0,726 0,737

H 0,713 0,723

L/B 0,525 0,487

L/T 0,416 0,297

T/H 0,392 0,393

B/T -0,051 -0,139

load (ton) 0,651 0,624

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results explained a constant value of -31,382 while

the Lane Meter value (regression coefficient) of 6,034

so that the regression equation can be written with:

𝐺𝑇  31,382  6,034 𝐿𝑀

(9)

Based on the results of tests conducted, it can be

concluded that Lane Mater (LM) affects GT value.

The resulting regression equation can described by

following Figure 2.

Figure 2: Regression of LM – GT.

3.3.2 Regression Model of LOA

Linear regression analysis is used to find out how the

value of the overall length of the ship (LOA) has a

significance effect towards the lane meter (LM) in

order to obtain the mathematical model. Based on the

model performed, it was recognized that the value of

the coefficient of determination R square = 0.832,

which shows that the effect of the Lane Meter (LM)

on the overall length of the ship (LOA) of 83.2%.

Based on the ANOVA test, results obtained a

significance value of 0,000 (< 0.05), then the resulting

regression model can be used to predict LOA

variables. The coefficient calculation results

indicated a constant value of 22,632 while the lane

meter value (regression coefficient) of 0.223 so that

the regression equation can written by:

𝐿𝑂𝐴  22,632  0.223 𝐿𝑀

(10)

Based on the results of tests conducted, it can be

concluded that Lane Meter (LM) affects the LOA.

The following regression equation can be described

by Figure 3.

Figure 3: Regression of LM – LOA.

3.3.3 Regression Model of LPP

Linear regression analysis was used to find out how

much effect the length of the ship's vertical line (LPP)

on the lane meter (LM) and obtain the mathematical

model. Based on the model performed, it could be

recognized that the value of the coefficient of

determination R Square = 0.835. It shows the effect

of LM on LPP is 83.5%. Based on the ANOVA test,

results obtained a significance value of 0.000 (<

0.05), therefore the resulting regression model can be

used to predict LPP variables. The result of the

coefficient calculation shows the constant value is at

20,039 while the Lane Meter value (regression

coefficient) is at 0.197 so that the regression equation

can be written with:

𝐿𝑃𝑃  20,039  0.197 𝐿𝑀

(11)

Based on the results of tests conducted, it

concluded that Lane Mater (LM) affects LPP. The

resulting regression equation can be described with

the following by Figure 4.

Figure 4: Regression of LM – LPP.

3.3.4 Regression Model of B

Linear regression analysis was also used to find out

how much effect the value of the width of the ship (B)

Lane Meters Correlation Analysis towards the Main Dimensions of Ro-ro Ships under 2000 GT

145

on the lane meter (LM) and obtain a mathematical

model. Based on the model, it could be recognized

that the value of the coefficient of determination R

Square = 0.764. It shows that the effect of the

independent variable in the form of lane meter (LM)

to the dependent variable (B) attends 76.4%. Based

on the ANOVA test results obtained a significance

value of 0,000 (< 0.05), therefore resulting regression

model can be used to predict B variables. The

coefficient calculation result shows the constant's

value of 7,698 while the lane meter value (regression

coefficient) of 0.038 so that the regression equation

can written by:

𝐵  7,698  0.038 𝐿𝑀

(12)

Based on the results of the tests conducted, it can

be inferred that Lane Mater (LM) affects B. The

resulting regression equation can be described by the

following Figure 5.

Figure 5: Regression of LM-B.

3.4 Model Comparison

In order to find out the accuracy of mathematical

models, a comparison must be performed between the

real LPP variable values and the LPP calculations.

LPP calculations was obtained by using the equation

(11). Using the compared result in Table 2, it was

inferred that the LPP value produced provided quite a

considerable accuracy with a difference of 3% for the

sample ship. When compared with the equations (1)

and (2) in Table 1 the value is already more

representative of the initial value.

The variable B was also compared between the

value of the real variable B and the B calculation. The

B calculations are obtained by using the equation (4)

and the equation (12). From the results in Table 3. It

could be seen that the value of B produced provided

quite a precise accuracy with a difference of 1% for

the sample ship. When compared to the equation (4)

with a difference of 15%, the value produced by (12)

is much closer to the initial value.

4 CONCLUSION

1. Based on the results of the correlation test, Lane

Meter provides a very strong correlation to the

variables GT, LOA, LPP and B on ro-ro ships.

Where the value of each of these variables is GT:

0.884, LOA: 0.912, LPP: 0.914, B: 0.874.

2. Based on the results of the correlation test, LM

values provide a more exact correlation than GT

on LOA, LPP, B, L/B and Payload variables on

the main size of ro-ro vessels.

3. For a very strong correlation, a mathematical

model is adopted to estimate the ferry ro-ro with a

size below 2000 GT and a length below 90 m:

 LM against GT

𝐺𝑇  31,382  6,034 𝐿𝑀, R

0.825

 LM against LOA

𝐿𝑂𝐴  22,632  0.223 𝐿𝑀, R

0.832

 LM to LPP

𝐿𝑃𝑃  20,039  0.197 𝐿𝑀, R

0.835

 LM against LPP

𝐵  7,698  0.038 𝐿𝑀, R

0.764

Table 2: Comparison model (11) to real LPP.

Ro-Ro GT LM LPP (Real) LPP (11) Dev (11)

288 50 33,50 29,89 89%

B 560 91 40,15 37,97 95%

C 634 126 41,35 44,86 108%

1.120 137 50,50 47,03 93%

E 284 44 28,32 28,71 101%

97%

Table 3: Comparison model (4) and (12) to real B.

Ro-ro GT LM

(Real) B (4) Dev(4) B (12) Dev (12)

288 50 9,50 11,64 122% 9,60 101%

560 91 12,00 13,05 109% 11,16 93%

634 126 12,00 13,89 116% 12,49 104%

1120 137 14,00 14,12 101% 12,90 92%

284 44 9,00 11,35 126% 9,37 104%

115% 99%

senta 2019 - The International Conference on Marine Technology (SENTA)

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4. Based on model comparison, this model

representation was closer to the initial value of ro-

ro ships than the present model.

5. In determining T and H values, another approach

which is more correlated than the Lane Meter was

needed.

As stated above, this research is in accordance

with the results of this study. The result equations in

this study represents more about the size of ro-ro

ships in Indonesia compared to previous studies.

For upcoming studies, the correlation between the

LM and the main dimensions of the ro-ro ship above

2000 GT could be more analysed. After obtaining the

main dimensions of the ro-ro ship, further analysis on

the relationship between the LM and the weight of the

ship can be carried out. This is considered very

helpful for the ship design process. After obtaining

the main size and the weight of the ro-ro ship, the

construction costs can be estimated.

ACKNOWLEDGEMENT

The authors would like to thank PT. ASDP Indonesia

Ferry (Persero), PT. Flobamor, PD. Panca Karya,

Daya Radar Utama Shipyard, and Adiluhung

Shipyard, and Biro Klasifikasi Indonesia as well for

assisting and enabling the Authors to collect primary

data for this research.

REFERENCES

Asri, S. (2016). Klaster Tonase Kapal Ferry Ro-Ro dan

Pengaruhnya Terhadap Kebutuhan Lahan Perairan

Pelabuhan Penyeberangan (in Bahasa). Jurnal Riset

Teknologi Kelautan, 49- 60.

Direktorat Jenderal Perhubungan Darat. (1994). Petunjuk

Teknis Persyaratan Pelayanan Minimal Kapal Sungai,

Danau dan Penyeberangan (in Bahasa). Jakarta:

Departemen Perhubungan.

ibiblio. (2008, Desember 18). units:L. Retrieved from

Ibiblioc: The Public's Library and Digital Archive:

http://www.ibiblio.org/units/dictL.html

IFA. (2006, 06 20). Glossary - Lane Meter. Retrieved from

IFA - International Forwarding Agent s.r.l.:

http://www.ifaitaly.com/en/links/glossary/603- lane-

meter.html

IMO. (1969). The International Convention on Tonnage

Measurement of Ships. London: International Maritime

Organization.

Kristensen, H. O. (2006). Cargo Transport by Sea and Road

— Technical and Economical Environmental Factors.

Naval Engineers Journal, 115-129.

Kristensen, H. O. (2016). Analysis of technical data of Ro-

Ro ships. Kongens Lyngby: HOK Marineconsult ApS.

Marine Environment Protection Committee. (2009).

Guidelines for Voluntary Use of the Ship Energy

Efficiency Operational Indicator (EEOI) - 3

Definitions. London: International Maritime

Organization.

Menteri Perhubungan R.I. (2002). Tatanan Kepelabuhanan

Nasional - Keputusan Menteri Perhubungan No KM 53

Tahun 2002 (in Bahasa). Jakarta: Kementerian

Perhubungan Republik Indonesia.

Walpole, R. E. (2012). Probability & Statistics for

Engineers & Scientists : Ninth Edition. Boston:

Prentice Hall.

Wathne, E. (2012). Cargo Stowage Planning in RoRo

Shipping : Optimisation Based Naval Architecture.

Trondheim: Norwegian University of Science and

Technology.

Watson, D. G. (1998). Practical Ship Design. Oxford:

Butterworth Heinemann.

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